About the Knowledge Pattern Feature

You can create a pattern by clicking Knowledge Pattern .

The objects that are supported by this feature are:

• User features
• Datums (points, lines, curves, circles, surfaces, planes, volumes, axis systems).

The knowledge pattern is very similar to the action feature. Like the action feature, it contains an expressional part that allows you to specify what actions you want to perform usually using loops and the for keyword. The main differences between both features are the following:

• When creating a knowledge pattern, you can create lists that are aggregated to knowledge pattern features. These lists contain links to the created objects, and the knowledge pattern feature controls the lifecycle of the created objects through the content of these lists.
  Note: It can be useful to create several lists to handle different kind of objects. It provides an easy access to the results that have different semantics.
• You can use methods available in the dictionary to manage the instantiation and the modification of 3D templates, and to create or modify datum objects.
• You can specify the update behavior of the knowledge pattern feature:
  • Automatic update before the document root feature ( part, product, …) update
  • Manual update
  • Object update (the pattern can be updated through a reaction: In this case, make sure that you do not select the Automatic update mode).
• You can specify what happens if the controlled objects are pointed to by other objects when the pattern is executed another time.

Specific functions let you manipulate knowledge patterns.

The knowledge pattern allows the conditional instantiation of a template or another depending on some specifications (if … then instantiate A else instantiate B). The index in knowledge pattern lists enables you to identify the template. If a call is made to instantiate with index i in list L, the application looks for an instance in the list at this position.

• If no instance is found, an instance is created and inserted into the list L at the position i.
• If an instance is found, the application compares the identifier given as first argument with the one that was used for the previous instance. If this identifier is different, the system instantiates the new template and replaces the previous instance with a new one. This replace operation reroutes links from the old instance to the new one. Naming is copied from the previous instance.

To know more about these functions, see the generative function package documentation in the Enterprise Knowledge Language Reference Guide.

The knowledge pattern ensures the associativity of created objects.

This associativity is ensured with respect to:

• The parameters values of these objects. As an example, the templates publish parameters and a value change can impact the geometry of the instances.
• The number of objects to generate.
• The templates themselves. Depending on some expressional conditions or input changes, the templates to instantiate can change.
• The inputs of the expressional object defining the Knowledge pattern.
• The inputs of these objects. The inputs can be geometric inputs or parametric ones. The inputs of the expression are the objects that are not used as l-values (that are not specified by an affectation operation).

To manage associativity, the knowledge pattern uses:

• The Enterprise Knowledge Language (EKL) that contains loop structures and conditional expressions and that allows instantiating and modifying templates. It also allows the instantiation of datums and templates and the modification of created instances using the Generative Knowledge functions.
• Lists that contain all objects and identify them in a unique way. These lists contain the knowledge pattern instantiated objects. They are published, enabling you to access the objects in other expressional objects. The knowledge pattern feature controls the lifecycle of the objects grouped in these lists.

The List features is aggregated under the knowledge pattern feature (including the list containing locked objects).

This command allows locking generated objects.

The knowledge pattern feature lets you lock the generated objects so that further executions cannot modify them. There are two ways to lock these objects:

• By manually adding or removing the generated object from the LockedInstances list from the pattern.
• Use the dedicated function added to the Enterprise Knowledge Language (EKL) to perform this action.

When executing the knowledge pattern, you cannot modify nor delete the locked objects even if:

• You use the Generative Knowledge functions and if the arguments change.
• You re-execute the pattern without calling the CreateOrModify function for this object.
• You use affectation operators when creating datums.
• You try to write object attributes (except if you use the SetAttribute.xxx methods).