This Django app aims to make dynamic formsets convenient for users and developers alike. It extends Django's built-in formset classes and includes support for adding, deleting and ordering of forms in the browser. JavaScript events are dispatched when forms are added, deleted or reordered, for executing custom logic.
- Django: 4.2+
- Python: 3.8+
- Tested desktop browsers: latest Chrome, latest Firefox, latest Edge, latest Opera, latest Safari
Other platform versions may work, but are not actively tested.
-
Install using pip:
$ pip install django-convenient-formsets
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Add to
INSTALLED_APPS:INSTALLED_APPS = [ # ... 'convenient_formsets' ]
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Create a formset in your Python code:
from convenient_formsets import ConvenientBaseFormSet from django import forms class EmailForm(forms.Form): email = forms.EmailField() EmailFormSet = forms.formset_factory( EmailForm, formset=ConvenientBaseFormSet, can_delete=True, can_order=True, ) email_formset = EmailFormSet(prefix='email-formset')
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Render formset in your template and add JavaScript code for initialization:
<!doctype html> <html> <head> <!-- Include the formset's media --> {{ email_formset.media }} <!-- Initialize a ConvenientFormset --> <script> window.addEventListener('load', function(event) { new ConvenientFormset({ 'formsetPrefix': '{{ email_formset.prefix }}', 'formsContainerSelector': '#email-formset #email-forms-container', 'formSelector': '.email-form', 'canAddForms': true, 'addFormButtonSelector': '#email-formset #add-form-button', 'emptyFormTemplateSelector': '#email-formset #empty-form-template', 'canDeleteForms': true, 'deleteFormButtonSelector': '.delete-form-button', 'canOrderForms': true, 'moveFormDownButtonSelector': '.move-form-down-button', 'moveFormUpButtonSelector': '.move-form-up-button', }); }); </script> </head> <body> <!-- Render formset using the following basic structure --> <div id="email-formset"> <div id="email-forms-container"> {% for email_form in email_formset.forms %} <div class="email-form"> {{ email_form.email }} {% if email_formset.can_delete %} {{ email_form.DELETE }} <input type="button" class="delete-form-button" value="Delete"> {% endif %} {% if email_formset.can_order %} {{ email_form.ORDER }} <input type="button" class="move-form-up-button" value="Move up"> <input type="button" class="move-form-down-button" value="Move down"> {% endif %} </div> {% endfor %} </div> <div><input type="button" id="add-form-button" value="Add another"></div> <template id="empty-form-template"> <div class="email-form"> {{ email_formset.empty_form.email }} {% if email_formset.can_delete %} <input type="button" class="delete-form-button" value="Delete"> {% endif %} {% if email_formset.can_order %} {{ email_form.ORDER }} <input type="button" class="move-form-up-button" value="Move up"> <input type="button" class="move-form-down-button" value="Move down"> {% endif %} </div> </template> {{ email_formset.management_form }} </div> </body> </html>
The Python classes ConvenientBaseFormSet, ConvenientBaseModelFormSet and
ConvenientBaseInlineFormSet extend Django's built-in BaseFormSet,
BaseModelFormSet and BaseInlineFormSet by:
- Overriding
deletion_widgetfor theDELETEfield andordering_widgetfor theORDERfield. They default to theforms.HiddenInputwidget in order to hide them from the user. - Including the JavaScript file in the formset's
mediaattribute required for dynamic formsets.
See the example in the Quick start guide above on how to render the formset in your HTML template. Feel free to add some intermediate DOM elements if it suits your template better, as long as you stick to the basic structure shown above.
It is important that both the visible forms and the empty form follow the same structure. A form also needs to be contained inside a single parent element, denoted by the formSelector parameter:
<!-- Visible forms inside forms container -->
<div id="email-forms-container">
<div class="email-form">
<!-- Form -->
</div>
</div>
<!-- Empty form inside template element -->
<template id="empty-form-template">
<div class="email-form">
<!-- Form -->
</div>
</template>Creating an instance of the JavaScript constructor function ConvenientFormset
allows a user to add, delete and reorder forms within the rendered formset.
When a user makes changes, the management form is updated accordingly. The
constructor function can be passed the parameters outlined below. In case
initialization fails, check the browser console for some helpful output.
- formsetPrefix
- The formset's "prefix" attribute (required).
- formsContainerSelector
- CSS selector for the DOM element that contains all the forms (required).
- formSelector
- CSS selector for each form within "formsContainerSelector" (required).
- canAddForms
- Enables adding of new forms (default: true).
- addFormButtonSelector
- CSS selector for the DOM element that may be clicked to add an empty form (required if "canAddForms" is set).
- emptyFormTemplateSelector
- CSS selector for the empty form <template> element (required if "canAddForms" is set).
- hideAddFormButtonOnMaxForms
- Hides the add button when reaching the maximum number of forms, by applying the "hidden" HTML attribute (default: true).
- canDeleteForms
- Enables deleting of forms (default: false).
- deleteFormButtonSelector
- CSS selector for the DOM element within "formSelector" that may be clicked to delete a form (required if "canDeleteForms" is set).
- canOrderForms
- Enables ordering of forms (default: false).
- moveFormDownButtonSelector
- CSS selector for the DOM element within "formSelector" that may be clicked to move a form down among the visible forms (required if "canOrderForms" is set).
- moveFormUpButtonSelector
- CSS selector for the DOM element within "formSelector" that may be clicked to move a form up among the visible forms (required if "canOrderForms" is set).
When adding, deleting or reordering forms, custom JavaScript events are dispatched to allow for executing custom JavaScript code:
- convenient_formset:added
- Dispatched when a form is added to the formset.
- convenient_formset:removed
- Dispatched when a form is removed to the formset.
- convenient_formset:movedDown
- Dispatched when a form is moved downwards while reordering forms inside the formset.
- convenient_formset:movedUp
- Dispatched when a form is moved upwards while reordering forms inside the formset.
All events will contain the formsetPrefix parameter value in the event's
detail property.
These events can be handled in the following way:
document.addEventListener('convenient_formset:added', (event) => {
if (event.detail.formsetPrefix === 'email-formset') {
// Handle event for a specific formset on the webpage
}
});
document.addEventListener('convenient_formset:removed', (event) => {
// Handle event for any formset on the webpage
});Form deletion is handled in either of the following ways:
- If a form includes a
DELETEfield, the field's value is updated and the form will be hidden by applying the "hidden" HTML attribute. The deletion will then be handled server side. - If the form does not include a
DELETEfield, the form is removed from the DOM altogether and will not be submitted to the server.
Form ordering is handled by moving visible forms above the previous (up)
and below the next (down) for visual feedback, and by swapping the values of
their ORDER fields for the server side. This means that the original values
are kept, even when in-between forms are deleted. New forms will see the
initial value for their ORDER field set to the last visible form's ORDER
field value + 1, as they're added to the bottom of all forms.
The scripts and documentation in this project are released under the BSD-3-Clause License.