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 events
allow this. event.detail.formsetName is the formset the row belongs to.
For the formset:added event, event.target is the newly added row.
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 %}
app/static/app/formset_handlers.js¶document.addEventListener('formset:added', (event) => {
if (event.detail.formsetName == 'author_set') {
// Do something
}
});
document.addEventListener('formset:removed', (event) => {
// Row removed
});
Two points to keep in mind:
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.If your event listener still has to support older versions of Django you have to use jQuery to register your event listener. jQuery handles JavaScript events but the reverse isn’t true.
You could check for the presence of event.detail.formsetName and fall back
to the old listener signature as follows:
function handleFormsetAdded(row, formsetName) {
// Do something
}
$(document).on('formset:added', (event, $row, formsetName) => {
if (event.detail && event.detail.formsetName) {
// Django >= 4.1
handleFormsetAdded(event.target, event.detail.formsetName)
} else {
// Django < 4.1, use $row and formsetName
handleFormsetAdded($row.get(0), formsetName)
}
})
sie 06, 2024