plain.elements
Use HTML tags to include HTML template components.
Overview
Elements are an alternative to Jinja {% include %} or macros and flow better with existing HTML by using a compatible syntax. They are distinguished from built-in HTML tags by using a capitalized tag name (so <Button> doesn't clash with <button>).
To make a <Submit> element, for example, you would create a template named templates/elements/Submit.html.
<!-- templates/elements/Submit.html -->
<button type="submit" class="btn">
{{ children }}
</button>
An element can be used in any other template by enabling them with {% use_elements %} and then using the capitalized tag name.
{% extends "admin/base.html" %}
{% use_elements %}
{% block content %}
<form method="post">
{{ csrf_input }}
<!-- Form fields here -->
<Submit>Save</Submit>
</form>
{% endblock %}
Element attributes
Attributes will be passed through using regular strings or single braces {} for Python variables.
{% extends "admin/base.html" %}
{% use_elements %}
{% block content %}
<form method="post">
{{ csrf_input }}
<FormInput field={form.username} placeholder="Username" label="Username" />
<Submit>Save</Submit>
</form>
{% endblock %}
The attributes are passed to the element as named variables. By default in Plain, you will get an error if you try to use an undefined variable, so Jinja features like |default and is defined are useful for optional attributes.
<!-- templates/elements/FormInput.html -->
<label for="{{ field.html_id }}">
{{ label }}
</label>
<input
id="{{ field.html_id }}"
type="{{ type|default('text') }}"
name="{{ field.html_name }}"
value="{{ field.value() or '' }}"
placeholder="{{ placeholder }}"
{% if field.field.required %}required{% endif %}
/>
Namespaced elements
Especially for reusable packages, it can be useful to namespace your elements by putting them in a subdirectory of templates/elements/. To use namespaced elements, you need to include the full dot-separated path in your HTML tag.
For example, an element in templates/elements/admin/Submit.html would be used like this:
{% use_elements %}
{% block content %}
<form method="post">
{{ csrf_input }}
<admin.Submit>Save</admin.Submit>
</form>
{% endblock %}
Installation
Install the plain.elements package from PyPI:
uv add plain.elements
Add it to your INSTALLED_PACKAGES setting. That's it! The Jinja extension will be enabled automatically.
# settings.py
INSTALLED_PACKAGES = [
# ...
"plain.elements",
]