django-widgets

An alternative for templatetags. Based on http://code.google.com/p/django-widgets/

Background

Django template tags are great, but writing renderes and compiler functions is often boring (ie. parsing options).

Common usage of widgets is similar to {% with %}..{% include %} pair, but provides easy-to-use interface for more complex view-logic code.

Major features are:

• class-based style
• widgets registry with autodiscovering.

Django-widgets provides two useful templatetags with option parsers:

• include_widget

  Simply includes widget instance found in registry by name, calls widget`s render() method with provided optional value and configuration.

  Syntax:

  {% include_widget widget_name [value] [option1=value1, [option2=value2, ...]] %}

  • value: optional value passed as value in get_context() and render() methods
  • opt1=val1: dictionary key-value pairs passed as options in get_context() and render()

• widget

  Same as include_widget tag, but template source is taken from tag content instead of widget`s default template.

  Everything within {% widget %} and {% endwidget %} is used as template source. Also this template tag does NOT call widget`s render() method, but get_context() instead.

Hints:

• Context of your view will be unchanged.
• Context of widget contains all view variables, similar to {% with %} tag. No more hacks like {{ settings.MEDIA_URL }} nor {% get_media_url %} :)

Defining a Widget

Widgets should extend from django_widgets.base.Widget class. Every widget, placed in widgets.py module of your app, is automatically registered by name (from class.__name__)

Simplest "hello world" widget example (place it in yourapp/widgets.py module):

from django_widgets import Widget

class HelloWorld(Widget):
    def render(self, context, value=None, options=None):
        return u'Hello world!'

Calling from template:

{% load widgets %}

<h1>{% include_widget HelloWorld %}</h1>

Base Widget class has render() method which uses class-property template for rendering. But if not set render() raises NotImplementedError.

Example of widget with custom template:

from django_widgets import Widget
from catalog import Category

class CategoryTree(Widget):
    template = 'catalog/category_tree_widget.html'

    def get_context(self, root_category, options, context=None):
        return {
            'tree': Category.objects.get_tree_for(root_category),
            'root_category': root_category,
            'max_level': options.get('max_level', 3),
            }

In template:

{% load widgets %}

{% include_widget CategoryTree max_level=1 %}

The catalog/category_tree_widget.html template will be used for rendering tree of categories.

Or use inline tempalte with {% widget %} tag:

{% load widgets %}

{% widget CategoryTree max_level=1 %}
    <div>
        ... widget template ...
    </div>
{% endwidget %}