django-includecontents 0.5.1

Django includecontents component-like tag

Django IncludeContents tag

Provides a component-like {% includecontents %} tag to Django.

For example:

{% load includecontents %}
{% includecontents "hello.html" %}
    <p>World</p>
{% endincludecontents %}

It also provides a simple Django template engine that extends this tag to work like an HTML component.

In this example, it will include and render components/card.html:

<include:card title="Hello">
  <p>World</p>
</include:card>

This engine also allows for multi-line template tags. For example:

{% if 
  user.is_authenticated
  and user.is_staff
%}
...
{% endif %}

Installation

pip install django-includecontents

To use the custom template engine, replace the default DjangoTemplates backend in your settings:

TEMPLATES = [
    {
        'BACKEND': 'includecontents.backend.Templates',
        ...
    },
]

This engine also adds includecontents to the built-in tags so there is no need to load it.

If you don't want the custom engine, just add this app to your INSTALLED_APPS and load the tag in your templates:

INSTALLED_APPS = [
    ...
    'includecontents',
]

{% load includecontents %}

...

{% includecontents %}...{% endincludecontents %}

Template tag usage

The includecontents tag works like the include tag but the contents is rendered and passed to the included template as a contents variable.

{% includecontents "hello.html" %}
    <p>World</p>
{% endincludecontents %}

Named contents blocks

You can also have named contents blocks within the component content.

For example:

{% includecontents "hello.html" %}
    <p>World</p>
    {% contents footer %}Footer{% endcontents %}
{% endincludecontents %}

Where hello.html template could look something like:

<div class="card">
  <div class="content">
    {{ contents }}
  </div>
  {% if contents.footer %}
  <div class="footer">
    {{ contents.footer }}
  </div>
  {% endif %}
</div>

HTML Components Usage

Create a components directory in your templates directory. This is where you will put your component templates that are used via the HTML component format. These components are normal Django templates that will be rendered with an isolated context. The context is passed to the component via component's attributes.

Components must be CamelCase and not match any standard HTML tags.

For example, a components/card.html template could look like:

<div class="card">
  <h2>{{ title }}</h2>
  <div class="content">
    {{ contents }}
  </div>
</div>

Which will allow you to use it like this (without the need to load any template library):

<include:card title="Hello">
  <p>World</p>
</include:card>

You can use named {% contents %} blocks, just like with the includecontents tag.

Some HTML formatters (like prettier) insist on quoting HTML attribute values, you can avoid this by optionally wrapping template values in {}:

<include:card title={mytitle}></include:card>

Component Props

You can define the required or default props of the component in a comment at the top of its template that begins with props (or def to match what JinjaX uses). An exception will be raised if a required prop is not provided.

Any other attributes passed to the component that are not listed in this definition will be added to an attrs context variable that can render them as HTML attributes.

{# props #}
<div {{ attrs }}>
  {{ contents }}
</div>

You can also provide default values for these attributes via the {% attrs %} template tag.

{# props title, large=False #}

<div {% attrs class="card" %}>
...

This example component above would require a title attribute and allow an optional large attribute. Any other attributes will be rendered on the div, with a default class of card if you don't specify a class attribute.

If you want to provide multiple groups of undefined attributes, you can use group.name as the format. Then render them with {{ attrs.group }} (or {% attrs.group %} if you want fallback values).

For example to call a component like this:

<include:field label="Name" name="first_name" value="John" input.class="wide"></include:field>

It could be defined like this:

{# props value, label="" #}

<div {% attrs class="field" %}>
  {% if label %}{{ '<label>'|safe }}{% endif %}
  {{ label }}
  <input {% attrs.input type="text" value=value %}>
  {% if label %}{{ '</label>'|safe }}{% endif %}
</div>

Conditional classes

You can also provide conditional classes for the class attribute using the following format:

{# props large=False #}

{% attrs class="lg" %}     {# sets class attribute to "lg" but can be overridden #}
{% attrs class:lg %}       {# always adds 'lg' class #}
{% attrs class:lg=large %} {# adds 'lg' class if large prop is truthy #}

You can use this same conditional format on the template tag / component itself too:

<include:card title="Hello" class:lg={is_large}>
  <p>World</p>
</include:card>

{% includecontents "hello.html" class:lg=is_large %}
  <p>World</p>
{% endincludecontents %}