Trigger "change" event after updating user field input value

[ryandemmer]

Summary of Changes

The onchange event is not triggered on a form element when the element's value is updated programmatically, only on user input, therefore a "change" event must be dispatched when the user id field value is set.

Without dispatching a change event, the change event listener created for the data-onchange attribute is not triggered, and the associated function is not called.

Testing Instructions

Edit administrator/components/com_content/forms/article.xml and set an onchange attribute for the create_by field, eg:

<field 
    name="created_by" 
    type="user"
    label="COM_CONTENT_FIELD_CREATED_BY_LABEL"
    onchange="(function(){console.log('change')})()" 
/>

Create or edit an article, and in the Options tab, select a new user for the Created By field.

Expected result

In the browser console, "change" should be displayed when the new user is selected.

Actual result

Nothing is displayed in the console as a change event is not triggered.

Documentation Changes Required

None.

[ryandemmer]

Thank you @wilsonge !

[wilsonge]

Thankyou!

[ryandemmer]

This PR, although merged into 4.0-dev, does appear to have been dropped at some stage.

I would imagine this may have happened when the files were moved from media/system/webcomponents/js/ to media/system/js/fields/

The issue still exists, as you can see here - https://github.com/joomla/joomla-cms/tree/4.0-dev/media/system/js/fields/joomla-field-user.js

[brianteeman]

@ryandemmer please create a new issue and refer to this one - already merged and closed issues rarely get noticed. Thanks

[ryandemmer]

Done - #29404 - Thanks @brianteeman :)