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.
By default, JIRA comes with a post function that can change the values for standard issue fields, but since Reason for Backlog is a custom field, we need to have the JIRA Suite Utilities add-on installed.
You can download it from the following link or install it directly using the Universal Plugin Manager:
https://marketplace.atlassian.com/plugins/com.googlecode.jira-suite-utilities