The Option filtering delegate filters occurrences in the part structure tree and in the Occurrences table.

You can assign basic or advanced expressions to an occurrence. The logic for filtering occurrences is the same as for filtering usage links. The only difference is that when filtering usage links, the system combines expressions assigned to the usage link with those assigned to the child part. When filtering occurrences, the Option filter relies only on the expressions assigned to the occurrence.

Companies can configure the standard and alternate filtering behavior for occurrences. In particular, you can define certain special filtering policies for occurrences.

The out-of-the-box behavior filters out the occurrences if the advanced expression evaluates to False (or if a basic expression cannot be matched against the choices selected in the filter).

The out-of-the-box alternate behavior filters out the occurrence if one of these conditions is true:

A filtering policy for occurrences can be defined within the FilterNode tag as follows:

The “parentType” and “childType” of the FilterNode element refer to the type of the parent part and the type of the resolved child part of the usage link for which the occurrence is defined.

For example, to apply the out-of-the-box alternate filtering logic for occurrences whose usage link connects parts of types ABCPart and CBSPart, define the following policy:

You can also describe the occurrences to be filtered if they are missing an expression. The meaning of the attributes “type”, “partType” and “childType” of the “FilterMissingExpression”, are the same as those of the “FilterNode” element. For example, the following policy specifies that occurrences whose usage link connects the parts of types ABCPart and CBSPart will be filtered out if they do not have an expression assigned:

Note that an occurrence is subordinate to its usage link—it exists only in the context of its usage link. Therefore, an occurrence of a given usage link is filtered by the Option filtering delegate only after its usage link has been examined by the Option filtering delegate and has been retained in the filtering process. If all occurrences of a usage link are filtered out, this also filters out the usage links. As a result, all corresponding usage links and occurrence nodes are removed from the part structure tree.