# URL Hooks

```eval_rst
.. note::
    URLs added through URL Hooks are protected by a decorator which ensures the requesting user is logged in and has a main character set.
```

The URL hooks allow you to dynamically specify URL patterns from your plugin app or service. To achieve this you should subclass or instantiate the `services.hooks.UrlHook` class and then register the URL patterns with the hook.

To register a UrlHook class you would do the following:

    @hooks.register('url_hook')
    def register_urls():
        return UrlHook(app_name.urls, 'app_name', r^'app_name/')


The `UrlHook` class specifies some parameters/instance variables required for URL pattern inclusion.

`UrlHook(urls, app_name, base_url)`

#### urls
The urls module to include. See [the Django docs](https://docs.djangoproject.com/en/dev/topics/http/urls/#example) for designing urlpatterns.
#### namespace
The URL namespace to apply. This is usually just the app name.
#### base_url
The URL prefix to match against in regex form. Example `r'^app_name/'`. This prefix will be applied in front of all URL patterns included. It is possible to use the same prefix as existing apps (or no prefix at all) but [standard URL resolution](https://docs.djangoproject.com/en/dev/topics/http/urls/#how-django-processes-a-request) ordering applies (hook URLs are the last ones registered).

### Example

An app called `plugin` provides a single view:

    def index(request):
        return render(request, 'plugin/index.html')

The app's `urls.py` would look like so:

    from django.urls import path
    import plugin.views

    urlpatterns = [
        path('index/', plugins.views.index, name='index'),
    ]

Subsequently it would implement the UrlHook in a dedicated `auth_hooks.py` file like so:

    from alliance_auth import hooks
    from services.hooks import UrlHook
    import plugin.urls

    @hooks.register('url_hook')
    def register_urls():
        return UrlHook(plugin.urls, 'plugin', r^'plugin/')

When this app is included in the project's `settings.INSTALLED_APPS` users would access the index view by navigating to `https://example.com/plugin/index`.
