AEM Library

Predicates

Predicates are typically used to filter collections; in the AEM Library, a Predicate can be used in ComponentNode and PageDecorator instances to filter lists of descendant nodes or pages using various criteria.

The library contains a few basic Predicate implementations, but predicates can also be implemented as anonymous inner classes or as static final instances (if they do not depend on instance variables, similar to a Comparator).

Using the Google Guava API, Predicates can easily be chained to build complex criteria to achieve more granular filtering behavior.

Predicate<ComponentNode> propertyExistsPredicate = new ComponentNodePropertyExistsPredicate("batman");
Predicate<ComponentNode> resourceTypePredicate = new ComponentNodeResourceTypePredicate("components/lo-pan");

Predicate<ComponentNode> predicate = Predicates.or(propertyExistsPredicate, resourceTypeExists);

List<ComponentNode> filteredComponentNodes = getComponentNodes(predicate);