Validation Controls, Override/append Client Side Functionality

I

IfThenElse

Hello,

I am wondering how can I Override/Append to the Client Side JavaScript of a
System.Web.UI.WebControls.RequiredFieldValidator Control.

I actually need to only add few lines of JavaScript to the Microsoft
Supplied JavaScript Function.

So I need to Just extend it to do one or two extra things for me.

I know I can create a new Validation Control to do such thing but I wonder
If I can Inherit the exiting functionality.

If I inherit the "System.Web.UI.WebControls.RequiredFieldValidator" How can
I call the base class JavaScript that does the validation and then add some
more to it.

I have seen Scott Michell's "Creating Validator Controls for CheckBox"
etc... No inheritance because there was none. So the example does not
answer my needs.


thanks
 
S

Shelly

IfThenElse said:
Hello,

I am wondering how can I Override/Append to the Client Side JavaScript of
a System.Web.UI.WebControls.RequiredFieldValidator Control.

I actually need to only add few lines of JavaScript to the Microsoft
Supplied JavaScript Function.

So I need to Just extend it to do one or two extra things for me.

I know I can create a new Validation Control to do such thing but I wonder
If I can Inherit the exiting functionality.

If I inherit the "System.Web.UI.WebControls.RequiredFieldValidator" How
can I call the base class JavaScript that does the validation and then add
some more to it.

I have seen Scott Michell's "Creating Validator Controls for CheckBox"
etc... No inheritance because there was none. So the example does not
answer my needs.
Click to expand...

I'm guessing, mind you, and have never done this, but from what I **just**
learned could you encapusate that validation control inside a user control
where you add what you need in the code-behind section?

Shelly
 
I

IfThenElse

Shelly,

No, This is a built in server control
"System.Web.UI.WebControls.RequiredFieldValidator"
I want to inherit it and add just functionality for the client side
JavaScript only but still calling the base-JavaScript-function that M.S.
provided.

encapsulate that validation control inside a user control will not work for
me. I am looking for a more elegant solution.

I can rewrite the entire control as
System.Web.UI.WebControls.MyRequiredFieldValidator but I was hoping to
inherit.

Thanks for you reply.
 
B

bruce barker

there is no support for inheriting. the required validator javascript is
in a resource file that is downloaded if you use validation.

to do what you want is simple:

<script>
function myRequired(s,a)
{
a.IsValid = true;
rq = document.getElementById('<%=rqMS%>');
if (!rq.evaluationfunction(s,a))
a.IsValid = false;
else
{
// my additional test
}
return a.IsValid
}
</script>

<!-- need one dummy rq validator -->

<asp:RequiredFieldValidator
id=rqMS
runat=server
enabled=false
controltovalidate=foo />

<asp:customvalidator
runat=server
controltovalidate=foo
clientvalidationfunction="myRequired"
errormessage="required" />
<asp:textbox id=foo runat="server" />
<asp:customvalidator
runat=server
controltovalidate=foo2
clientvalidationfunction="myRequired"
errormessage="required" />
<asp:textbox id=foo2 runat="server" />

-- bruce (sqlwork.com)
 
I

IfThenElse

Hi Bruce,

I am already using a custom validator to deal with this issue.
I was hoping to not use any dummies.
I have many fields to validate ( required, RegExp, etc...)

All I want to do is not to add more validation at the end but to scroll the
window to a better "cosmetically" nicer position when validation fails and
focus on error is set to true.

I wish M.S. added one more property to each Validation function that allows
you to move the window scroll to some href#tag after focusing on Validation
Failure.

I hope I was clear.

Any other Ideas.

Thank You,
 
T

Teemu Keiski

Hi,

In ASP.NEt 2.0 RequiredFieldValidatorIsValid is defined in System.Web
assembly's resources (WebUIValidation.js). it looks like:

function RequiredFieldValidatorEvaluateIsValid(val) {
return (ValidatorTrim(ValidatorGetValue(val.controltovalidate)) !=
ValidatorTrim(val.initialvalue))
}

You can do a function pointer switch in JavaScript. Basically first create a
member to point to the old function, then create your new function which can
use the previous member in case it needs to call the default
implementation/method. Then assign your new method to the original function.
In pseudo-code something like:

//Reference the original method
var fxRequiredFieldValidatorIsValid = RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original method,
just note that you shoul return a boolean to indicate the validation
outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

However in this case, in ASP.NEt 2.0, reference to the used function is
stored in as member of the validator element itself. If you check the markup
it can look like:

var ctl02 = document.all ? document.all["ctl02"] :
document.getElementById("ctl02");
ctl02.controltovalidate = "ddlAccomodationCountry";
ctl02.errormessage = "Make a selection";
ctl02.evaluationfunction = "RequiredFieldValidatorEvaluateIsValid";
ctl02.initialvalue = "0";

Note especially evaluationfunction attribute.

So just assigning

RequiredFieldValidator = MyRequiredFieldValidatorIsValid;

doesn't in fact seem to work. However you can write instead

<body onload="myLoad()">

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

******* complete test page *********

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body onload="myLoad()">
<form id="form1" runat="server">
<div>

<asp:DropDownList ID="ddlAccomodationCountry" runat="server">
<asp:ListItem Value="0" Text="Please make a selection" />
<asp:ListItem Value="1" Text="Country 1" />
<asp:ListItem Value="2" Text="Country 2" />
<asp:ListItem Value="3" Text="Country 3" />
</asp:DropDownList>

<asp:RequiredFieldValidator ControlToValidate="ddlAccomodationCountry"
InitialValue="0" runat="server" ErrorMessage="Make a selection" />

<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:ValidationSummary ID="ValidationSummary1" runat="server" />

</div>
</form>
<script type="text/javascript">

//Reference the original method
var fxRequiredFieldValidatorIsValid = RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original method,
just note that you shoul return a boolean to indicate the validation
outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

</script>
</body>
</html>

*** test page ends ***

Remember to always check Page.IsValid in server-side code too.
 
I

IfThenElse

Teemu,

What I would like to specifically is:

If Validation Fails and I have set Focus on Error to True
I want to add just a document.location.href = "my#Tag";

I wonder when does and where does the focus occur in what function.

After the Focus on the first Invalid Field I want to be able to issue
document.location.href = .... for that specific field.
This is just cosmetically to adjust the screen or webpage vertical position.
I am doing it now but with too much work, adding custom validator for many
of my field controls some as groups.


the value of document.location.href if different for different Fields on
my Form but always on the same page.

I am hoping to find a better, faster, easier solution so for any future web
pages. this will save me lots of time.

Thank you for any further input.



Teemu Keiski said:
Hi,

In ASP.NEt 2.0 RequiredFieldValidatorIsValid is defined in System.Web
assembly's resources (WebUIValidation.js). it looks like:

function RequiredFieldValidatorEvaluateIsValid(val) {
return (ValidatorTrim(ValidatorGetValue(val.controltovalidate)) !=
ValidatorTrim(val.initialvalue))
}

You can do a function pointer switch in JavaScript. Basically first create
a member to point to the old function, then create your new function which
can use the previous member in case it needs to call the default
implementation/method. Then assign your new method to the original
function. In pseudo-code something like:

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original method,
just note that you shoul return a boolean to indicate the validation
outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

However in this case, in ASP.NEt 2.0, reference to the used function is
stored in as member of the validator element itself. If you check the
markup it can look like:

var ctl02 = document.all ? document.all["ctl02"] :
document.getElementById("ctl02");
ctl02.controltovalidate = "ddlAccomodationCountry";
ctl02.errormessage = "Make a selection";
ctl02.evaluationfunction = "RequiredFieldValidatorEvaluateIsValid";
ctl02.initialvalue = "0";

Note especially evaluationfunction attribute.

So just assigning

RequiredFieldValidator = MyRequiredFieldValidatorIsValid;

doesn't in fact seem to work. However you can write instead

<body onload="myLoad()">

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

******* complete test page *********

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body onload="myLoad()">
<form id="form1" runat="server">
<div>

<asp:DropDownList ID="ddlAccomodationCountry" runat="server">
<asp:ListItem Value="0" Text="Please make a selection" />
<asp:ListItem Value="1" Text="Country 1" />
<asp:ListItem Value="2" Text="Country 2" />
<asp:ListItem Value="3" Text="Country 3" />
</asp:DropDownList>

<asp:RequiredFieldValidator ControlToValidate="ddlAccomodationCountry"
InitialValue="0" runat="server" ErrorMessage="Make a selection" />

<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:ValidationSummary ID="ValidationSummary1" runat="server" />

</div>
</form>
<script type="text/javascript">

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original method,
just note that you shoul return a boolean to indicate the validation
outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

</script>
</body>
</html>

*** test page ends ***

Remember to always check Page.IsValid in server-side code too.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


IfThenElse said:
Hello,

I am wondering how can I Override/Append to the Client Side JavaScript of
a System.Web.UI.WebControls.RequiredFieldValidator Control.

I actually need to only add few lines of JavaScript to the Microsoft
Supplied JavaScript Function.

So I need to Just extend it to do one or two extra things for me.

I know I can create a new Validation Control to do such thing but I
wonder If I can Inherit the exiting functionality.

If I inherit the "System.Web.UI.WebControls.RequiredFieldValidator" How
can I call the base class JavaScript that does the validation and then
add some more to it.

I have seen Scott Michell's "Creating Validator Controls for CheckBox"
etc... No inheritance because there was none. So the example does not
answer my needs.


thanks
Click to expand...
Click to expand...
 
T

Teemu Keiski

If you use Reflector disassebler tool, you can view the resource file your
self. The method which sets focus in error case is ValidatorSetFocus

function ValidatorSetFocus(val, event) {
var ctrl;
if (typeof(val.controlhookup) == "string") {
var eventCtrl;
if ((typeof(event) != "undefined") && (event != null)) {
if ((typeof(event.srcElement) != "undefined") &&
(event.srcElement != null)) {
eventCtrl = event.srcElement;
}
else {
eventCtrl = event.target;
}
}
if ((typeof(eventCtrl) != "undefined") && (eventCtrl != null) &&
(typeof(eventCtrl.id) == "string") &&
(eventCtrl.id == val.controlhookup)) {
ctrl = eventCtrl;
}
}
if ((typeof(ctrl) == "undefined") || (ctrl == null)) {
ctrl = document.getElementById(val.controltovalidate);
}
if ((typeof(ctrl) != "undefined") && (ctrl != null) &&
(ctrl.tagName.toLowerCase() != "table" || (typeof(event) ==
"undefined") || (event == null)) &&
((ctrl.tagName.toLowerCase() != "input") || (ctrl.type.toLowerCase()
!= "hidden")) &&
(typeof(ctrl.disabled) == "undefined" || ctrl.disabled == null ||
ctrl.disabled == false) &&
(typeof(ctrl.visible) == "undefined" || ctrl.visible == null ||
ctrl.visible != false) &&
(IsInVisibleContainer(ctrl))) {
if (ctrl.tagName.toLowerCase() == "table" &&
(typeof(__nonMSDOMBrowser) == "undefined" || __nonMSDOMBrowser))
{
var inputElements = ctrl.getElementsByTagName("input");
var lastInputElement = inputElements[inputElements.length -1];
if (lastInputElement != null) {
ctrl = lastInputElement;
}
}
if (typeof(ctrl.focus) != "undefined" && ctrl.focus != null) {
ctrl.focus();
Page_InvalidControlToBeFocused = ctrl;
}
}
}

and it is triggered by ValidatorValidate

function ValidatorValidate(val, validationGroup, event) {

So I think what you want to achieve isn't too far.

I think you should be able just reset the focused control's focus() method
with similar tactics to set the anchor position.

obj.focus = yourfunction;


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net



IfThenElse said:
Teemu,

What I would like to specifically is:

If Validation Fails and I have set Focus on Error to True
I want to add just a document.location.href = "my#Tag";

I wonder when does and where does the focus occur in what function.

After the Focus on the first Invalid Field I want to be able to issue
document.location.href = .... for that specific field.
This is just cosmetically to adjust the screen or webpage vertical
position.
I am doing it now but with too much work, adding custom validator for many
of my field controls some as groups.


the value of document.location.href if different for different Fields
on my Form but always on the same page.

I am hoping to find a better, faster, easier solution so for any future
web pages. this will save me lots of time.

Thank you for any further input.



Teemu Keiski said:
Hi,

In ASP.NEt 2.0 RequiredFieldValidatorIsValid is defined in System.Web
assembly's resources (WebUIValidation.js). it looks like:

function RequiredFieldValidatorEvaluateIsValid(val) {
return (ValidatorTrim(ValidatorGetValue(val.controltovalidate)) !=
ValidatorTrim(val.initialvalue))
}

You can do a function pointer switch in JavaScript. Basically first
create a member to point to the old function, then create your new
function which can use the previous member in case it needs to call the
default implementation/method. Then assign your new method to the
original function. In pseudo-code something like:

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

However in this case, in ASP.NEt 2.0, reference to the used function is
stored in as member of the validator element itself. If you check the
markup it can look like:

var ctl02 = document.all ? document.all["ctl02"] :
document.getElementById("ctl02");
ctl02.controltovalidate = "ddlAccomodationCountry";
ctl02.errormessage = "Make a selection";
ctl02.evaluationfunction = "RequiredFieldValidatorEvaluateIsValid";
ctl02.initialvalue = "0";

Note especially evaluationfunction attribute.

So just assigning

RequiredFieldValidator = MyRequiredFieldValidatorIsValid;

doesn't in fact seem to work. However you can write instead

<body onload="myLoad()">

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

******* complete test page *********

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body onload="myLoad()">
<form id="form1" runat="server">
<div>

<asp:DropDownList ID="ddlAccomodationCountry" runat="server">
<asp:ListItem Value="0" Text="Please make a selection" />
<asp:ListItem Value="1" Text="Country 1" />
<asp:ListItem Value="2" Text="Country 2" />
<asp:ListItem Value="3" Text="Country 3" />
</asp:DropDownList>

<asp:RequiredFieldValidator ControlToValidate="ddlAccomodationCountry"
InitialValue="0" runat="server" ErrorMessage="Make a selection" />

<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:ValidationSummary ID="ValidationSummary1" runat="server" />

</div>
</form>
<script type="text/javascript">

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

</script>
</body>
</html>

*** test page ends ***

Remember to always check Page.IsValid in server-side code too.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


IfThenElse said:
Hello,

I am wondering how can I Override/Append to the Client Side JavaScript
of a System.Web.UI.WebControls.RequiredFieldValidator Control.

I actually need to only add few lines of JavaScript to the Microsoft
Supplied JavaScript Function.

So I need to Just extend it to do one or two extra things for me.

I know I can create a new Validation Control to do such thing but I
wonder If I can Inherit the exiting functionality.

If I inherit the "System.Web.UI.WebControls.RequiredFieldValidator" How
can I call the base class JavaScript that does the validation and then
add some more to it.

I have seen Scott Michell's "Creating Validator Controls for CheckBox"
etc... No inheritance because there was none. So the example does not
answer my needs.


thanks
Click to expand...
Click to expand...
Click to expand...
 
I

IfThenElse

Teemu,

Originally I added the property off OnFocus="MyFocusFunction" for each
field in my form .
this was setting the Focus whether the control received the focus due to
user clicking in a textbox or tabbing to a text box. ( textbox for example)
Somehow I did not want that functionality.
Now I am thinking, I can do the same thing, but check first if the field got
focus and it is or was Invalid then I can do my window.location.href =
MyTag#OnTheWebPage.

I don't remember but I think I had some issues with that Idea of
OnFocus="myfocusfunction" but I don't remember what. I am revisiting as
soon as time allows.

I am also trying to understand the function ValidatorSetFocus(val, event){}
do you know where the definitions are for the val and event Parameters?

background: I can do JavaScript but I don't know it well yet...

Using reflector, can you give me a one sentence on how to use it please?

Thank you for your input and help..... it has and will be useful for me.



Teemu Keiski said:
If you use Reflector disassebler tool, you can view the resource file your
self. The method which sets focus in error case is ValidatorSetFocus

function ValidatorSetFocus(val, event) {
var ctrl;
if (typeof(val.controlhookup) == "string") {
var eventCtrl;
if ((typeof(event) != "undefined") && (event != null)) {
if ((typeof(event.srcElement) != "undefined") &&
(event.srcElement != null)) {
eventCtrl = event.srcElement;
}
else {
eventCtrl = event.target;
}
}
if ((typeof(eventCtrl) != "undefined") && (eventCtrl != null) &&
(typeof(eventCtrl.id) == "string") &&
(eventCtrl.id == val.controlhookup)) {
ctrl = eventCtrl;
}
}
if ((typeof(ctrl) == "undefined") || (ctrl == null)) {
ctrl = document.getElementById(val.controltovalidate);
}
if ((typeof(ctrl) != "undefined") && (ctrl != null) &&
(ctrl.tagName.toLowerCase() != "table" || (typeof(event) ==
"undefined") || (event == null)) &&
((ctrl.tagName.toLowerCase() != "input") ||
(ctrl.type.toLowerCase() != "hidden")) &&
(typeof(ctrl.disabled) == "undefined" || ctrl.disabled == null ||
ctrl.disabled == false) &&
(typeof(ctrl.visible) == "undefined" || ctrl.visible == null ||
ctrl.visible != false) &&
(IsInVisibleContainer(ctrl))) {
if (ctrl.tagName.toLowerCase() == "table" &&
(typeof(__nonMSDOMBrowser) == "undefined" ||
__nonMSDOMBrowser)) {
var inputElements = ctrl.getElementsByTagName("input");
var lastInputElement = inputElements[inputElements.length -1];
if (lastInputElement != null) {
ctrl = lastInputElement;
}
}
if (typeof(ctrl.focus) != "undefined" && ctrl.focus != null) {
ctrl.focus();
Page_InvalidControlToBeFocused = ctrl;
}
}
}

and it is triggered by ValidatorValidate

function ValidatorValidate(val, validationGroup, event) {

So I think what you want to achieve isn't too far.

I think you should be able just reset the focused control's focus() method
with similar tactics to set the anchor position.

obj.focus = yourfunction;


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net



IfThenElse said:
Teemu,

What I would like to specifically is:

If Validation Fails and I have set Focus on Error to True
I want to add just a document.location.href = "my#Tag";

I wonder when does and where does the focus occur in what function.

After the Focus on the first Invalid Field I want to be able to issue
document.location.href = .... for that specific field.
This is just cosmetically to adjust the screen or webpage vertical
position.
I am doing it now but with too much work, adding custom validator for
many of my field controls some as groups.


the value of document.location.href if different for different Fields
on my Form but always on the same page.

I am hoping to find a better, faster, easier solution so for any future
web pages. this will save me lots of time.

Thank you for any further input.



Teemu Keiski said:
Hi,

In ASP.NEt 2.0 RequiredFieldValidatorIsValid is defined in System.Web
assembly's resources (WebUIValidation.js). it looks like:

function RequiredFieldValidatorEvaluateIsValid(val) {
return (ValidatorTrim(ValidatorGetValue(val.controltovalidate)) !=
ValidatorTrim(val.initialvalue))
}

You can do a function pointer switch in JavaScript. Basically first
create a member to point to the old function, then create your new
function which can use the previous member in case it needs to call the
default implementation/method. Then assign your new method to the
original function. In pseudo-code something like:

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

However in this case, in ASP.NEt 2.0, reference to the used function is
stored in as member of the validator element itself. If you check the
markup it can look like:

var ctl02 = document.all ? document.all["ctl02"] :
document.getElementById("ctl02");
ctl02.controltovalidate = "ddlAccomodationCountry";
ctl02.errormessage = "Make a selection";
ctl02.evaluationfunction = "RequiredFieldValidatorEvaluateIsValid";
ctl02.initialvalue = "0";

Note especially evaluationfunction attribute.

So just assigning

RequiredFieldValidator = MyRequiredFieldValidatorIsValid;

doesn't in fact seem to work. However you can write instead

<body onload="myLoad()">

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

******* complete test page *********

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body onload="myLoad()">
<form id="form1" runat="server">
<div>

<asp:DropDownList ID="ddlAccomodationCountry" runat="server">
<asp:ListItem Value="0" Text="Please make a selection" />
<asp:ListItem Value="1" Text="Country 1" />
<asp:ListItem Value="2" Text="Country 2" />
<asp:ListItem Value="3" Text="Country 3" />
</asp:DropDownList>

<asp:RequiredFieldValidator ControlToValidate="ddlAccomodationCountry"
InitialValue="0" runat="server" ErrorMessage="Make a selection" />

<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:ValidationSummary ID="ValidationSummary1" runat="server" />

</div>
</form>
<script type="text/javascript">

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

</script>
</body>
</html>

*** test page ends ***

Remember to always check Page.IsValid in server-side code too.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Hello,

I am wondering how can I Override/Append to the Client Side JavaScript
of a System.Web.UI.WebControls.RequiredFieldValidator Control.

I actually need to only add few lines of JavaScript to the Microsoft
Supplied JavaScript Function.

So I need to Just extend it to do one or two extra things for me.

I know I can create a new Validation Control to do such thing but I
wonder If I can Inherit the exiting functionality.

If I inherit the "System.Web.UI.WebControls.RequiredFieldValidator"
How can I call the base class JavaScript that does the validation and
then add some more to it.

I have seen Scott Michell's "Creating Validator Controls for CheckBox"
etc... No inheritance because there was none. So the example does not
answer my needs.


thanks
Click to expand...
Click to expand...
Click to expand...
 
I

IfThenElse

Hi Teemu,

in the function function MyRequiredFieldValidatorIsValid(val)
{ .... } below

How do I get the current control or its Id that is being validated. or the
group_id from within the MyRequiredFieldValidatorIsValid(val)
function???

val mean Value but how about the control itself.

Thank you,


Teemu Keiski said:
Hi,

In ASP.NEt 2.0 RequiredFieldValidatorIsValid is defined in System.Web
assembly's resources (WebUIValidation.js). it looks like:

function RequiredFieldValidatorEvaluateIsValid(val) {
return (ValidatorTrim(ValidatorGetValue(val.controltovalidate)) !=
ValidatorTrim(val.initialvalue))
}

You can do a function pointer switch in JavaScript. Basically first create
a member to point to the old function, then create your new function which
can use the previous member in case it needs to call the default
implementation/method. Then assign your new method to the original
function. In pseudo-code something like:

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original method,
just note that you shoul return a boolean to indicate the validation
outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

However in this case, in ASP.NEt 2.0, reference to the used function is
stored in as member of the validator element itself. If you check the
markup it can look like:

var ctl02 = document.all ? document.all["ctl02"] :
document.getElementById("ctl02");
ctl02.controltovalidate = "ddlAccomodationCountry";
ctl02.errormessage = "Make a selection";
ctl02.evaluationfunction = "RequiredFieldValidatorEvaluateIsValid";
ctl02.initialvalue = "0";

Note especially evaluationfunction attribute.

So just assigning

RequiredFieldValidator = MyRequiredFieldValidatorIsValid;

doesn't in fact seem to work. However you can write instead

<body onload="myLoad()">

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

******* complete test page *********

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body onload="myLoad()">
<form id="form1" runat="server">
<div>

<asp:DropDownList ID="ddlAccomodationCountry" runat="server">
<asp:ListItem Value="0" Text="Please make a selection" />
<asp:ListItem Value="1" Text="Country 1" />
<asp:ListItem Value="2" Text="Country 2" />
<asp:ListItem Value="3" Text="Country 3" />
</asp:DropDownList>

<asp:RequiredFieldValidator ControlToValidate="ddlAccomodationCountry"
InitialValue="0" runat="server" ErrorMessage="Make a selection" />

<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:ValidationSummary ID="ValidationSummary1" runat="server" />

</div>
</form>
<script type="text/javascript">

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original method,
just note that you shoul return a boolean to indicate the validation
outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

</script>
</body>
</html>

*** test page ends ***

Remember to always check Page.IsValid in server-side code too.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


IfThenElse said:
Hello,

I am wondering how can I Override/Append to the Client Side JavaScript of
a System.Web.UI.WebControls.RequiredFieldValidator Control.

I actually need to only add few lines of JavaScript to the Microsoft
Supplied JavaScript Function.

So I need to Just extend it to do one or two extra things for me.

I know I can create a new Validation Control to do such thing but I
wonder If I can Inherit the exiting functionality.

If I inherit the "System.Web.UI.WebControls.RequiredFieldValidator" How
can I call the base class JavaScript that does the validation and then
add some more to it.

I have seen Scott Michell's "Creating Validator Controls for CheckBox"
etc... No inheritance because there was none. So the example does not
answer my needs.


thanks
Click to expand...
Click to expand...
 
T

Teemu Keiski

val.controltovalidate should return you the control which the validator is
validating.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


IfThenElse said:
Hi Teemu,

in the function function MyRequiredFieldValidatorIsValid(val)
{ .... } below

How do I get the current control or its Id that is being validated. or
the group_id from within the MyRequiredFieldValidatorIsValid(val)
function???

val mean Value but how about the control itself.

Thank you,


Teemu Keiski said:
Hi,

In ASP.NEt 2.0 RequiredFieldValidatorIsValid is defined in System.Web
assembly's resources (WebUIValidation.js). it looks like:

function RequiredFieldValidatorEvaluateIsValid(val) {
return (ValidatorTrim(ValidatorGetValue(val.controltovalidate)) !=
ValidatorTrim(val.initialvalue))
}

You can do a function pointer switch in JavaScript. Basically first
create a member to point to the old function, then create your new
function which can use the previous member in case it needs to call the
default implementation/method. Then assign your new method to the
original function. In pseudo-code something like:

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

However in this case, in ASP.NEt 2.0, reference to the used function is
stored in as member of the validator element itself. If you check the
markup it can look like:

var ctl02 = document.all ? document.all["ctl02"] :
document.getElementById("ctl02");
ctl02.controltovalidate = "ddlAccomodationCountry";
ctl02.errormessage = "Make a selection";
ctl02.evaluationfunction = "RequiredFieldValidatorEvaluateIsValid";
ctl02.initialvalue = "0";

Note especially evaluationfunction attribute.

So just assigning

RequiredFieldValidator = MyRequiredFieldValidatorIsValid;

doesn't in fact seem to work. However you can write instead

<body onload="myLoad()">

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

******* complete test page *********

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body onload="myLoad()">
<form id="form1" runat="server">
<div>

<asp:DropDownList ID="ddlAccomodationCountry" runat="server">
<asp:ListItem Value="0" Text="Please make a selection" />
<asp:ListItem Value="1" Text="Country 1" />
<asp:ListItem Value="2" Text="Country 2" />
<asp:ListItem Value="3" Text="Country 3" />
</asp:DropDownList>

<asp:RequiredFieldValidator ControlToValidate="ddlAccomodationCountry"
InitialValue="0" runat="server" ErrorMessage="Make a selection" />

<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:ValidationSummary ID="ValidationSummary1" runat="server" />

</div>
</form>
<script type="text/javascript">

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

</script>
</body>
</html>

*** test page ends ***

Remember to always check Page.IsValid in server-side code too.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


IfThenElse said:
Hello,

I am wondering how can I Override/Append to the Client Side JavaScript
of a System.Web.UI.WebControls.RequiredFieldValidator Control.

I actually need to only add few lines of JavaScript to the Microsoft
Supplied JavaScript Function.

So I need to Just extend it to do one or two extra things for me.

I know I can create a new Validation Control to do such thing but I
wonder If I can Inherit the exiting functionality.

If I inherit the "System.Web.UI.WebControls.RequiredFieldValidator" How
can I call the base class JavaScript that does the validation and then
add some more to it.

I have seen Scott Michell's "Creating Validator Controls for CheckBox"
etc... No inheritance because there was none. So the example does not
answer my needs.


thanks
Click to expand...
Click to expand...
Click to expand...
 
T

Teemu Keiski

If you have reflector from here:
http://www.aisto.com/roeder/dotnet/

Open it and if it asks specify 2.0 as Framework version (you can change that
later plus also view same assemblies from different FX versions). You should
have System.Web assembly already in the tree, expand it. Under it you'll
find Resources node, expand it also and locate WebUIValidation.js (it'd on
bottom) Right click on top of it and choose "View Resource"


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net




IfThenElse said:
Teemu,

Originally I added the property off OnFocus="MyFocusFunction" for each
field in my form .
this was setting the Focus whether the control received the focus due to
user clicking in a textbox or tabbing to a text box. ( textbox for
example)
Somehow I did not want that functionality.
Now I am thinking, I can do the same thing, but check first if the field
got focus and it is or was Invalid then I can do my window.location.href =
MyTag#OnTheWebPage.

I don't remember but I think I had some issues with that Idea of
OnFocus="myfocusfunction" but I don't remember what. I am revisiting as
soon as time allows.

I am also trying to understand the function ValidatorSetFocus(val,
event){}
do you know where the definitions are for the val and event Parameters?

background: I can do JavaScript but I don't know it well yet...

Using reflector, can you give me a one sentence on how to use it please?

Thank you for your input and help..... it has and will be useful for me.



Teemu Keiski said:
If you use Reflector disassebler tool, you can view the resource file
your self. The method which sets focus in error case is ValidatorSetFocus

function ValidatorSetFocus(val, event) {
var ctrl;
if (typeof(val.controlhookup) == "string") {
var eventCtrl;
if ((typeof(event) != "undefined") && (event != null)) {
if ((typeof(event.srcElement) != "undefined") &&
(event.srcElement != null)) {
eventCtrl = event.srcElement;
}
else {
eventCtrl = event.target;
}
}
if ((typeof(eventCtrl) != "undefined") && (eventCtrl != null) &&
(typeof(eventCtrl.id) == "string") &&
(eventCtrl.id == val.controlhookup)) {
ctrl = eventCtrl;
}
}
if ((typeof(ctrl) == "undefined") || (ctrl == null)) {
ctrl = document.getElementById(val.controltovalidate);
}
if ((typeof(ctrl) != "undefined") && (ctrl != null) &&
(ctrl.tagName.toLowerCase() != "table" || (typeof(event) ==
"undefined") || (event == null)) &&
((ctrl.tagName.toLowerCase() != "input") ||
(ctrl.type.toLowerCase() != "hidden")) &&
(typeof(ctrl.disabled) == "undefined" || ctrl.disabled == null ||
ctrl.disabled == false) &&
(typeof(ctrl.visible) == "undefined" || ctrl.visible == null ||
ctrl.visible != false) &&
(IsInVisibleContainer(ctrl))) {
if (ctrl.tagName.toLowerCase() == "table" &&
(typeof(__nonMSDOMBrowser) == "undefined" ||
__nonMSDOMBrowser)) {
var inputElements = ctrl.getElementsByTagName("input");
var lastInputElement =
inputElements[inputElements.length -1];
if (lastInputElement != null) {
ctrl = lastInputElement;
}
}
if (typeof(ctrl.focus) != "undefined" && ctrl.focus != null) {
ctrl.focus();
Page_InvalidControlToBeFocused = ctrl;
}
}
}

and it is triggered by ValidatorValidate

function ValidatorValidate(val, validationGroup, event) {

So I think what you want to achieve isn't too far.

I think you should be able just reset the focused control's focus()
method with similar tactics to set the anchor position.

obj.focus = yourfunction;


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net



IfThenElse said:
Teemu,

What I would like to specifically is:

If Validation Fails and I have set Focus on Error to True
I want to add just a document.location.href = "my#Tag";

I wonder when does and where does the focus occur in what function.

After the Focus on the first Invalid Field I want to be able to issue
document.location.href = .... for that specific field.
This is just cosmetically to adjust the screen or webpage vertical
position.
I am doing it now but with too much work, adding custom validator for
many of my field controls some as groups.


the value of document.location.href if different for different
Fields on my Form but always on the same page.

I am hoping to find a better, faster, easier solution so for any future
web pages. this will save me lots of time.

Thank you for any further input.



Hi,

In ASP.NEt 2.0 RequiredFieldValidatorIsValid is defined in System.Web
assembly's resources (WebUIValidation.js). it looks like:

function RequiredFieldValidatorEvaluateIsValid(val) {
return (ValidatorTrim(ValidatorGetValue(val.controltovalidate)) !=
ValidatorTrim(val.initialvalue))
}

You can do a function pointer switch in JavaScript. Basically first
create a member to point to the old function, then create your new
function which can use the previous member in case it needs to call the
default implementation/method. Then assign your new method to the
original function. In pseudo-code something like:

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

However in this case, in ASP.NEt 2.0, reference to the used function is
stored in as member of the validator element itself. If you check the
markup it can look like:

var ctl02 = document.all ? document.all["ctl02"] :
document.getElementById("ctl02");
ctl02.controltovalidate = "ddlAccomodationCountry";
ctl02.errormessage = "Make a selection";
ctl02.evaluationfunction = "RequiredFieldValidatorEvaluateIsValid";
ctl02.initialvalue = "0";

Note especially evaluationfunction attribute.

So just assigning

RequiredFieldValidator = MyRequiredFieldValidatorIsValid;

doesn't in fact seem to work. However you can write instead

<body onload="myLoad()">

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

******* complete test page *********

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body onload="myLoad()">
<form id="form1" runat="server">
<div>

<asp:DropDownList ID="ddlAccomodationCountry" runat="server">
<asp:ListItem Value="0" Text="Please make a selection" />
<asp:ListItem Value="1" Text="Country 1" />
<asp:ListItem Value="2" Text="Country 2" />
<asp:ListItem Value="3" Text="Country 3" />
</asp:DropDownList>

<asp:RequiredFieldValidator ControlToValidate="ddlAccomodationCountry"
InitialValue="0" runat="server" ErrorMessage="Make a selection" />

<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:ValidationSummary ID="ValidationSummary1" runat="server" />

</div>
</form>
<script type="text/javascript">

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

</script>
</body>
</html>

*** test page ends ***

Remember to always check Page.IsValid in server-side code too.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Hello,

I am wondering how can I Override/Append to the Client Side JavaScript
of a System.Web.UI.WebControls.RequiredFieldValidator Control.

I actually need to only add few lines of JavaScript to the Microsoft
Supplied JavaScript Function.

So I need to Just extend it to do one or two extra things for me.

I know I can create a new Validation Control to do such thing but I
wonder If I can Inherit the exiting functionality.

If I inherit the "System.Web.UI.WebControls.RequiredFieldValidator"
How can I call the base class JavaScript that does the validation and
then add some more to it.

I have seen Scott Michell's "Creating Validator Controls for CheckBox"
etc... No inheritance because there was none. So the example does
not answer my needs.


thanks
Click to expand...
Click to expand...
Click to expand...
 
T

Teemu Keiski

To add, val refers to the client-side DOM element representing the
validator.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Teemu Keiski said:
val.controltovalidate should return you the control which the validator is
validating.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


IfThenElse said:
Hi Teemu,

in the function function MyRequiredFieldValidatorIsValid(val)
{ .... } below

How do I get the current control or its Id that is being validated. or
the group_id from within the MyRequiredFieldValidatorIsValid(val)
function???

val mean Value but how about the control itself.

Thank you,


Teemu Keiski said:
Hi,

In ASP.NEt 2.0 RequiredFieldValidatorIsValid is defined in System.Web
assembly's resources (WebUIValidation.js). it looks like:

function RequiredFieldValidatorEvaluateIsValid(val) {
return (ValidatorTrim(ValidatorGetValue(val.controltovalidate)) !=
ValidatorTrim(val.initialvalue))
}

You can do a function pointer switch in JavaScript. Basically first
create a member to point to the old function, then create your new
function which can use the previous member in case it needs to call the
default implementation/method. Then assign your new method to the
original function. In pseudo-code something like:

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

However in this case, in ASP.NEt 2.0, reference to the used function is
stored in as member of the validator element itself. If you check the
markup it can look like:

var ctl02 = document.all ? document.all["ctl02"] :
document.getElementById("ctl02");
ctl02.controltovalidate = "ddlAccomodationCountry";
ctl02.errormessage = "Make a selection";
ctl02.evaluationfunction = "RequiredFieldValidatorEvaluateIsValid";
ctl02.initialvalue = "0";

Note especially evaluationfunction attribute.

So just assigning

RequiredFieldValidator = MyRequiredFieldValidatorIsValid;

doesn't in fact seem to work. However you can write instead

<body onload="myLoad()">

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

******* complete test page *********

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body onload="myLoad()">
<form id="form1" runat="server">
<div>

<asp:DropDownList ID="ddlAccomodationCountry" runat="server">
<asp:ListItem Value="0" Text="Please make a selection" />
<asp:ListItem Value="1" Text="Country 1" />
<asp:ListItem Value="2" Text="Country 2" />
<asp:ListItem Value="3" Text="Country 3" />
</asp:DropDownList>

<asp:RequiredFieldValidator ControlToValidate="ddlAccomodationCountry"
InitialValue="0" runat="server" ErrorMessage="Make a selection" />

<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:ValidationSummary ID="ValidationSummary1" runat="server" />

</div>
</form>
<script type="text/javascript">

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

</script>
</body>
</html>

*** test page ends ***

Remember to always check Page.IsValid in server-side code too.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Hello,

I am wondering how can I Override/Append to the Client Side JavaScript
of a System.Web.UI.WebControls.RequiredFieldValidator Control.

I actually need to only add few lines of JavaScript to the Microsoft
Supplied JavaScript Function.

So I need to Just extend it to do one or two extra things for me.

I know I can create a new Validation Control to do such thing but I
wonder If I can Inherit the exiting functionality.

If I inherit the "System.Web.UI.WebControls.RequiredFieldValidator"
How can I call the base class JavaScript that does the validation and
then add some more to it.

I have seen Scott Michell's "Creating Validator Controls for CheckBox"
etc... No inheritance because there was none. So the example does not
answer my needs.


thanks
Click to expand...
Click to expand...
Click to expand...
 
I

IfThenElse

Hi Teemu,

Thank you for the
JavaScript-Function-Hijacking-delegating-hooking-intercepting trick.

I don't know what to call it you call it function pointer switching. Nice.

This works for me as a second option. because if Microsoft changes the name
of the JavaScript functions that I am using then my code no longer works.

Do you agree that the ValidatorSetFocus(val, event) is inefficient?
Since the focus should be on the First Validator that Fails, it seems that
it is Fired for every Failed Validator

Is there a function or can I do a switch at ValidationFinihed Event or
Function and get the First Validator That Failed Info?

Thank you for your valuable help.


Teemu Keiski said:
val.controltovalidate should return you the control which the validator is
validating.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


IfThenElse said:
Hi Teemu,

in the function function MyRequiredFieldValidatorIsValid(val)
{ .... } below

How do I get the current control or its Id that is being validated. or
the group_id from within the MyRequiredFieldValidatorIsValid(val)
function???

val mean Value but how about the control itself.

Thank you,


Teemu Keiski said:
Hi,

In ASP.NEt 2.0 RequiredFieldValidatorIsValid is defined in System.Web
assembly's resources (WebUIValidation.js). it looks like:

function RequiredFieldValidatorEvaluateIsValid(val) {
return (ValidatorTrim(ValidatorGetValue(val.controltovalidate)) !=
ValidatorTrim(val.initialvalue))
}

You can do a function pointer switch in JavaScript. Basically first
create a member to point to the old function, then create your new
function which can use the previous member in case it needs to call the
default implementation/method. Then assign your new method to the
original function. In pseudo-code something like:

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

However in this case, in ASP.NEt 2.0, reference to the used function is
stored in as member of the validator element itself. If you check the
markup it can look like:

var ctl02 = document.all ? document.all["ctl02"] :
document.getElementById("ctl02");
ctl02.controltovalidate = "ddlAccomodationCountry";
ctl02.errormessage = "Make a selection";
ctl02.evaluationfunction = "RequiredFieldValidatorEvaluateIsValid";
ctl02.initialvalue = "0";

Note especially evaluationfunction attribute.

So just assigning

RequiredFieldValidator = MyRequiredFieldValidatorIsValid;

doesn't in fact seem to work. However you can write instead

<body onload="myLoad()">

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

******* complete test page *********

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body onload="myLoad()">
<form id="form1" runat="server">
<div>

<asp:DropDownList ID="ddlAccomodationCountry" runat="server">
<asp:ListItem Value="0" Text="Please make a selection" />
<asp:ListItem Value="1" Text="Country 1" />
<asp:ListItem Value="2" Text="Country 2" />
<asp:ListItem Value="3" Text="Country 3" />
</asp:DropDownList>

<asp:RequiredFieldValidator ControlToValidate="ddlAccomodationCountry"
InitialValue="0" runat="server" ErrorMessage="Make a selection" />

<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:ValidationSummary ID="ValidationSummary1" runat="server" />

</div>
</form>
<script type="text/javascript">

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

</script>
</body>
</html>

*** test page ends ***

Remember to always check Page.IsValid in server-side code too.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Hello,

I am wondering how can I Override/Append to the Client Side JavaScript
of a System.Web.UI.WebControls.RequiredFieldValidator Control.

I actually need to only add few lines of JavaScript to the Microsoft
Supplied JavaScript Function.

So I need to Just extend it to do one or two extra things for me.

I know I can create a new Validation Control to do such thing but I
wonder If I can Inherit the exiting functionality.

If I inherit the "System.Web.UI.WebControls.RequiredFieldValidator"
How can I call the base class JavaScript that does the validation and
then add some more to it.

I have seen Scott Michell's "Creating Validator Controls for CheckBox"
etc... No inheritance because there was none. So the example does not
answer my needs.


thanks
Click to expand...
Click to expand...
Click to expand...
 
T

Teemu Keiski

Validation is initiated by calling Page_ClientValidate() or
Page_ClientValidate(group).

So maybe you could wire your own function to it - before calling to base
Page_ClientValidate set a flag to indicate that validation has initiated and
then in ValidatorSetFocus, when the flag is true (called the
ValidatorSetFocus for the first time) do what you need to do and set the
flag to false after that - e.g that logic runs only once and then in the
wired method - after the call to base.ClientValidate() - also set the flag
back to false.

It might also work that after call to wired Page_ClientValidate() (base
method), loop through Page_Validators array, and find the first failed
validator.

--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


IfThenElse said:
Hi Teemu,

Thank you for the
JavaScript-Function-Hijacking-delegating-hooking-intercepting trick.

I don't know what to call it you call it function pointer switching.
Nice.

This works for me as a second option. because if Microsoft changes the
name of the JavaScript functions that I am using then my code no longer
works.

Do you agree that the ValidatorSetFocus(val, event) is inefficient?
Since the focus should be on the First Validator that Fails, it seems that
it is Fired for every Failed Validator

Is there a function or can I do a switch at ValidationFinihed Event or
Function and get the First Validator That Failed Info?

Thank you for your valuable help.


Teemu Keiski said:
val.controltovalidate should return you the control which the validator
is validating.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


IfThenElse said:
Hi Teemu,

in the function function MyRequiredFieldValidatorIsValid(val)
{ .... } below

How do I get the current control or its Id that is being validated. or
the group_id from within the MyRequiredFieldValidatorIsValid(val)
function???

val mean Value but how about the control itself.

Thank you,


Hi,

In ASP.NEt 2.0 RequiredFieldValidatorIsValid is defined in System.Web
assembly's resources (WebUIValidation.js). it looks like:

function RequiredFieldValidatorEvaluateIsValid(val) {
return (ValidatorTrim(ValidatorGetValue(val.controltovalidate)) !=
ValidatorTrim(val.initialvalue))
}

You can do a function pointer switch in JavaScript. Basically first
create a member to point to the old function, then create your new
function which can use the previous member in case it needs to call the
default implementation/method. Then assign your new method to the
original function. In pseudo-code something like:

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

However in this case, in ASP.NEt 2.0, reference to the used function is
stored in as member of the validator element itself. If you check the
markup it can look like:

var ctl02 = document.all ? document.all["ctl02"] :
document.getElementById("ctl02");
ctl02.controltovalidate = "ddlAccomodationCountry";
ctl02.errormessage = "Make a selection";
ctl02.evaluationfunction = "RequiredFieldValidatorEvaluateIsValid";
ctl02.initialvalue = "0";

Note especially evaluationfunction attribute.

So just assigning

RequiredFieldValidator = MyRequiredFieldValidatorIsValid;

doesn't in fact seem to work. However you can write instead

<body onload="myLoad()">

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

******* complete test page *********

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body onload="myLoad()">
<form id="form1" runat="server">
<div>

<asp:DropDownList ID="ddlAccomodationCountry" runat="server">
<asp:ListItem Value="0" Text="Please make a selection" />
<asp:ListItem Value="1" Text="Country 1" />
<asp:ListItem Value="2" Text="Country 2" />
<asp:ListItem Value="3" Text="Country 3" />
</asp:DropDownList>

<asp:RequiredFieldValidator ControlToValidate="ddlAccomodationCountry"
InitialValue="0" runat="server" ErrorMessage="Make a selection" />

<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:ValidationSummary ID="ValidationSummary1" runat="server" />

</div>
</form>
<script type="text/javascript">

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

</script>
</body>
</html>

*** test page ends ***

Remember to always check Page.IsValid in server-side code too.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Hello,

I am wondering how can I Override/Append to the Client Side JavaScript
of a System.Web.UI.WebControls.RequiredFieldValidator Control.

I actually need to only add few lines of JavaScript to the Microsoft
Supplied JavaScript Function.

So I need to Just extend it to do one or two extra things for me.

I know I can create a new Validation Control to do such thing but I
wonder If I can Inherit the exiting functionality.

If I inherit the "System.Web.UI.WebControls.RequiredFieldValidator"
How can I call the base class JavaScript that does the validation and
then add some more to it.

I have seen Scott Michell's "Creating Validator Controls for CheckBox"
etc... No inheritance because there was none. So the example does
not answer my needs.


thanks
Click to expand...
Click to expand...
Click to expand...
 
I

IfThenElse

Thank you, will try it.


Teemu Keiski said:
If you have reflector from here:
http://www.aisto.com/roeder/dotnet/

Open it and if it asks specify 2.0 as Framework version (you can change
that later plus also view same assemblies from different FX versions). You
should have System.Web assembly already in the tree, expand it. Under it
you'll find Resources node, expand it also and locate WebUIValidation.js
(it'd on bottom) Right click on top of it and choose "View Resource"


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net




IfThenElse said:
Teemu,

Originally I added the property off OnFocus="MyFocusFunction" for each
field in my form .
this was setting the Focus whether the control received the focus due to
user clicking in a textbox or tabbing to a text box. ( textbox for
example)
Somehow I did not want that functionality.
Now I am thinking, I can do the same thing, but check first if the field
got focus and it is or was Invalid then I can do my window.location.href
= MyTag#OnTheWebPage.

I don't remember but I think I had some issues with that Idea of
OnFocus="myfocusfunction" but I don't remember what. I am revisiting as
soon as time allows.

I am also trying to understand the function ValidatorSetFocus(val,
event){}
do you know where the definitions are for the val and event Parameters?

background: I can do JavaScript but I don't know it well yet...

Using reflector, can you give me a one sentence on how to use it please?

Thank you for your input and help..... it has and will be useful for me.



Teemu Keiski said:
If you use Reflector disassebler tool, you can view the resource file
your self. The method which sets focus in error case is
ValidatorSetFocus

function ValidatorSetFocus(val, event) {
var ctrl;
if (typeof(val.controlhookup) == "string") {
var eventCtrl;
if ((typeof(event) != "undefined") && (event != null)) {
if ((typeof(event.srcElement) != "undefined") &&
(event.srcElement != null)) {
eventCtrl = event.srcElement;
}
else {
eventCtrl = event.target;
}
}
if ((typeof(eventCtrl) != "undefined") && (eventCtrl != null) &&
(typeof(eventCtrl.id) == "string") &&
(eventCtrl.id == val.controlhookup)) {
ctrl = eventCtrl;
}
}
if ((typeof(ctrl) == "undefined") || (ctrl == null)) {
ctrl = document.getElementById(val.controltovalidate);
}
if ((typeof(ctrl) != "undefined") && (ctrl != null) &&
(ctrl.tagName.toLowerCase() != "table" || (typeof(event) ==
"undefined") || (event == null)) &&
((ctrl.tagName.toLowerCase() != "input") ||
(ctrl.type.toLowerCase() != "hidden")) &&
(typeof(ctrl.disabled) == "undefined" || ctrl.disabled == null ||
ctrl.disabled == false) &&
(typeof(ctrl.visible) == "undefined" || ctrl.visible == null ||
ctrl.visible != false) &&
(IsInVisibleContainer(ctrl))) {
if (ctrl.tagName.toLowerCase() == "table" &&
(typeof(__nonMSDOMBrowser) == "undefined" ||
__nonMSDOMBrowser)) {
var inputElements = ctrl.getElementsByTagName("input");
var lastInputElement =
inputElements[inputElements.length -1];
if (lastInputElement != null) {
ctrl = lastInputElement;
}
}
if (typeof(ctrl.focus) != "undefined" && ctrl.focus != null) {
ctrl.focus();
Page_InvalidControlToBeFocused = ctrl;
}
}
}

and it is triggered by ValidatorValidate

function ValidatorValidate(val, validationGroup, event) {

So I think what you want to achieve isn't too far.

I think you should be able just reset the focused control's focus()
method with similar tactics to set the anchor position.

obj.focus = yourfunction;


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net



Teemu,

What I would like to specifically is:

If Validation Fails and I have set Focus on Error to True
I want to add just a document.location.href = "my#Tag";

I wonder when does and where does the focus occur in what function.

After the Focus on the first Invalid Field I want to be able to issue
document.location.href = .... for that specific field.
This is just cosmetically to adjust the screen or webpage vertical
position.
I am doing it now but with too much work, adding custom validator for
many of my field controls some as groups.


the value of document.location.href if different for different
Fields on my Form but always on the same page.

I am hoping to find a better, faster, easier solution so for any future
web pages. this will save me lots of time.

Thank you for any further input.



Hi,

In ASP.NEt 2.0 RequiredFieldValidatorIsValid is defined in System.Web
assembly's resources (WebUIValidation.js). it looks like:

function RequiredFieldValidatorEvaluateIsValid(val) {
return (ValidatorTrim(ValidatorGetValue(val.controltovalidate)) !=
ValidatorTrim(val.initialvalue))
}

You can do a function pointer switch in JavaScript. Basically first
create a member to point to the old function, then create your new
function which can use the previous member in case it needs to call
the default implementation/method. Then assign your new method to the
original function. In pseudo-code something like:

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

However in this case, in ASP.NEt 2.0, reference to the used function
is stored in as member of the validator element itself. If you check
the markup it can look like:

var ctl02 = document.all ? document.all["ctl02"] :
document.getElementById("ctl02");
ctl02.controltovalidate = "ddlAccomodationCountry";
ctl02.errormessage = "Make a selection";
ctl02.evaluationfunction = "RequiredFieldValidatorEvaluateIsValid";
ctl02.initialvalue = "0";

Note especially evaluationfunction attribute.

So just assigning

RequiredFieldValidator = MyRequiredFieldValidatorIsValid;

doesn't in fact seem to work. However you can write instead

<body onload="myLoad()">

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

******* complete test page *********

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body onload="myLoad()">
<form id="form1" runat="server">
<div>

<asp:DropDownList ID="ddlAccomodationCountry" runat="server">
<asp:ListItem Value="0" Text="Please make a selection" />
<asp:ListItem Value="1" Text="Country 1" />
<asp:ListItem Value="2" Text="Country 2" />
<asp:ListItem Value="3" Text="Country 3" />
</asp:DropDownList>

<asp:RequiredFieldValidator ControlToValidate="ddlAccomodationCountry"
InitialValue="0" runat="server" ErrorMessage="Make a selection" />

<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:ValidationSummary ID="ValidationSummary1" runat="server"
/>

</div>
</form>
<script type="text/javascript">

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

</script>
</body>
</html>

*** test page ends ***

Remember to always check Page.IsValid in server-side code too.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Hello,

I am wondering how can I Override/Append to the Client Side
JavaScript of a System.Web.UI.WebControls.RequiredFieldValidator
Control.

I actually need to only add few lines of JavaScript to the Microsoft
Supplied JavaScript Function.

So I need to Just extend it to do one or two extra things for me.

I know I can create a new Validation Control to do such thing but I
wonder If I can Inherit the exiting functionality.

If I inherit the "System.Web.UI.WebControls.RequiredFieldValidator"
How can I call the base class JavaScript that does the validation and
then add some more to it.

I have seen Scott Michell's "Creating Validator Controls for
CheckBox" etc... No inheritance because there was none. So the
example does not answer my needs.


thanks
Click to expand...
Click to expand...
Click to expand...
 
I

IfThenElse

Teemu,

I implemented the ValidatorSetFocus(val, event) Switch and that works.
However a bit of work.
For what I want that is better so far because it handles any validator ( not
only required Field. etc.. )

I will look into the Page_ClientValidate Functions switch soon.

I was wondering, How do I ask a Validator if it is valid or not.

I tried something like MyValidatorID.IsValid but that did not work for me.
Got undefined error.

MyValidatorID.IsValid() // no good.

I know args.IsValid works But I have no Args

I tried MyValidatorID.args.IsValid' is null or not an object

Thank you,


Teemu Keiski said:
Validation is initiated by calling Page_ClientValidate() or
Page_ClientValidate(group).

So maybe you could wire your own function to it - before calling to base
Page_ClientValidate set a flag to indicate that validation has initiated
and then in ValidatorSetFocus, when the flag is true (called the
ValidatorSetFocus for the first time) do what you need to do and set the
flag to false after that - e.g that logic runs only once and then in the
wired method - after the call to base.ClientValidate() - also set the flag
back to false.

It might also work that after call to wired Page_ClientValidate() (base
method), loop through Page_Validators array, and find the first failed
validator.

--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


IfThenElse said:
Hi Teemu,

Thank you for the
JavaScript-Function-Hijacking-delegating-hooking-intercepting trick.

I don't know what to call it you call it function pointer switching.
Nice.

This works for me as a second option. because if Microsoft changes the
name of the JavaScript functions that I am using then my code no longer
works.

Do you agree that the ValidatorSetFocus(val, event) is inefficient?
Since the focus should be on the First Validator that Fails, it seems
that it is Fired for every Failed Validator

Is there a function or can I do a switch at ValidationFinihed Event or
Function and get the First Validator That Failed Info?

Thank you for your valuable help.


Teemu Keiski said:
val.controltovalidate should return you the control which the validator
is validating.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Hi Teemu,

in the function function MyRequiredFieldValidatorIsValid(val)
{ .... } below

How do I get the current control or its Id that is being validated. or
the group_id from within the MyRequiredFieldValidatorIsValid(val)
function???

val mean Value but how about the control itself.

Thank you,


Hi,

In ASP.NEt 2.0 RequiredFieldValidatorIsValid is defined in System.Web
assembly's resources (WebUIValidation.js). it looks like:

function RequiredFieldValidatorEvaluateIsValid(val) {
return (ValidatorTrim(ValidatorGetValue(val.controltovalidate)) !=
ValidatorTrim(val.initialvalue))
}

You can do a function pointer switch in JavaScript. Basically first
create a member to point to the old function, then create your new
function which can use the previous member in case it needs to call
the default implementation/method. Then assign your new method to the
original function. In pseudo-code something like:

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

However in this case, in ASP.NEt 2.0, reference to the used function
is stored in as member of the validator element itself. If you check
the markup it can look like:

var ctl02 = document.all ? document.all["ctl02"] :
document.getElementById("ctl02");
ctl02.controltovalidate = "ddlAccomodationCountry";
ctl02.errormessage = "Make a selection";
ctl02.evaluationfunction = "RequiredFieldValidatorEvaluateIsValid";
ctl02.initialvalue = "0";

Note especially evaluationfunction attribute.

So just assigning

RequiredFieldValidator = MyRequiredFieldValidatorIsValid;

doesn't in fact seem to work. However you can write instead

<body onload="myLoad()">

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

******* complete test page *********

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body onload="myLoad()">
<form id="form1" runat="server">
<div>

<asp:DropDownList ID="ddlAccomodationCountry" runat="server">
<asp:ListItem Value="0" Text="Please make a selection" />
<asp:ListItem Value="1" Text="Country 1" />
<asp:ListItem Value="2" Text="Country 2" />
<asp:ListItem Value="3" Text="Country 3" />
</asp:DropDownList>

<asp:RequiredFieldValidator ControlToValidate="ddlAccomodationCountry"
InitialValue="0" runat="server" ErrorMessage="Make a selection" />

<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:ValidationSummary ID="ValidationSummary1" runat="server"
/>

</div>
</form>
<script type="text/javascript">

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

</script>
</body>
</html>

*** test page ends ***

Remember to always check Page.IsValid in server-side code too.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Hello,

I am wondering how can I Override/Append to the Client Side
JavaScript of a System.Web.UI.WebControls.RequiredFieldValidator
Control.

I actually need to only add few lines of JavaScript to the Microsoft
Supplied JavaScript Function.

So I need to Just extend it to do one or two extra things for me.

I know I can create a new Validation Control to do such thing but I
wonder If I can Inherit the exiting functionality.

If I inherit the "System.Web.UI.WebControls.RequiredFieldValidator"
How can I call the base class JavaScript that does the validation and
then add some more to it.

I have seen Scott Michell's "Creating Validator Controls for
CheckBox" etc... No inheritance because there was none. So the
example does not answer my needs.


thanks
Click to expand...
Click to expand...
Click to expand...
 
T

Teemu Keiski

In client-side DOM a validator has isvalid property (written literally in
lowercase)

--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


IfThenElse said:
Teemu,

I implemented the ValidatorSetFocus(val, event) Switch and that works.
However a bit of work.
For what I want that is better so far because it handles any validator (
not only required Field. etc.. )

I will look into the Page_ClientValidate Functions switch soon.

I was wondering, How do I ask a Validator if it is valid or not.

I tried something like MyValidatorID.IsValid but that did not work for me.
Got undefined error.

MyValidatorID.IsValid() // no good.

I know args.IsValid works But I have no Args

I tried MyValidatorID.args.IsValid' is null or not an object

Thank you,


Teemu Keiski said:
Validation is initiated by calling Page_ClientValidate() or
Page_ClientValidate(group).

So maybe you could wire your own function to it - before calling to base
Page_ClientValidate set a flag to indicate that validation has initiated
and then in ValidatorSetFocus, when the flag is true (called the
ValidatorSetFocus for the first time) do what you need to do and set the
flag to false after that - e.g that logic runs only once and then in the
wired method - after the call to base.ClientValidate() - also set the
flag back to false.

It might also work that after call to wired Page_ClientValidate() (base
method), loop through Page_Validators array, and find the first failed
validator.

--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


IfThenElse said:
Hi Teemu,

Thank you for the
JavaScript-Function-Hijacking-delegating-hooking-intercepting trick.

I don't know what to call it you call it function pointer switching.
Nice.

This works for me as a second option. because if Microsoft changes the
name of the JavaScript functions that I am using then my code no longer
works.

Do you agree that the ValidatorSetFocus(val, event) is inefficient?
Since the focus should be on the First Validator that Fails, it seems
that it is Fired for every Failed Validator

Is there a function or can I do a switch at ValidationFinihed Event or
Function and get the First Validator That Failed Info?

Thank you for your valuable help.


val.controltovalidate should return you the control which the validator
is validating.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Hi Teemu,

in the function function MyRequiredFieldValidatorIsValid(val)
{ .... } below

How do I get the current control or its Id that is being validated.
or the group_id from within the MyRequiredFieldValidatorIsValid(val)
function???

val mean Value but how about the control itself.

Thank you,


Hi,

In ASP.NEt 2.0 RequiredFieldValidatorIsValid is defined in System.Web
assembly's resources (WebUIValidation.js). it looks like:

function RequiredFieldValidatorEvaluateIsValid(val) {
return (ValidatorTrim(ValidatorGetValue(val.controltovalidate)) !=
ValidatorTrim(val.initialvalue))
}

You can do a function pointer switch in JavaScript. Basically first
create a member to point to the old function, then create your new
function which can use the previous member in case it needs to call
the default implementation/method. Then assign your new method to the
original function. In pseudo-code something like:

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

However in this case, in ASP.NEt 2.0, reference to the used function
is stored in as member of the validator element itself. If you check
the markup it can look like:

var ctl02 = document.all ? document.all["ctl02"] :
document.getElementById("ctl02");
ctl02.controltovalidate = "ddlAccomodationCountry";
ctl02.errormessage = "Make a selection";
ctl02.evaluationfunction = "RequiredFieldValidatorEvaluateIsValid";
ctl02.initialvalue = "0";

Note especially evaluationfunction attribute.

So just assigning

RequiredFieldValidator = MyRequiredFieldValidatorIsValid;

doesn't in fact seem to work. However you can write instead

<body onload="myLoad()">

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

******* complete test page *********

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body onload="myLoad()">
<form id="form1" runat="server">
<div>

<asp:DropDownList ID="ddlAccomodationCountry" runat="server">
<asp:ListItem Value="0" Text="Please make a selection" />
<asp:ListItem Value="1" Text="Country 1" />
<asp:ListItem Value="2" Text="Country 2" />
<asp:ListItem Value="3" Text="Country 3" />
</asp:DropDownList>

<asp:RequiredFieldValidator
ControlToValidate="ddlAccomodationCountry" InitialValue="0"
runat="server" ErrorMessage="Make a selection" />

<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:ValidationSummary ID="ValidationSummary1" runat="server"
/>

</div>
</form>
<script type="text/javascript">

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

</script>
</body>
</html>

*** test page ends ***

Remember to always check Page.IsValid in server-side code too.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Hello,

I am wondering how can I Override/Append to the Client Side
JavaScript of a System.Web.UI.WebControls.RequiredFieldValidator
Control.

I actually need to only add few lines of JavaScript to the Microsoft
Supplied JavaScript Function.

So I need to Just extend it to do one or two extra things for me.

I know I can create a new Validation Control to do such thing but I
wonder If I can Inherit the exiting functionality.

If I inherit the "System.Web.UI.WebControls.RequiredFieldValidator"
How can I call the base class JavaScript that does the validation
and then add some more to it.

I have seen Scott Michell's "Creating Validator Controls for
CheckBox" etc... No inheritance because there was none. So the
example does not answer my needs.


thanks
Click to expand...
Click to expand...
Click to expand...
 
I

IfThenElse

Teemu,

You are right. Thank you.

I can not find out how to Ask a validator to Validate. The "isvalid"
property is always ture.
what function to call to force a specific validator to validate.

Thanks again for all your help I am moving forward.


Teemu Keiski said:
In client-side DOM a validator has isvalid property (written literally in
lowercase)

--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


IfThenElse said:
Teemu,

I implemented the ValidatorSetFocus(val, event) Switch and that works.
However a bit of work.
For what I want that is better so far because it handles any validator
( not only required Field. etc.. )

I will look into the Page_ClientValidate Functions switch soon.

I was wondering, How do I ask a Validator if it is valid or not.

I tried something like MyValidatorID.IsValid but that did not work for
me. Got undefined error.

MyValidatorID.IsValid() // no good.

I know args.IsValid works But I have no Args

I tried MyValidatorID.args.IsValid' is null or not an object

Thank you,


Teemu Keiski said:
Validation is initiated by calling Page_ClientValidate() or
Page_ClientValidate(group).

So maybe you could wire your own function to it - before calling to base
Page_ClientValidate set a flag to indicate that validation has initiated
and then in ValidatorSetFocus, when the flag is true (called the
ValidatorSetFocus for the first time) do what you need to do and set the
flag to false after that - e.g that logic runs only once and then in the
wired method - after the call to base.ClientValidate() - also set the
flag back to false.

It might also work that after call to wired Page_ClientValidate() (base
method), loop through Page_Validators array, and find the first failed
validator.

--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Hi Teemu,

Thank you for the
JavaScript-Function-Hijacking-delegating-hooking-intercepting trick.

I don't know what to call it you call it function pointer switching.
Nice.

This works for me as a second option. because if Microsoft changes the
name of the JavaScript functions that I am using then my code no longer
works.

Do you agree that the ValidatorSetFocus(val, event) is inefficient?
Since the focus should be on the First Validator that Fails, it seems
that it is Fired for every Failed Validator

Is there a function or can I do a switch at ValidationFinihed Event or
Function and get the First Validator That Failed Info?

Thank you for your valuable help.


val.controltovalidate should return you the control which the
validator is validating.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Hi Teemu,

in the function function MyRequiredFieldValidatorIsValid(val)
{ .... } below

How do I get the current control or its Id that is being validated.
or the group_id from within the MyRequiredFieldValidatorIsValid(val)
function???

val mean Value but how about the control itself.

Thank you,


Hi,

In ASP.NEt 2.0 RequiredFieldValidatorIsValid is defined in
System.Web assembly's resources (WebUIValidation.js). it looks like:

function RequiredFieldValidatorEvaluateIsValid(val) {
return (ValidatorTrim(ValidatorGetValue(val.controltovalidate))
!= ValidatorTrim(val.initialvalue))
}

You can do a function pointer switch in JavaScript. Basically first
create a member to point to the old function, then create your new
function which can use the previous member in case it needs to call
the default implementation/method. Then assign your new method to
the original function. In pseudo-code something like:

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

However in this case, in ASP.NEt 2.0, reference to the used function
is stored in as member of the validator element itself. If you check
the markup it can look like:

var ctl02 = document.all ? document.all["ctl02"] :
document.getElementById("ctl02");
ctl02.controltovalidate = "ddlAccomodationCountry";
ctl02.errormessage = "Make a selection";
ctl02.evaluationfunction = "RequiredFieldValidatorEvaluateIsValid";
ctl02.initialvalue = "0";

Note especially evaluationfunction attribute.

So just assigning

RequiredFieldValidator = MyRequiredFieldValidatorIsValid;

doesn't in fact seem to work. However you can write instead

<body onload="myLoad()">

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

******* complete test page *********

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body onload="myLoad()">
<form id="form1" runat="server">
<div>

<asp:DropDownList ID="ddlAccomodationCountry" runat="server">
<asp:ListItem Value="0" Text="Please make a selection" />
<asp:ListItem Value="1" Text="Country 1" />
<asp:ListItem Value="2" Text="Country 2" />
<asp:ListItem Value="3" Text="Country 3" />
</asp:DropDownList>

<asp:RequiredFieldValidator
ControlToValidate="ddlAccomodationCountry" InitialValue="0"
runat="server" ErrorMessage="Make a selection" />

<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:ValidationSummary ID="ValidationSummary1" runat="server"
/>

</div>
</form>
<script type="text/javascript">

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

</script>
</body>
</html>

*** test page ends ***

Remember to always check Page.IsValid in server-side code too.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Hello,

I am wondering how can I Override/Append to the Client Side
JavaScript of a System.Web.UI.WebControls.RequiredFieldValidator
Control.

I actually need to only add few lines of JavaScript to the
Microsoft Supplied JavaScript Function.

So I need to Just extend it to do one or two extra things for me.

I know I can create a new Validation Control to do such thing but I
wonder If I can Inherit the exiting functionality.

If I inherit the "System.Web.UI.WebControls.RequiredFieldValidator"
How can I call the base class JavaScript that does the validation
and then add some more to it.

I have seen Scott Michell's "Creating Validator Controls for
CheckBox" etc... No inheritance because there was none. So the
example does not answer my needs.


thanks
Click to expand...
Click to expand...
Click to expand...
 
T

Teemu Keiski

There is ValidatorValidate function in ASPNET client-side validation
library.

var i;
for (i = 0; i < Page_Validators.length; i++) {
ValidatorValidate(Page_Validators, validationGroup, null);
}

--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net



IfThenElse said:
Teemu,

You are right. Thank you.

I can not find out how to Ask a validator to Validate. The "isvalid"
property is always ture.
what function to call to force a specific validator to validate.

Thanks again for all your help I am moving forward.


Teemu Keiski said:
In client-side DOM a validator has isvalid property (written literally in
lowercase)

--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


IfThenElse said:
Teemu,

I implemented the ValidatorSetFocus(val, event) Switch and that works.
However a bit of work.
For what I want that is better so far because it handles any validator
( not only required Field. etc.. )

I will look into the Page_ClientValidate Functions switch soon.

I was wondering, How do I ask a Validator if it is valid or not.

I tried something like MyValidatorID.IsValid but that did not work for
me. Got undefined error.

MyValidatorID.IsValid() // no good.

I know args.IsValid works But I have no Args

I tried MyValidatorID.args.IsValid' is null or not an object

Thank you,


Validation is initiated by calling Page_ClientValidate() or
Page_ClientValidate(group).

So maybe you could wire your own function to it - before calling to
base Page_ClientValidate set a flag to indicate that validation has
initiated and then in ValidatorSetFocus, when the flag is true (called
the ValidatorSetFocus for the first time) do what you need to do and
set the flag to false after that - e.g that logic runs only once and
then in the wired method - after the call to base.ClientValidate() -
also set the flag back to false.

It might also work that after call to wired Page_ClientValidate() (base
method), loop through Page_Validators array, and find the first failed
validator.

--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Hi Teemu,

Thank you for the
JavaScript-Function-Hijacking-delegating-hooking-intercepting trick.

I don't know what to call it you call it function pointer switching.
Nice.

This works for me as a second option. because if Microsoft changes
the name of the JavaScript functions that I am using then my code no
longer works.

Do you agree that the ValidatorSetFocus(val, event) is inefficient?
Since the focus should be on the First Validator that Fails, it seems
that it is Fired for every Failed Validator

Is there a function or can I do a switch at ValidationFinihed Event or
Function and get the First Validator That Failed Info?

Thank you for your valuable help.


val.controltovalidate should return you the control which the
validator is validating.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Hi Teemu,

in the function function MyRequiredFieldValidatorIsValid(val)
{ .... } below

How do I get the current control or its Id that is being validated.
or the group_id from within the
MyRequiredFieldValidatorIsValid(val)
function???

val mean Value but how about the control itself.

Thank you,


Hi,

In ASP.NEt 2.0 RequiredFieldValidatorIsValid is defined in
System.Web assembly's resources (WebUIValidation.js). it looks
like:

function RequiredFieldValidatorEvaluateIsValid(val) {
return (ValidatorTrim(ValidatorGetValue(val.controltovalidate))
!= ValidatorTrim(val.initialvalue))
}

You can do a function pointer switch in JavaScript. Basically first
create a member to point to the old function, then create your new
function which can use the previous member in case it needs to call
the default implementation/method. Then assign your new method to
the original function. In pseudo-code something like:

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

However in this case, in ASP.NEt 2.0, reference to the used
function is stored in as member of the validator element itself. If
you check the markup it can look like:

var ctl02 = document.all ? document.all["ctl02"] :
document.getElementById("ctl02");
ctl02.controltovalidate = "ddlAccomodationCountry";
ctl02.errormessage = "Make a selection";
ctl02.evaluationfunction = "RequiredFieldValidatorEvaluateIsValid";
ctl02.initialvalue = "0";

Note especially evaluationfunction attribute.

So just assigning

RequiredFieldValidator = MyRequiredFieldValidatorIsValid;

doesn't in fact seem to work. However you can write instead

<body onload="myLoad()">

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

******* complete test page *********

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body onload="myLoad()">
<form id="form1" runat="server">
<div>

<asp:DropDownList ID="ddlAccomodationCountry" runat="server">
<asp:ListItem Value="0" Text="Please make a selection" />
<asp:ListItem Value="1" Text="Country 1" />
<asp:ListItem Value="2" Text="Country 2" />
<asp:ListItem Value="3" Text="Country 3" />
</asp:DropDownList>

<asp:RequiredFieldValidator
ControlToValidate="ddlAccomodationCountry" InitialValue="0"
runat="server" ErrorMessage="Make a selection" />

<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:ValidationSummary ID="ValidationSummary1"
runat="server" />

</div>
</form>
<script type="text/javascript">

//Reference the original method
var fxRequiredFieldValidatorIsValid =
RequiredFieldValidatorEvaluateIsValid;

function MyRequiredFieldValidatorIsValid(val)
{
//Do your logic here (you can also do it after call to original
method, just note that you shoul return a boolean to indicate the
validation outcome)
alert("This should be called...")

//Use original method reference to call the original method
return fxRequiredFieldValidatorIsValid(val);
}

function myLoad()
{
for(var i = 0;i<Page_Validators.length;i++)
{
if(Page_Validators.evaluationfunction ==
fxRequiredFieldValidatorIsValid)
{
Page_Validators.evaluationfunction =
MyRequiredFieldValidatorIsValid;
}
}
}

</script>
</body>
</html>

*** test page ends ***

Remember to always check Page.IsValid in server-side code too.


--
Teemu Keiski
AspInsider, ASP.NET MVP
http://blogs.aspadvice.com/joteke
http://teemukeiski.net


Hello,

I am wondering how can I Override/Append to the Client Side
JavaScript of a System.Web.UI.WebControls.RequiredFieldValidator
Control.

I actually need to only add few lines of JavaScript to the
Microsoft Supplied JavaScript Function.

So I need to Just extend it to do one or two extra things for me.

I know I can create a new Validation Control to do such thing but
I wonder If I can Inherit the exiting functionality.

If I inherit the
"System.Web.UI.WebControls.RequiredFieldValidator" How can I call
the base class JavaScript that does the validation and then add
some more to it.

I have seen Scott Michell's "Creating Validator Controls for
CheckBox" etc... No inheritance because there was none. So the
example does not answer my needs.


thanks
Click to expand...
Click to expand...
Click to expand...
 

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