What is fact ?
Facts are discrete pieces of information about the world. Facts can originate from many sources
Facts are discrete pieces of information about the world. Facts can originate from many sources (event systems, objects in business applications, database tables, and so on), and must be fed into the Business Rule engine in BizTalk Server by using one of the following elements:
Fact types.
.Net objects
In the Business Rule Composer, you can specify a .NET assembly as a data source
Engine control functions
This Engine control functions are allow the application or policy to control the facts in the rule engine's working memory.
Engine controlf functions are
Assert
Retract
RetractByType
Reassert
Update
Halt
Assert
Assertion is the process of adding object isntances into Business Rule engine's working memory.
The following table summarizes the assert behavior for the various types, showing the number of resulting instances created in the engine for each asserted entity, as well as the type that is applied to each of those instances to identify them.
Retract:
You can use the Retract funciton to remove objects form the Business rule engine's working copy.
RetractByType
The RetractByType funciton retracts all instances of a specified type in the working memory, where as the Retract function retracts only specific items of a certain type.
Reassert
To reassert means to call the Assert function on an object that is already in the engine's working memory.
Update
When Update function is invoked an object, the object is reasserted into the engine to be re-evaluated, based on the new data and state.
Halt
You can use the Halt function to halt the current rule engine execution. The Halt function takes one parameter of type Boolean. If you specify the value for the parameter as true, the rule engine also clears the agenda that contains the pending candidate rules.
http://en.wikipedia.org/wiki/Rete_algorithm
Facts are discrete pieces of information about the world. Facts can originate from many sources
Facts are discrete pieces of information about the world. Facts can originate from many sources (event systems, objects in business applications, database tables, and so on), and must be fed into the Business Rule engine in BizTalk Server by using one of the following elements:
Fact types.
- .NET objects (methods, properties, and fields)
- XML documents (elements, attributes, and document subsections)
- Database rowsets (values from table column)
.Net objects
In the Business Rule Composer, you can specify a .NET assembly as a data source
Engine control functions
This Engine control functions are allow the application or policy to control the facts in the rule engine's working memory.
Engine controlf functions are
Assert
Retract
RetractByType
Reassert
Update
Halt
Assert
Assertion is the process of adding object isntances into Business Rule engine's working memory.
The following table summarizes the assert behavior for the various types, showing the number of resulting instances created in the engine for each asserted entity, as well as the type that is applied to each of those instances to identify them.
| Entity | Number of instances asserted | Instance type |
|---|---|---|
| .NET object | 1 (the object itself) | Fully Qualified .NET Class |
| TypedXmlDocument | 1-N TypedXmlDocument(s): Based on Selector bindings created and document content | DocumentType.Selector |
| TypedDataTable | 1-N TypedDataRow(s): One for each DataRow in the DataTable | DataSetName.DataTableName |
| TypedDataRow | 1 (the TypedDataRow asserted) | DataSetName.DataTableName |
| DataConnection | 1-N (one for each TypedDataRow returned by querying the DataConnection) | DataSetName.DataTableName |
Retract:
You can use the Retract funciton to remove objects form the Business rule engine's working copy.
RetractByType
The RetractByType funciton retracts all instances of a specified type in the working memory, where as the Retract function retracts only specific items of a certain type.
Reassert
To reassert means to call the Assert function on an object that is already in the engine's working memory.
Update
When Update function is invoked an object, the object is reasserted into the engine to be re-evaluated, based on the new data and state.
Halt
You can use the Halt function to halt the current rule engine execution. The Halt function takes one parameter of type Boolean. If you specify the value for the parameter as true, the rule engine also clears the agenda that contains the pending candidate rules.
http://en.wikipedia.org/wiki/Rete_algorithm
