PTC Arbortext Publishing Engine Programmer's Guide (PTC Arbortext Publishing Engine 程式設計師指南) > The Arbortext Publishing Engine Request Manager > Predefined Dynamic Components > Predefined Request Selectors
  
Predefined Request Selectors
Request selectors are referenced by the TestSet of a SubprocessPool to determine if an Arbortext PE 子流程 pool should service a request. They can be grouped by And and Or elements within a TestSet to set up more complex acceptance criteria.
Individual Request Selectors are invoked when a Arbortext PE 子流程 pool evaluates a call to its testRequest method to determine whether its Arbortext PE 子流程 should be allocated to a particular HTTP request. testRequest is normally called by the Arbortext Publishing Engine Request Context as part of evaluating its allocateE3Subprocess method.