Facts can be asserted to the BRE from .NET code simply by passing them as an argument to the policy’s execute method which takes a variable number of parameters.  For example,

Microsoft.RuleEngine.Policy policy = new Microsoft.RuleEngine.Policy(“PolicyName”);
Policy.Execute(Object1, Object2,…);

There are three types of facts used by the BRE:  An xml document, a Database table, and a .NET class.  The latter two have a couple peculiarities about them which require further explanation. 

Asserting a Database Table

When using a database table, the BRE expects an object of type Microsoft.RuleEngine.DataConnection to be asserted, which tells the BRE where to find the table.  This is achieved with the below code.

//Create the DataConnection
System.Data.SqlClient.SqlConnection connection = new System.Data.SqlClient.SqlConnection(“connectionstring”);
Microsoft.RuleEngine.DataConnection dconn = new Microsoft.RuleEngine.DataConnection(connection);

//Create the policy and assert the DataConnection
Microsoft.RuleEngine.Policy policy = new Microsoft.RuleEngine.Policy(“PolicyName”);
Policy.Execute(dconn);

Static .NET Methods

Calling a static .NET method from the BRE can be achieved without asserting an instance of the class by setting the the StaticSupport (DWORD value) registry key located under HKEY_LOCAL_MACHINE\Software\Microsoft\BusinessRules\3.0 to a value of 1.  Without this registry entry, static method calls within the BRE will require asserting instances of the class that contain the method.