Singleton Patterns, where do I put it?

[John Sheppard]

Hello,

I am working on a 3teired project, data,bizlogic, userinterface...I have a
global class that at current is being passed around as parameters, this is,
to say the least messy...

I am reading up about singletons, but I wonder where to place it? Should I
stick it in with the userinterface....how do I make it globally accessable
if its in a different layer/project...

Sorry if I sound like a noob, I am noob...
Thank you
John

 

[Cowboy \(Gregory A. Beamer\)]

If the singleton is used for UI bits, then the UI project (web project,
winforms project) is the correct place. The example here would be
application settings for the UI.

If not, then it does not belong there. It belongs in the layer where it is
used. If it is database settings, you can guess where it goes. If neither DB
nor UI, it is probably a business object. I say probably, as you may be
using a facade pattern and have it there (not as likely).

Short answer: Need to know more about what you are placing in the singleton
to answer more concretely.

--
Gregory A. Beamer
MVP, MCP: +I, SE, SD, DBA

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| Think outside the box!
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[John Sheppard]

I answered my own question...it works good!

I just put it in my Business Logic layer cause all lower layers use it...

Thanks for anyone who read my message...

 

[John Sheppard]

Thanks Cowboy...

Sorry my server was lagging at work and didnt see your response...

Im still learning about patterns, at current the singleton is the first
pattern im implementing...

At current it is a Business object so its going there...I know we have some
bad architecture issues which im working through, so its kinda half UI half
BO...but it will in the end be a BO layer...

Thanks once again, good answer, I very much appreciate it
John

 

[Cowboy \(Gregory A. Beamer\)]

If you want a decent enough, and cheap enough, set of patterns in a "real
world" application, consider looking at dofactory.com and purchasing the
Pattern Framework. I disagree with parts of the implementation, but it is a
great learning tool. It implements nearly every pattern, somewhere, and
illustrates the use of a facade between business and UI, which is rather
nice.

My biggest issue is with the implementation of the data layer, as I feel it
is a bit too complex for a maintainable solution, but it does work as a
basic pattern.

--
Gregory A. Beamer
MVP, MCP: +I, SE, SD, DBA

*************************************************
| Think outside the box!
|
*************************************************