CODEWITHSUNDEEP
c#mef
kubal5003
kubal5003

Reputation: 7254

MEF - use the same plugins several times

I've read MEF documentation on Codeplex and I'm trying to figure out how to accomplish my task:

I would like to build an application framework that has standard components that can be used to do some common work (like displaying a list of records from a database). Plugins should be reused many times with different configuration each time. (eg. I have 5 windows in an application where I display record lists, each with different type of entity, different columns, each one should have it's own extension points like for displaying record details that should be satisfied with a different copy of another common plugin).

Is MEF suitable for such a scenario? How should I define contracts? Should I use metadata? Can I define relationships using configuration files?

Upvotes: 0

Views: 213

Answers (1)

Dennis Smit
Dennis Smit

Reputation: 1188

Yes, you can use MEF. MEF supports NonShared instantiation of objects using the PartCreationPolicy attribute:

[PartCreationPolicy(CreationPolicy.NonShared)]

More information on this here.

Personally I'd do the wiring and configuration after the importing of the component on the target. However I am not sure how generic you want your application to be, if you are making a 'framework' to do certain solutions in I can imagine you want the configuration to be separate. You can go all-over-board and make an ISuperDuperGridConfiguration and import these on the constructor [ImportingConstructor] of your grid plugin. From within your target (where the grids get imported) set the location of the grid to the grid plugin (like main grid, side grid) and use the data stored in ISuperDuperGridConfiguration to further config the grid plugin itself.

However, you can easily go 'too far' with MEF, depending on your goals. We have a completely MEF componentized UI for an application with customized needs for every single customer. Sometimes I have the urge to put single buttons from the ribbon in a MEF extension.

As you can see, depending on your needs, you can and sometimes will go too far.

I don't think you'd need metadata especially in your case, but maybe someone else can share a different opinion on this ;-).

I hope this answers your question, if not please comment so I can highlight more aspects. All in all using MEF has been very positive for us, and we are using it far beyond a 'hello world' so to say. So at least you have that!

Upvotes: 2

Related Questions