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Extension Configuration


Extensions are able to access, store, and modify settings that define their behavior.

When an extension is enabled, Review Board will load any stored settings from the database, making them available through the settings attribute on the Extension.

Extensions can modify the settings by changing the contents of the dictionary and calling save(). For example:

self.settings['mybool'] = True
self.settings['myint'] = 42
self.settings['mystring'] = 'New Setting Value'

Default Settings

Any settings not explicitly saved by the extension or loaded from the database will be looked up in default_settings. This can be defined on the Extension class.

Here is an example extension setting default_settings:

class SampleExtension(Extension):
    default_settings = {
        'mybool': True,
        'myint': 4,
        'mystring': "I'm a string setting",

If neither settings nor py:attr:default_settings contains the key, a KeyError exception will be thrown.

Configuration Pages

Extensions can provide a configuration page, allowing Review Board administrators to customize the behavior of the extension.

By setting is_configurable to True and providing a admin_urls.py file, a Configure link will be shown in the extension list for the extension. This is only shown when the extension is enabled.

The extension will then need to create a page to present to the user for any customizable settings. Review Board provides some helpers for this, which will be described below.

Configuration URLs

When an extension is configurable, Review Board will load the extension’s admin_urls.py, making those URLs available. An extension can provide whatever it wants in here, but it’s expected to provide at least the root URL, designated by url(r'^$', ...). This should point to the main configuration page.

This file follows the Django URLs format. It must provide a urlpatterns variable, which will contain all the URL patterns. For example:

from django.conf.urls.defaults import patterns, url

urlpatterns = patterns('sample_extension.views',
    url(r'^$', 'configure')

This will call the configure function in sample_extension.views when clicking the Configure link.

Settings Form

Review Board makes it easy to create a basic configuration form for an extension. It provides views, templates, and a form class that does the hard work of loading settings, presenting them to the user, and saving them.

To make use of the provided configuration forms, you’ll want to:

  1. Define a new form class that inherits from djblets.extensions.forms.SettingsForm
  2. Create a new url() entry in admin_urls.py that makes use of the provided configuration view, passing your extension and form classes.

Here is an example form class:

from django import forms
from djblets.extensions.forms import SettingsForm

class SampleExtensionSettingsForm(SettingsForm):
    field1 = forms.IntegerField(min_value=0, initial=1,
                                help_text="Field 1")

And here is an example URL pattern for the form:

from django.conf.urls.defaults import patterns, url

from sample_extension.extension import SampleExtension
from sample_extension.forms import SampleExtensionSettingsForm

urlpatterns = patterns('',
            'ext_class': SampleExtension,
            'form_class': SampleExtensionSettingsForm,

Admin Site (Database Browser)

By setting has_admin_site to True, an extension will be given its own Django database administration site. A button labeled Database will appear in the list of installed extensions, linking to that site.

The extension will also have a admin_site attribute that points to the django.contrib.admin.sites.AdminSite used. This is provided automatically, and is used primarily for the registration of models.

Only models that are registered will appear in the database browser. You can see the documentation on the Django admin site for details on how this works. For example:

from reviewboard.extensions.base import get_extension_manager

from sample_extension.extension import SampleExtension
from sample_extension.models import SampleModel

# You must get the loaded instance of the extension to register to the
# admin site.
extension_manager = get_extension_manager()
extension = extension_manager.get_enabled_extension(SampleExtension.id)

# Register the Model so it will show up in the admin site.