This type of read-only custom field has a value which is dynamically calculated from a custom text expression. It can be used to show a text composed from one or more field values.
You can also create any custom text value depending on the values of other fields in current issue, linked issues, sub-tasks, epics, stories, or any other issue in your Jira instance selected by a JQL query.
There 2 parsing modes available:
This parameter contains the text expression that will be parsed in the selected parsing mode.
In this example we show how to create a calculated text field called "Components of Subtasks" that will contain a comma separated list with the components of current issue's sub-tasks.
1) Create a new Calculated Text Field custom field called "Components of Sub-tasks" at Administration > Issues > Custom fields > Add Custom Field > Advanced > Calculated Text Field (by JWT)
2) Go to configuration screen of the newly created custom field:
3) Click on 'Edit Text Expression':
4) Configure the field by selecting a parsing mode, and by entering a text to be parsed:
5) Once configured, the configuration of the new custom field looks like this:
The text expression used in this example is: toString(distinct(fieldValue(%{00094}, subtasks())))
, where %{00094} is field code for Components.