Context programming

I ll start this post with a phrase : WE HAVE TO REMEMBER TO NOT REINVENT THE WHEEL . Why I say that? XAF with the help of eXpand   is now a very mature framework. Almost all the tools required for build LOB applications are here. XAF has many ruling engines (Validation,EditorState,Appearence) and eXpand also the same ( AdditionalViewControls , ModelArtifactState , MasterDetail , ConditionalDetailViews). All the above engines provide a way to describe behaviors using rules and they operate over certain Contexts. What is a context some of you may ask. The answer is simple, context means the “when” the rule is going to be evaluated. For example Validation rules have 2 predefined contexts , those are Save,Delete. I am going to give an example of how powerful a context is . Let say we have a Customer-Order relationship and we have 2 cases like the following First record of Customer Orders cannot be deleted. Only the last record of Customer Orders can be deleted So what we need to design the above rules? First

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