How does the user picker work in Jira applications

Summary

JIRA applications use the user picker for the assignee and reporter field, as well as custom user or group picker field. With AJAX, the user picker will return possible results on each entry. However, there is no documentation on how it works from the background.

Solution

How does the Jira application user picker work?

• The user picker first figures out the group via Project -> Role -> Group (i.e. determines that the assignable users for project X are the users in role Y, and therefore the users in group Z).

• This fires a REST call on every keystroke, depending on how fast the characters are entered.

• It uses the configured User Directories (AD, Crowd...) to get a list of users that belong to group Z.

• Matches the entered characters with the username, email address, and display name.

• The User Picker's auto-suggest feature requires the Browse User's Global Permissions to work. Without this permission, users would only be able to specifically add exact usernames.

Can you change the REST call interval?

Unfortunately no. It will do a request 75 millisecond after entering a character. If the user enters another character in that 75ms period, it will restart the timer. In other words, if the user types the name really fast, it won't do a search until the full name has been entered. A way to force that behavior is to write the username somewhere else, and copy and paste it into the field: that will result in just one REST call.

Will the way that the user picker works cause performance issues?

It's possible that this could cause performance problems in some particular circumstances. There are two potential problems:

• If the user has multiple User Directories, searching for the members of a group could be slow.

Solution: Reduce the number of User Directories and/or move the User Directory containing the requested group to the top of the preference chain.

• If the project has a very broad assignable group (for example, all the users in a Jira application are potentially assignable, but only a few of them are actually assigned), retrieving the list of users and matching the characters could be expensive.

Solution: Create a smaller assignable group. It is better to add users when needed than to add lots of Jira application users who never get an issue assigned.