Working with the Reaction Feature

The reaction is a feature that reacts to events on its source(s) by triggering an action. It is designed to cope with the rules and the behaviors limitations and to create more associative and reactive design.

A reaction is a feature that reacts to events

The source can be:

	A selected feature (or a list of features)
	A parameter (result of a test)

Events can be:

	General events on objects (creation, deletion, update, drag and drop, attribute changes) and parameter value changes.
	Specific events such as a power copy or a UDF instantiation/update.
	Insert/Replace component
	Object Drag and Drop

A reaction is similar to a rule in the fact that:

	It is stored in the model.
	It reacts to changes and can trigger modifications.
	It also references other objects and parameters in the document and supports the replace mechanism.

But

	Reaction features provide a better control over when the action has to be fired.
	Reactions enable the user to perform more complex actions. Since you have better control when the action is triggered, and as you're not constrained by the update mechanism limitations, you can use all the power of any Visual Basic API (in CATIA but also in other automation applications...), and a Visual Basic macro can be called with arguments from an action.
	Reactions can be written to customize the update mechanism (to optimize user features, for example).
	Reactions can react to user actions (instantiation of a user defined feature), insertion of a component in an assembly, modification of a parameter...
	Reactions can be stored in the model and can be integrated in the definition of a power copy or user feature.

Using the Reaction Feature Window