django-navutils 0.6

A lightweight package for handling menus and breadcrumbs in your django project

Note: this package is still in beta. It has been successfully used in a few projects of my own. However, API may be subject to backward incompatible changes until the first major version is released.

Django-navutils is a lightweight package for handling menu and breadcrumbs inside your django project.

• Features
• Requirements
• Install
• Usage
  • Menus
  • Breadcrumbs
• Changelog
• License

Features

• No database involved (unless you want it): menus and breadcrumbs are plain old python code
• Highly customizable
• Conditionnal menu items display: you want to show a menu link to authenticated users only ? Anonymous ? Staff members ? A custom criteria ? You’re covered !
• i18n-friendly: you can rely on usual django translation mechanisms
• Unlimited menus
• Semi-automatic current menu node detection

Requirements

• Python >= 2.7 or >= 3.3
• Django >= 1.7

The menu system may be integrated in any project, but the breadcrumbs part requires that you use class-based views.

Install

Package is available on pip and can be installed via pip install django-navutils.

You’ll also have to add navutils to your settings.INSTALLED_APPS

Also add the following to settings.CONTEXT_PROCESSORS:

CONTEXT_PROCESSORS = (
    # ...
    'navutils.context_processors.menus',
)

Usage

Menus

Navutils represents menus using Menu and Node instances, each menu being a collection of node instances representing a menu link. Nodes may have children, which are also Node instances.

Let’s see a minimal example.

yourapp/menu.py:

from navutils import menu

main_menu = menu.Menu('main')
menu.register(main_menu)

# will be shown to everybody
blog = menu.Node(id='blog', label='Blog', pattern_name='blog:index')
main_menu.register(blog)

# nodes created with a pattern_name argument will use django reverse
assert blog.get_url() == '/blog'

# if you want to disable reversion, use the url argument
django = menu.Node(id='django',
                   label='Django project',
                   url='http://djangoproject.com',
                   link_attrs={'target': '_blank'})

# Each node instance can accept an arbitrary number of children
blog.add(
    menu.Node(id='last_entries',
              label='Last entries',
              pattern_name='blog:last_entries')
)
blog.add(
    menu.Node(id='archives', label='Archives', pattern_name='blog:archives')
)

# will be shown to anonymous users only
login = menu.AnonymousNode(id='login',
                           label='Login',
                           pattern_name='accounts_login',
                           link_attrs={'class': 'big-button'})
main_menu.register(login)

# will be shown to authenticated users only
logout = menu.AuthenticatedNode(id='logout',
                                label='Logout',
                                pattern_name='accounts_logout')
main_menu.register(logout)

yourapp/templates/index.html:

{% load navutils_tags %}
{% render_menu menu=menus.main user=request.user %}

For an anonymous user, this would output something like:

<nav class="main-menu">
    <ul>
        <li class="has-children menu-item">
            <a href="/blog">Blog<a>
            <ul class="sub-menu">
                <li class="menu-item">
                    <a href="/blog/latest">Latest entries</a>
                </li>
                <li class="menu-item">
                    <a href="/blog/archives">Archives</a>
                </li>
            </ul>
        </li>
        <li class="menu-item">
            <a href="http://djangoproject.com" target="_blank">Django project</a>
        </li>
        <li class="menu-item">
            <a href="/login" class="big-button">Login</a>
        </li>
    </ul>
</nav>

You can also directly set children nodes on parent instanciation with the children argument:

user = menu.Node(
    id='user',
    label='Greetings',
    pattern_name='user:dashboard',
    children=[
        menu.Node(id='logout', label='Logout', pattern_name='user:logout'),

        # you can nest children indefinitely
        menu.Node(
            id='settings',
            label='Settings',
            pattern_name='user:settings',
            children = [
                menu.Node(id='newsletter',
                          label='Newsletter',
                          pattern_name='user:settings:newsletter')
            ],
        ),
    ]
)

Nodes can be customized in many ways:

heavily_customized_node = menu.Node(
    'customized',
    'My custom menu',
    url='#',

    # a custom CSS class that will be applied to the node on rendering
    css_class='custom-class',

    # the <a> title attribute
    title='click me!',

    # a path to a custom template for rendering the node
    template='myapp/menu/mynode.html',

    # extra context you can use in your node template
    context={'foo': 'bar'},

    # a dict of attributes that will be applied as HTML attributes on the <li>
    attrs = {'style': 'background-color: white;'}

    # a dict of attributes that will be applied as HTML attributes on the <a>
    link_attrs = {'target': '_blank', 'data-something': 'fancy-stuff'}
)

Current node

You’ll probably want to highlight the current node in some way. Navutils provide a view mixin you an inherit from in order to achieve this.

Assuming the following menu:

from navutils import menu

main_menu = menu.Menu(id='main')
menu.register(main_menu)

login = menu.Node(id='login', label='Login', pattern_name='account_login')
main_menu.register(login)

You can bind a view to a menu node with the following code:

from navutils import MenuMixin

class Login(MenuMixin, TemplateView):
    current_menu_item = 'login'

Under the hood, the mixin will pass the value to the context and a current class will be added

to the login node if the view is displayed. Note that you can achieve the same result with django function-based views, as long as you manually pass the node identifier in the context, under the current_menu_item key.

Node reference

Navutils provide a few node subclasses that address common use cases.

Node

The base Node type, will be displayed to anybody.

AnonymousNode

Displayed to anonymous users only.

AuthenticatedNode

Displayd to authenticated users only.

StaffNode

Displayed to staff users/superusers only.

PermissionNode

Displayed to users that have the given permission. Usage:

vip_node = menu.PermissionNode('vip',
                               label='VIP Area',
                               pattern_name='vip:index',
                               permission='access_vip_area')

AllPermissionsNode

Displayed to users that match a list of permission. Usage:

permissions = ['myapp.access_vip_area', 'myapp.drink_champagne']
champagne_node = menu.AllPermissionsNode('champagne',
                                         label='Champagne!',
                                         pattern_name='vip:champagne',
                                         permissions=permissions)

AnyPermissionsNode

Displayed to users that match any given permission. Usage:

permissions = ['myapp.can_party', 'myapp.can_have_fun']
have_a_good_time = menu.AnyPermissionsNode('good-time',
                                           label='Have a good time',
                                           pattern_name='good_time',
                                           permissions=permissions)

PassTestNode

Displayed to users that match a custom test. Usage:

def can_drink_alcohol(user, context):
    return user.age >= 21 or user.looks_mature_for_his_age

drink_alcohol = menu.PassTestNode('drink',
                                  label='Have a beer',
                                  pattern_name='beer',
                                  test=can_drink_alcohol)

If it’s not enough, you can also override the default templates:

• navutils/menu.html : the menu wrapper that loop through the nodes
• navutils/node.html : called for displaying each node instance

And of course, you’re free to create your own sub-classes.

Breadcrumbs

Breadcrumbs are set up into views, and therefore can only be used with class-based views.

First of all, you’ll probably want to define a base mixin for all your views:

from navutils import BreadcrumbsMixin, Breadcrumb

class BaseMixin(BreadcrumbsMixin):
    def get_breadcrumbs(self):
        breadcrumbs = super(BaseMixin, self).get_breadcrumbs()
        breadcrumbs.append(Breadcrumb('Home', url='/'))
        return breadcrumbs

Then, you can inherit from this view everywhere:

# breadcrumbs = Home > Blog
class BlogView(BaseMixin):
    title = 'Blog'


# breadcrumbs = Home > Logout
class LogoutView(BaseMixin):
    title = 'Logout'

By default, the last element of the breadcrumb is deduced from the title attribute of the view. However, for a complex hierarchy, you are free to override the get_breadcrumbs method:

# you can trigger url reversing via pattern_name, as for menu nodes
class BlogMixin(BaseMixin)
    def get_breadcrumbs(self):
        breadcrumbs = super(BlogMixin, self).get_breadcrumbs()
        breadcrumbs.append(Breadcrumb('Blog', pattern_name='blog:index'))
        return breadcrumbs


# breadcrumbs = Home > Blog > Last entries
class BlogIndex(BlogMixin):
    title = 'Last entries'


# for dynamic titles, just override the get_title method
# breadcrumbs = Home > Blog > My category name
class CategoryDetail(BlogMixin, DetailView):

    model = Category

    def get_title(self):
        # assuming your Category model has a title field
        return self.object.title

The last step is to render the breadcrumbs in your template. The provided mixin takes care with passing data in the context, so all you need is:

{% load navutils_tags %}

{% render_breadcrumbs breadcrumbs %}

The breadcrumbs part of navutils is bundled with two templates, feel free to override them:

• navutils/breadcrumbs.html: the breadcrumbs wrapper
• navutils/crumb.html: used to render each crumb

That’s it !

Changelog

See CHANGES.rst.

License

Project is licensed under BSD license.