site-config 1.1.0

Django configuration Utility to manage multiple "websites" in a project.

ABOUT

This module provides you an API that lets you code django applications such that those apps can segment themselves into multiple sections and have different settings for each section.

For example, say I want to use the same app under two different url paths and have different behavior (different settings) for both.

/mysite1/myapp/
/mysite2/myapp/

Also, say I want to enable or disable individual apps on those different urls, via an admin interface.

Also, say I want to have a consistent way to define settings for those apps.

This module helps you to accomplish those things.

INSTALL

Install from pip

pip install site_config

Install from Github

git clone https://github.com/ImaginaryLandscape/django_site_config.git

CONFIGURATION

This application allows you to specify different siteconfig backends. The siteconfig backend is responsible for getting and setting settings from/to a persistent location.

Currently, two backends are present in this module:

• model_backend
• settings_backend

The model_backend stores configuration settings in a set of database models. It allows for customizing the settings for a given app inside of the admin interface and allows for different settings for different 'websites' inside an app. Choosing this backend enables an Django admin module for setting these settings.

The settings_backend is a simple backend that uses settings.py. This is not dynamic; when an application needs a setting, this backend just looks it up from settings.py.

Add to INSTALLED_APPS in settings.py

'site_config',

# If using model_backend
'site_config.backends.model_backend',
 
# if using settings_backend
'site_config.backends.settings_backend',

If the model backend is used, the Website, Application, and WebsiteApplication models defined in models.py should appear in the Django admin. If the settings backend is used, they should not appear.

Site specific base templates may also be used if the following context processor is add to TEMPLATE_CONTEXT_PROCESSORS in settings.py

'site_config.context_processors.decide_base_template'

This sets a new context variable base_template so that the contents of your base.html template can extend a variable. Instead of including all template logic in your projects base.html template, you can move this logic to another template (base_site.html, for instance) and have base.html be:

{% extends base_template|default:"base_site.html" %}

Now in much the same way you can override templates (explained later in this document), you can create a base_site.html template inside your site's template folder that will be used if present.

GLOBAL SETTINGS in settings.py

SITECONFIG_BACKEND_DEFAULT (optional) = This specifies the default backend that is to be used. If this setting is not defined, it defaults to the model_backend.

Valid values for this are as follows:

"site_config.backends.model_backend.DatabaseBackend"  # model_backend
"site_config.backends.settings_backend.SettingsBackend"  # settings_backend

SITECONFIG_BASE_TEMPLATE (optional) = This specifies what the default base template should be when using the decide_base_template context processor. If this context processor is not used, this setting has no effect.

CONFIGURING THE settings_backend

Set the following in settings.py

• SITECONFIG_SITEAPP_STATUS (optional) - This sets whether or not apps using this module should be marked as active or not. Valid values are: "disabled", "curtained", or "enabled" The default is "enabled"

• SITECONFIG_CURTAIN_MESSAGE (optional) = This sets the curtain message string when SITECONFIG_SITEAPP_STATUS is set to "curtained".

CONFIGURING THE model_backend

You need to run the following if using the model_backend:

./manage.py syncdb
./manage.py migrate 

USAGE

In order to use this system, you have to implement several things in your application.

1. Create a configuration class

   Create add the following class in a django app's init.py, models.py or some other location that is called when django first executes. Define "application_short_name" and "application_verbose_name" attributes.

   Implement the "get_default_configs()" method. This must return a configuration dictionary where the keys are the configuration variables for the application, and the values are nested metadata dictionaries.

   Each nested dictionary must contain 3 keys:

   • default = the default value that the key will take
   • field = a django Field instance used to validate the value
   • help (optional) = a help text entry that describes the key
   • choices (optional) = a list of tuples constraining the input. Only works with fields that are like ChoiceField that take choices as part of the constructor i.e. (('a_short_name','A text'),('b_short_name', 'B text'))

   You also need to register the config class with the "register()" method.

   See the example below:

   /path/to/myproject/myapp/init.py

   import site_config
   
   class FooSiteConfig(site_config.SiteConfigBase):
   
       application_short_name = "foo"
       application_verbose_name = "Foo Application"
       
       # Optionally override if you want to customize the backend
       # used for a given config.
       def get_backend(self):
           backend = getattr(settings, 'SITECONFIG_BACKEND_DEFAULT',
               'site_config.backends.model_backend.DatabaseBackend')
           return backend
       
       def get_default_configs(self):
           return {'TEST_A':{'default':"Test A default", 
                             'field':'django.forms.CharField', 
                             'help':'Test A help text.'}, 
                   "TEST_B":{'default':1, 
                             'field':'django.forms.IntegerField', 
                             'help':'Test B help text.'}}
   
   site_config.registy.config_registry.register(MyAppSiteConfig)
   

2. Enable and disable urls via enable_disable_website() decorator

   In order to make use django_site_config's ability to enable and disable particular views, you need to wrap your urls as follows. In order to use this website switching functionality, you need to pass in the "website" kwarg as part of the url string.

   /path/to/myproject/myapp/urls.py

   from django.conf.urls import patterns, include, url
   from site_config.decorators import enable_disable_website, decorated_includes
   from example.app_foo import FooConfig
   from .views import IndexView
   
   # Wrap a single url 
   
   urlpatterns = [
      url('^(?P<website>[\w-]+)/foo/$', 
          enable_disable_website(IndexView.as_view(
              template_name='index.html'), FooConfig), 
          {}, 
          name="app_foo_index"
      )
   ]
   
   # OR you can decorate an entire include
   
   urlpatterns += decorated_includes(lambda func: enable_disable_website(func, BarConfig),
       patterns('', url(r'^(?P<website>[\w-]+)/bar/', include('example.app_bar.urls')))
   )
   

Note: You can also use this enable_disable_website() function to decorate a django CBV or FBV according to the django documentation.

Note: Your views must accept the 'website' keyword argument.

3. Allow template overrides

   This module also provides a means to override templates for a specific site.

   FOR FUNCTION BASED VIEWS

   Normally, if a FBV defines a template_name parameter in the url, say "index.html", the view will lookup that template file via the normal template loader chain.

   However, the website_template_override() decorator will first try to lookup a url at "[website]/index.html" and then fall back to using the "index.html".

   /path/to/myproject/myapp/urls.py

    # Wrap a single url 
    
    urlpatterns = [
        url('^(?P<website>[\w-]+)/foo/$', 
            website_template_override(IndexView.as_view(
            template_name='index.html')), 
            {}, 
            name="app_foo_index"
        )
    ]
    
    # OR you can decorate an entire include
    
    urlpatterns += decorated_includes(website_template_override,
        patterns('', url(r'^(?P<website>[\w-]+)/bar/', 
                         include('example.app_bar.urls')))
    )
    
    # OR you can use both decorators at once on an entire include.
    urlpatterns += decorated_includes(
        (
            lambda func: enable_disable_website(func, BarConfig),
            website_template_override,
        ),
        patterns('', url(r'^(?P<website>[\w-]+)/bar/', 
                         include('example.app_bar.urls')))
    )
   

   You then need to accept the website variable as a keyword argument to your view function. The website variable can be used in your view logic.

   /path/to/myproject/myapp/views.py

    # Function based view example
    def index(request, template_name, website=None, *args, **kwargs):
        config = BarConfig(website=website)
        return render_to_response(template_name,
            {'config':config,},
            context_instance=RequestContext(request))
   

   FOR CLASS BASED VIEWS

   You should use the WebsiteOverrideTemplateViewMixin to allow for the template override behavior.

   /path/to/myproject/myapp/views.py

    from site_config.utils import WebsiteOverrideTemplateViewMixin
    from site_config.decorators import website_template_override
    from example.app_bar import BarConfig
    
    class IndexView(WebsiteOverrideTemplateViewMixin, TemplateView):
        
        def dispatch(self, request, *args, **kwargs):
            self.website = kwargs.get('website', None)
            self.config = BarConfig(website=self.website)
            return super(IndexView, self).dispatch(request, *args, **kwargs)
        
        def get_context_data(self, **kwargs):
            kwargs['config'] = self.config
            kwargs['website'] = self.website
            return kwargs
   

4. You can access settings in the view or template by calling the settings like you would an attribute on the config class.

   Here is a usage example:

   from example.app_foo import FooConfig
   c = FooConfig(website="joesite")
   c.TEST_A
   c.TEST_B
   

   Note: in order for the settings to be looked up dynamically (on each request), the config class must be instantiated inside the view with the proper website passed to the constructor (or None) on every request to the view.

TEMPLATE OVERRIDES

You can override the template below to customize the curtain page that displays when a Website Application as marked as "curtained". Note, the default template extends "base.html" so this will need to be present in your application.

site_config/curtained.html

TESTING

pip install -e .[testing]
cd example/
./manage.py test site_config