I've just run into the same need for a well-defined interface that when implemented by a module's business controller class would allow a module instance to perform database cleanup at the time a module (or page containing the module) is deleted from the recycle bin.  I'm developing a prayer request and update module for church websites - it's much like a specialized forum - that creates entries in 9 tables plus makes entries to the ModuleSettings and UserProfile tables. Different groups/ministries in the church will be able to place distinct instances of the module on their own page(s). As groups/ministries come and go, I forsee that that instances of this module or pages on which it was placed will be frequently created then later deleted leaving considerable garbage in the various tables. Although I will provide the usual SQL uninstall stript to be run when the module definition is deleted, I don't see any way to trigger cleanup of associated table data (keyed to ModuleId at its top level) when a module instance is deleted.  For now I will probably have to implement a manually triggered cleanup in an associated administration module.

I vote for the addition of an IDisposable (or whatever it will be called) interface to be defined in the core, much like IPortable, ISearchable, etc.

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Bill, WESNet Designs
Team Lead - DotNetNuke Gallery Module Project (Not Actively Being Developed)
Extensions Forge Projects . . .
Current: UserExport, ContentDeJour, ePrayer, DNN NewsTicker, By Invitation
Coming Soon: FRBO-For Rent By Owner

Thanks Phil . . . the light comes on! I knew that the delete of a module from the Modules table could cascade to my custom top level table but had forgotten that with proper foreign key relationships AND with cascade deletes properly enabled, the deletion could then cascade to other related tables.  I'll need to work on the foreign key relationships a bit more and may have to add a ModuleId column to a couple of lookup tables. Thanks again.

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Bill, WESNet Designs
Team Lead - DotNetNuke Gallery Module Project (Not Actively Being Developed)
Extensions Forge Projects . . .
Current: UserExport, ContentDeJour, ePrayer, DNN NewsTicker, By Invitation
Coming Soon: FRBO-For Rent By Owner

Although in general, it is very easy to add a foreign key with cascade deleting in sql, one of the rather big problems is that if something ever changes in the modules table (ie, a change in the definition of the table), your module might break. Using a trigger might be safer..

books online will tell you something more about cascading delete constraints: http://msdn2.microsoft.com/en-us/library/ms188066.aspx

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Erik van Ballegoij, Former DNN Corp. Employee and DNN Expert

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