Extending client-side behaviour¶
Many kinds of common customisations can be done without reaching into JavaScript, but depending on what parts of the client-side interaction you want to leverage or customise, you may need to employ React, Stimulus, or plain (vanilla) JS.
React is used for more complex parts of Wagtail, such as the sidebar, commenting system, and the Draftail rich-text editor. For basic JavaScript-driven interaction, Wagtail is migrating towards Stimulus.
You don’t need to know or use these libraries to add your custom behaviour to elements, and in many cases, simple JavaScript will work fine, but Stimulus is the recommended approach for more complex use cases.
You don’t need to have Node.js tooling running for your custom Wagtail installation for many customisations built on these libraries, but in some cases, such as building packages, it may make more complex development easier.
Note
Avoid using jQuery and undocumented jQuery plugins, as they will be removed in a future version of Wagtail.
Adding custom JavaScript¶
Within Wagtail’s admin interface, there are a few ways to add JavaScript.
The simplest way is to add global JavaScript files via hooks, see insert_editor_js and insert_global_admin_js.
For JavaScript added when a specific Widget is used you can add an inner Media
class to ensure that the file is loaded when the widget is used, see Django’s docs on their form Media
class.
In a similar way, Wagtail’s Template components provide a media
property or Media
class to add scripts when rendered.
These will ensure the added files are used in the admin after the core JavaScript admin files are already loaded.
Extending with DOM events¶
When approaching client-side customisations or adopting new components, try to keep the implementation simple first, you may not need any knowledge of Stimulus, React, JavaScript Modules or a build system to achieve your goals.
The simplest way to attach behaviour to the browser is via DOM Events and plain (vanilla) JavaScript.
Wagtail’s custom DOM events¶
Wagtail supports some custom behaviour via listening or dispatching custom DOM events.
Extending with Stimulus¶
Wagtail uses Stimulus as a way to provide lightweight client-side interactivity or custom JavaScript widgets within the admin interface.
The key benefit of using Stimulus is that your code can avoid the need for manual initialisation when widgets appear dynamically, such as within modals, InlinePanel
, or StreamField
panels.
The Stimulus handbook is the best source on how to work with and understand Stimulus.
Adding a custom Stimulus controller¶
Wagtail exposes two client-side globals for using Stimulus.
window.wagtail.app
the core admin Stimulus application instance.window.StimulusModule
Stimulus module as exported from@hotwired/stimulus
.
First, create a custom Stimulus controller that extends the base window.StimulusModule.Controller
using JavaScript class inheritance. If you are using a build tool you can import your base controller via import { Controller } from '@hotwired/stimulus';
.
Once you have created your custom controller, you will need to register your Stimulus controllers manually via the window.wagtail.app.register
method.
A simple controller example¶
First, create your HTML so that appears somewhere within the Wagtail admin.
<!-- Will log 'My controller has connected: hi' to the console -->
<div data-controller="my-controller">Hi</div>
<!-- Will log 'My controller has connected: hello' to the console, with the span element-->
<div data-controller="my-controller">
Hello <span data-my-controller-target="label"></span>
</div>
Second, create a JavaScript file that will contain your controller code. This controller logs a simple message on connect
, which is once the controller has been created and connected to an HTML element with the matching data-controller
attribute.
// myapp/static/js/example.js
class MyController extends window.StimulusModule.Controller {
static targets = ['label'];
connect() {
console.log(
'My controller has connected:',
this.element.innerText,
this.labelTargets,
);
}
}
window.wagtail.app.register('my-controller', MyController);
Finally, load the JavaScript file into Wagtail’s admin with a hook.
# myapp/wagtail_hooks.py
from django.templatetags.static import static
from django.utils.safestring import mark_safe
from wagtail import hooks
@hooks.register('insert_global_admin_js')
def global_admin_js():
return mark_safe(
f'<script src="{static("js/example.js")}"></script>',
)
You should now be able to refresh your admin that was showing the HTML and see two logs in the console.
A more complex controller example¶
Now we will create a WordCountController
that adds a small output
element next to the controlled input
element that shows a count of how many words have been entered.
// myapp/static/js/word-count-controller.js
class WordCountController extends window.StimulusModule.Controller {
static values = { max: { default: 10, type: Number } };
connect() {
this.setupOutput();
this.updateCount();
}
setupOutput() {
if (this.output) return;
const template = document.createElement('template');
template.innerHTML = `<output name='word-count' for='${this.element.id}' class='output-label'></output>`;
const output = template.content.firstChild;
this.element.insertAdjacentElement('beforebegin', output);
this.output = output;
}
updateCount(event) {
const value = event ? event.target.value : this.element.value;
const words = (value || '').split(' ');
this.output.textContent = `${words.length} / ${this.maxValue} words`;
}
disconnect() {
this.output && this.output.remove();
}
}
window.wagtail.app.register('word-count', WordCountController);
This lets the data attribute data-word-count-max-value
determine the ‘configuration’ of this controller and the data attribute actions to determine the ‘triggers’ for the updates to the output element.
# models.py
from django import forms
from wagtail.admin.panels import FieldPanel
from wagtail.models import Page
class BlogPage(Page):
# ...
content_panels = Page.content_panels + [
FieldPanel('subtitle', classname="full"),
FieldPanel(
'introduction',
classname="full",
widget=forms.TextInput(
attrs={
'data-controller': 'word-count',
# allow the max number to be determined with attributes
# note we can use Python values here, Django will handle the string conversion (including escaping if applicable)
'data-word-count-max-value': 5,
# decide when you want the count to update with data-action
# (e.g. 'blur->word-count#updateCount' will only update when field loses focus)
'data-action': 'word-count#updateCount paste->word-count#updateCount',
}
)
),
#...
This next code snippet shows a more advanced version of the insert_editor_js
hook usage which is set up to append additional scripts for future controllers.
# wagtail_hooks.py
from django.utils.html import format_html_join
from django.templatetags.static import static
from wagtail import hooks
@hooks.register('insert_editor_js')
def editor_js():
# add more controller code as needed
js_files = ['js/word-count-controller.js',]
return format_html_join('\n', '<script src="{0}"></script>',
((static(filename),) for filename in js_files)
)
You should be able to see that on your Blog Pages, the introduction field will now have a small output
element showing the count and max words being used.
A more complex widget example¶
For more complex widgets we can now integrate additional libraries whenever the widget appears in the rendered HTML, either on initial load or dynamically without the need for any inline script
elements.
In this example we will build a color picker widget using the Coloris JavaScript library with support for custom widget options.
First, let’s start with the HTML, building on the Django widgets system that Wagtail supports for FieldPanel
and FieldBlock
. Using the build_attrs
method, we build up the appropriate Stimulus data attributes to support common data structures being passed into the controller.
Observe that we are using json.dumps
for complex values (a list of strings in this case), Django will automatically escape these values when rendered to avoid common causes of insecure client-side code.
# myapp/widgets.py
import json
from django.forms import Media, TextInput
from django.utils.translation import gettext as _
class ColorWidget(TextInput):
"""
See https://coloris.js.org/
"""
def __init__(self, attrs=None, swatches=[], theme='large'):
self.swatches = swatches
self.theme = theme
super().__init__(attrs=attrs);
def build_attrs(self, *args, **kwargs):
attrs = super().build_attrs(*args, **kwargs)
attrs['data-controller'] = 'color'
attrs['data-color-theme-value'] = self.theme
attrs['data-color-swatches-value'] = json.dumps(swatches)
return attrs
@property
def media(self):
return Media(
js=[
# load the UI library
"https://cdn.jsdelivr.net/gh/mdbassit/Coloris@latest/dist/coloris.min.js",
# load controller JS
"js/color-controller.js",
],
css={"all": ["https://cdn.jsdelivr.net/gh/mdbassit/Coloris@latest/dist/coloris.min.css"]},
)
For the Stimulus controller, we pass the values through to the JavaScript library, including a reference to the controlled element via this.element.id
.
// myapp/static/js/color-controller.js
class ColorController extends window.StimulusModule.Controller {
static values = { swatches: Array, theme: String };
connect() {
// create
Coloris({ el: `#${this.element.id}` });
// set options after initial creation
setTimeout(() => {
Coloris({ swatches: this.swatchesValue, theme: this.themeValue });
});
}
}
window.wagtail.app.register('color', ColorController);
Now we can use this widget in any FieldPanel
or any FieldBlock
for StreamFields, it will automatically instantiate the JavaScript to the field’s element.
# blocks.py
# ... other imports
from django import forms
from wagtail.blocks import FieldBlock
from .widgets import ColorWidget
class ColorBlock(FieldBlock):
def __init__(self, *args, **kwargs):
swatches = kwargs.pop('swatches', [])
theme = kwargs.pop('theme', 'large')
self.field = forms.CharField(widget=ColorWidget(swatches=swatches, theme=theme))
super().__init__(*args, **kwargs)
# models.py
# ... other imports
from django import forms
from wagtail.admin.panels import FieldPanel
from .blocks import ColorBlock
from .widgets import ColorWidget
BREAD_COLOR_PALETTE = ["#CFAC89", "#C68C5F", "#C47647", "#98644F", "#42332E"]
class BreadPage(Page):
body = StreamField([
# ...
('color', ColorBlock(swatches=BREAD_COLOR_PALETTE)),
# ...
], use_json_field=True)
color = models.CharField(blank=True, max_length=50)
# ... other fields
content_panels = Page.content_panels + [
# ... other panels
FieldPanel("body"),
FieldPanel("color", widget=ColorWidget(swatches=BREAD_COLOR_PALETTE)),
]
Using a build system¶
You will need ensure your build output is ES6/ES2015 or higher. You can use the exposed global module at window.StimulusModule
or provide your own using the npm module @hotwired/stimulus
.
// myapp/static/js/word-count-controller.js
import { Controller } from '@hotwired/stimulus';
class WordCountController extends Controller {
// ... the same as above
}
window.wagtail.app.register('word-count', WordCountController);
You may want to avoid bundling Stimulus with your JavaScript output and treat the global as an external/alias module, refer to your build system documentation for instructions on how to do this.
Extending with React¶
To customise or extend the React components, you may need to use React too, as well as other related libraries.
To make this easier, Wagtail exposes its React-related dependencies as global variables within the admin. Here are the available packages:
// 'focus-trap-react'
window.FocusTrapReact;
// 'react'
window.React;
// 'react-dom'
window.ReactDOM;
// 'react-transition-group/CSSTransitionGroup'
window.CSSTransitionGroup;
Wagtail also exposes some of its own React components. You can reuse:
window.wagtail.components.Icon;
window.wagtail.components.Portal;
Pages containing rich text editors also have access to:
// 'draft-js'
window.DraftJS;
// 'draftail'
window.Draftail;
// Wagtail’s Draftail-related APIs and components.
window.draftail;
window.draftail.DraftUtils;
window.draftail.ModalWorkflowSource;
window.draftail.ImageModalWorkflowSource;
window.draftail.EmbedModalWorkflowSource;
window.draftail.LinkModalWorkflowSource;
window.draftail.DocumentModalWorkflowSource;
window.draftail.Tooltip;
window.draftail.TooltipEntity;