Transaction Filters

A transaction filter is a user-defined function that gets executed whenever certain Content Engine operations (or transactions) are performed, and can thereby modify the outcome of those operations. The transactions that can be modified in this way are:

  • Object creation

  • Object update

  • Object deletion

A transaction filter is implemented as a Java class. It is in many ways similar to an event listener (see Event Listeners). However, where an event listener performs an operation immediately after some Content Engine operation has been carried out, a transaction filter is executed during the operation itself. A transaction filter can, for example:

  • Modify the content of a content item as it is being saved

  • Prevent a content item from being deleted unless certain criteria are met