This is the documentation of JSU for Jira Server/Data Center. If you are using JSU on Jira Cloud, you can find the documentation here.
Description
The 'Clear Field Value' post-function clears the value of a specified field, after a transition has been completed.
Configuration
You must specify the field to be cleared. For example:
For information on how to configure a post-function in JIRA, see the JIRA documentation.
Precondition
There are several ways in which preconditions can be evaluated in the context of a post function: Ignore precondition (By default every precondition is ignored which means that the post function will be always performed) True (Precondition must be true to execute a post function) False (Precondition must be false to execute a post function) Learn more in Workflow preconditions.
Clear field on all issues related as
The field can be on the issue in transition(within same issue) or on a related issue, like a sub-task, a linked issue or an issue within an Epic (during the transition on the Epic).
See Related Issues for more explanation on this topic.
Perform As User
With Perform As User, you can specify a different user account that owns the necessary permissions. Usually, this user account is assumed to be only technical (impersonation), with broad permissions, but not used to log into a Jira account as a person. If you don't specify a user here, the transition on the related issue is performed as the same user who triggered this post function on the origin issue by default. Therefore that user must have the necessary permissions on the related issue. In some restrictive setups, that user might not have the permissions on the related issue or even might not have access to the project of the related issue. In combination with the 'User is in Any Users' Condition, you can hide a transition from all other users than the 'Perform As User' user.
Position of the Post Function
It is important to place the post function in the correct order of other post functions.
Create Transition
The 'Create' transition is the very fist transition, which does not yet has a source status (only destination status - usually Open, but could also be another).
Instead of using the "Clear Field Value" post function in the Create transition, you might consider to just configure no default value for that custom field and don't show it on the create screen.
If you are using the "Clear Field Value" post function in the Create transition, you must put it before the "Creates the issue originally" post function except when clearing labels, which need to be cleared after the issue has been created.
Any other Transition (not Create)
Put the "Clear Field Value" post function anywhere before the "Update change history for an issue and store the issue in the database." post function
Example
A workflow is configured so that the 'Close' transition has the 'Clear Field Value' post-function. The function is configured to clear the 'Security Level' field. If a user closes an issue on this workflow, the value of the 'Security Level' field will be cleared.
Supported Field Types
JSU supports many different field types such as system fields and custom fields. However you should be aware, that not all field types are supported, and not in all combinations. We aim to cover the most important field types and are continuously adding and improving how different field types are supported. Some custom fields of other third-party apps might never be supported.
For that reason, you should always test anything you do with the JSU app with fields. You can try it with a free 30-day evaluation license.