JIRA allows you to perform additional tasks as part of a workflow transition through the use of post functions. JIRA makes heavy use of post functions internally, for example, with the out-of-the-box workflow, when you reopen an issue, the resolution field value is cleared automatically.

In this recipe, we will look at how to add post functions to a workflow transition. We will add a post function to automatically clear out the value stored in the Reason for Backlog custom field when we take it out of the Backlog status.