JavaScript customizations in the admin

Inline form events

You may want to execute some JavaScript when an inline form is added or removed in the admin change form. The formset:added and formset:removed jQuery events allow this. The event handler is passed three arguments:

• event is the jQuery event.
• $row is the newly added (or removed) row.
• formsetName is the formset the row belongs to.

The event is fired using the django.jQuery namespace.

In your custom change_form.html template, extend the admin_change_form_document_ready block and add the event listener code:

{% extends 'admin/change_form.html' %}
{% load static %}

{% block admin_change_form_document_ready %}
{{ block.super }}
<script src="{% static 'app/formset_handlers.js' %}"></script>
{% endblock %}

(function($) {
    $(document).on('formset:added', function(event, $row, formsetName) {
        if (formsetName == 'author_set') {
            // Do something
        }
    });

    $(document).on('formset:removed', function(event, $row, formsetName) {
        // Row removed
    });
})(django.jQuery);

Two points to keep in mind:

• The JavaScript code must go in a template block if you are inheriting admin/change_form.html or it won’t be rendered in the final HTML.
• {{ block.super }} is added because Django’s admin_change_form_document_ready block contains JavaScript code to handle various operations in the change form and we need that to be rendered too.

Sometimes you’ll need to work with jQuery plugins that are not registered in the django.jQuery namespace. To do that, change how the code listens for events. Instead of wrapping the listener in the django.jQuery namespace, listen to the event triggered from there. For example:

{% extends 'admin/change_form.html' %}
{% load static %}

{% block admin_change_form_document_ready %}
{{ block.super }}
<script src="{% static 'app/unregistered_handlers.js' %}"></script>
{% endblock %}

django.jQuery(document).on('formset:added', function(event, $row, formsetName) {
    // Row added
});

django.jQuery(document).on('formset:removed', function(event, $row, formsetName) {
    // Row removed
});