# Django 3.0.9.dev - dokumentacja

# 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 type="text/javascript" src="{% static 'app/formset_handlers.js' %}"></script>
    {% endblock %}

app/static/app/formset_handlers.js

    (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 type="text/javascript" src="{% static 'app/unregistered_handlers.js' %}"></script>
    {% endblock %}

app/static/app/unregistered_handlers.js

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

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