Dynamic Business Rules

I am creating an interface where users can build their own business rules out of domain specific objects at runtime, have those rules persisted 开发者_运维知识库in the database and then used by the application. Some of these are complex predicates and others require combinations of domain objects in what seems fairly complicated relations. So far I have looked into GoF, dynamics with eval, and CodeDom. Does anyone have suggestion on what should be used?

Actually, you can just develop your application with WF rules engine API without using WF. http://blogs.microsoft.co.il/blogs/bursteg/archive/2007/08/09/WF-Rules-Engine-without-Workflow.aspx This will save you from a lot of work.

Kaizen, depending on the scope and kind of your dynamic rules you could eventually use a workflow engine, like MS WF to define the rules as workflow activities for example... in this way you isolate the logic and do not need a full rebuild of the application when you need to change anything in the workflow.

This might not be the best solution but could be an alternative...

Having spent a year building a rules engine and fighting on approaches I can tell you its not easy. Especially when you focus on what your goal is. If its to get users to write the rules for the system, you really need to focus hard on that area. Whats easy for a developer is perhaps much harder for most business users. We built a rules authoring platform in Excel that was compiled into C# and run dynamically ... problem was users found the spreadsheets and flow of logic too complicated and hired ASp.NET contractors to do build the rules.

BizTalk has an engine that I believe can be used for .NEt apps http://www.microsoft.com/biztalk/en/us/business-rule-framework.aspx

Have fun!

How often do the rules change? Building a system that let's the business build (and version) their own rules is significantly more challenging than building a system that lets a programmer update the rules dynamically.

When a similar requirement came up in a past project, the business admitted that while yes, the rules will change; they won't change so often that it has to be them making the updates. We ended up using IronPython for the dynamic parts and storing the code in the database and the system would pull up the appropriate rules on load. The rest of the app was written in C#. A win for us and for the business.