cyclic dependency

[Pohihihi]

This is a report from VSS newsgroup in hope of getting some more suggestions.

Thanks,
Po

-------------------------------------------
I guess I am not getting the whole picture here. How does this apply to the
condition when there is a cyclic reference for the binaries (dlls) in dotNet
!!
What I am thinking is that to use the real ProjectB object I will still need
to create a object from ProjectB for mapping in ProjectA, which again puts
me in loop.

Two interfaces can be made for 2 different project but still for mapping
unless I use dynamic assmebly invoke I do not see how we can do somethng
like following ---

// 1st physical binary (MyProject.Home.dll
namespace MyProject.Home
{
public class ProjectA: System.Windows.Forms.Form
{
public ProjectA()
{ // create object to use later}

public void MyProjA_Method()
{ // do something }

public void MyProjAMethodCallsProjBMethod()
{
int i = (new ProjectB()).CalBalls(5);
}
}
}

//2nd physical binary (MyProject.Work.dll
namespace MyProject.Work
{
public class ProjectB: System.Windows.Forms.Form
{
public void MyMethodInB()
{
ProjectA pA = new ProjectA();
pA.Show();
}

public int CalBalls(int i)
{// return some calculation as int}
}
}

Pohihihi,
Normally when I have two projects that need to refer to each other I use a
Separated Interface Pattern.

http://www.martinfowler.com/eaaCatalog/separatedInterface.html

Depending on the needs of the solution will decide if I use 2 or 3
projects
to implement the Separated Interface Pattern.

The "easiest" way is to put the interfaces in the first project, then
reference the first project from the second. Alternatively you can put the
interfaces in a project by themselves, and reference the interface project
from both of the other projects.

Something like:

' Project A

Public Interface InterfaceA
Sub SomeMethod()
End Interface

Public Class Something

Sub DoSomething(anA As InterfaceA)
anA.SomeMethod()
End Sub

End Class

' Project B
' references Project A

Public Class SomethingElse
Implements InterfaceA

Sub DoSomething()
Dim something As New Something
something.DoSomething(Me)
End Sub

Sub SomeMethod() Implements InterfaceA.SomeMethod
...
End Sub

End Class

--
Hope this helps
Jay [MVP - Outlook]
.NET Application Architect, Enthusiast, & Evangelist
T.S. Bradley - http://www.tsbradley.net


Hello,

I have 2 project A & B belonging to same solution. Now what I want is that
few forms I am accessing from A in B and few I am doing that other way
around. What should I do to not get the error while building solution, I
mean by the build sequencing.

Thanks,
Po

 

[Nicholas Paldino [.NET/C# MVP]]

Po,

Forgive me for saying so, but I see cyclical references between
assemblies as a sign of bad design. If they really have a need to have that
level of familiarity with each other, then I don't see why they can't be in
the same assembly.

If you really need this, the only way to do it is the way that Jay
suggested, using interfaces. Otherwise, you will have to place the classes
in the same assembly.

On top of that, I don't think that you will find circular references in
..NET anytime soon. I think it was considered at one point, but shot down
pretty quickly.

Hope this helps.


--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)

This is a report from VSS newsgroup in hope of getting some more
suggestions.

Thanks,
Po

-------------------------------------------
I guess I am not getting the whole picture here. How does this apply to the
condition when there is a cyclic reference for the binaries (dlls) in dotNet
!!
What I am thinking is that to use the real ProjectB object I will still need
to create a object from ProjectB for mapping in ProjectA, which again puts
me in loop.

Two interfaces can be made for 2 different project but still for mapping
unless I use dynamic assmebly invoke I do not see how we can do somethng
like following ---

// 1st physical binary (MyProject.Home.dll
namespace MyProject.Home
{
public class ProjectA: System.Windows.Forms.Form
{
public ProjectA()
{ // create object to use later}

public void MyProjA_Method()
{ // do something }

public void MyProjAMethodCallsProjBMethod()
{
int i = (new ProjectB()).CalBalls(5);
}
}
}

//2nd physical binary (MyProject.Work.dll
namespace MyProject.Work
{
public class ProjectB: System.Windows.Forms.Form
{
public void MyMethodInB()
{
ProjectA pA = new ProjectA();
pA.Show();
}

public int CalBalls(int i)
{// return some calculation as int}
}
}

Pohihihi,
Normally when I have two projects that need to refer to each other I use a
Separated Interface Pattern.

http://www.martinfowler.com/eaaCatalog/separatedInterface.html

Depending on the needs of the solution will decide if I use 2 or 3
projects
to implement the Separated Interface Pattern.

The "easiest" way is to put the interfaces in the first project, then
reference the first project from the second. Alternatively you can put the
interfaces in a project by themselves, and reference the interface project
from both of the other projects.

Something like:

' Project A

Public Interface InterfaceA
Sub SomeMethod()
End Interface

Public Class Something

Sub DoSomething(anA As InterfaceA)
anA.SomeMethod()
End Sub

End Class

' Project B
' references Project A

Public Class SomethingElse
Implements InterfaceA

Sub DoSomething()
Dim something As New Something
something.DoSomething(Me)
End Sub

Sub SomeMethod() Implements InterfaceA.SomeMethod
...
End Sub

End Class

--
Hope this helps
Jay [MVP - Outlook]
.NET Application Architect, Enthusiast, & Evangelist
T.S. Bradley - http://www.tsbradley.net


Hello,

I have 2 project A & B belonging to same solution. Now what I want is that
few forms I am accessing from A in B and few I am doing that other way
around. What should I do to not get the error while building solution, I
mean by the build sequencing.

Thanks,
Po

 

[Pohihihi]

Nicholas,

Yes, I agree, but we are limited to what is giving as other team do not
agree to change anything other than adding one line for our part. Only thing
I wish is that managers would understand more of the programming than
deadlines.

Thanks.

Po,

Forgive me for saying so, but I see cyclical references between
assemblies as a sign of bad design. If they really have a need to have
that level of familiarity with each other, then I don't see why they can't
be in the same assembly.

If you really need this, the only way to do it is the way that Jay
suggested, using interfaces. Otherwise, you will have to place the
classes in the same assembly.

On top of that, I don't think that you will find circular references in
.NET anytime soon. I think it was considered at one point, but shot down
pretty quickly.

Hope this helps.


--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)

This is a report from VSS newsgroup in hope of getting some more
suggestions.

Thanks,
Po

-------------------------------------------
I guess I am not getting the whole picture here. How does this apply to
the
condition when there is a cyclic reference for the binaries (dlls) in
dotNet
!!
What I am thinking is that to use the real ProjectB object I will still
need
to create a object from ProjectB for mapping in ProjectA, which again puts
me in loop.

Two interfaces can be made for 2 different project but still for mapping
unless I use dynamic assmebly invoke I do not see how we can do somethng
like following ---

// 1st physical binary (MyProject.Home.dll
namespace MyProject.Home
{
public class ProjectA: System.Windows.Forms.Form
{
public ProjectA()
{ // create object to use later}

public void MyProjA_Method()
{ // do something }

public void MyProjAMethodCallsProjBMethod()
{
int i = (new ProjectB()).CalBalls(5);
}
}
}

//2nd physical binary (MyProject.Work.dll
namespace MyProject.Work
{
public class ProjectB: System.Windows.Forms.Form
{
public void MyMethodInB()
{
ProjectA pA = new ProjectA();
pA.Show();
}

public int CalBalls(int i)
{// return some calculation as int}
}
}

Pohihihi,
Normally when I have two projects that need to refer to each other I use
a
Separated Interface Pattern.

http://www.martinfowler.com/eaaCatalog/separatedInterface.html

Depending on the needs of the solution will decide if I use 2 or 3
projects
to implement the Separated Interface Pattern.

The "easiest" way is to put the interfaces in the first project, then
reference the first project from the second. Alternatively you can put
the
interfaces in a project by themselves, and reference the interface
project
from both of the other projects.

Something like:

' Project A

Public Interface InterfaceA
Sub SomeMethod()
End Interface

Public Class Something

Sub DoSomething(anA As InterfaceA)
anA.SomeMethod()
End Sub

End Class

' Project B
' references Project A

Public Class SomethingElse
Implements InterfaceA

Sub DoSomething()
Dim something As New Something
something.DoSomething(Me)
End Sub

Sub SomeMethod() Implements InterfaceA.SomeMethod
...
End Sub

End Class

--
Hope this helps
Jay [MVP - Outlook]
.NET Application Architect, Enthusiast, & Evangelist
T.S. Bradley - http://www.tsbradley.net


Hello,

I have 2 project A & B belonging to same solution. Now what I want is
that
few forms I am accessing from A in B and few I am doing that other way
around. What should I do to not get the error while building solution, I
mean by the build sequencing.

Thanks,
Po

 

[Guest]

I also have a problem with circular dependancy which I would like some advice
about. I have to say I don't understand the reasoning behins this circular
dependancy rule at all. In the old days you could have two classes that
refered to each other and the linker never complained, what's the difference?
Anyway, I have a perfectly reasonable situation, I have a configuration
class that contains information about my system generally, and I have an
event logging class that writes events to a file. They are in separate
assemblies, which seems reasonable. The configuration class contains a log
file retention period which the event logger needs. However the configuration
class also needs to log events. Can't be done. Now, I could put both classes
in the same assembly. In fact I could put all my classes into one great big
assembly, but surely that is not the way. What is the answer?
--
Dave

Po,

Forgive me for saying so, but I see cyclical references between
assemblies as a sign of bad design. If they really have a need to have that
level of familiarity with each other, then I don't see why they can't be in
the same assembly.

If you really need this, the only way to do it is the way that Jay
suggested, using interfaces. Otherwise, you will have to place the classes
in the same assembly.

On top of that, I don't think that you will find circular references in
..NET anytime soon. I think it was considered at one point, but shot down
pretty quickly.

Hope this helps.


--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)

This is a report from VSS newsgroup in hope of getting some more
suggestions.

Thanks,
Po

-------------------------------------------
I guess I am not getting the whole picture here. How does this apply to the
condition when there is a cyclic reference for the binaries (dlls) in dotNet
!!
What I am thinking is that to use the real ProjectB object I will still need
to create a object from ProjectB for mapping in ProjectA, which again puts
me in loop.

Two interfaces can be made for 2 different project but still for mapping
unless I use dynamic assmebly invoke I do not see how we can do somethng
like following ---

// 1st physical binary (MyProject.Home.dll
namespace MyProject.Home
{
public class ProjectA: System.Windows.Forms.Form
{
public ProjectA()
{ // create object to use later}

public void MyProjA_Method()
{ // do something }

public void MyProjAMethodCallsProjBMethod()
{
int i = (new ProjectB()).CalBalls(5);
}
}
}

//2nd physical binary (MyProject.Work.dll
namespace MyProject.Work
{
public class ProjectB: System.Windows.Forms.Form
{
public void MyMethodInB()
{
ProjectA pA = new ProjectA();
pA.Show();
}

public int CalBalls(int i)
{// return some calculation as int}
}
}

Pohihihi,
Normally when I have two projects that need to refer to each other I use a
Separated Interface Pattern.

http://www.martinfowler.com/eaaCatalog/separatedInterface.html

Depending on the needs of the solution will decide if I use 2 or 3
projects
to implement the Separated Interface Pattern.

The "easiest" way is to put the interfaces in the first project, then
reference the first project from the second. Alternatively you can put the
interfaces in a project by themselves, and reference the interface project
from both of the other projects.

Something like:

' Project A

Public Interface InterfaceA
Sub SomeMethod()
End Interface

Public Class Something

Sub DoSomething(anA As InterfaceA)
anA.SomeMethod()
End Sub

End Class

' Project B
' references Project A

Public Class SomethingElse
Implements InterfaceA

Sub DoSomething()
Dim something As New Something
something.DoSomething(Me)
End Sub

Sub SomeMethod() Implements InterfaceA.SomeMethod
...
End Sub

End Class

--
Hope this helps
Jay [MVP - Outlook]
.NET Application Architect, Enthusiast, & Evangelist
T.S. Bradley - http://www.tsbradley.net


Hello,

I have 2 project A & B belonging to same solution. Now what I want is that
few forms I am accessing from A in B and few I am doing that other way
around. What should I do to not get the error while building solution, I
mean by the build sequencing.

Thanks,
Po