django-mobile provides a simple way to detect mobile browsers and gives you tools at your hand to render some different templates to deliver a mobile version of your site to the user.
The idea is to keep your views exactly the same but to transparently interchange the templates used to render a response. This is done in two steps:
- A middleware determines the client's preference to view your site. E.g. if he wants to use the mobile flavour or the full desktop flavour.
- The template loader takes then care of choosing the correct templates based on the flavour detected in the middleware.
Pre-Requirements: django_mobile depends on django's session framework. So
before you try to use django_mobile make sure that the sessions framework
is enabled and working.
- Install
django_mobilewith your favourite python tool, e.g. witheasy_install django_mobileorpip install django_mobile. - Add
django_mobileto yourINSTALLED_APPSsetting in thesettings.py. - Add
django_mobile.middleware.MobileDetectionMiddlewareto yourMIDDLEWARE_CLASSESsetting. - Add
django_mobile.middleware.SetFlavourMiddlewareto yourMIDDLEWARE_CLASSESsetting. Make sure it's listed afterMobileDetectionMiddlewareand also afterSessionMiddleware. - Add
django_mobile.loader.Loaderas first item to yourloaderslist forTEMPLATESsetting insettings.py. - Add
django_mobile.context_processors.flavourto yourcontext_processorslist forTEMPLATESsetting. You can read more aboutloadersandcontext_processorsin Django docs.
Now you should be able to use django-mobile in its glory. Read below of how things work and which settings can be tweaked to modify django-mobile's behaviour.
The concept of django-mobile is build around the ideas of different flavours for your site. For example the mobile version is described as one possible flavour, the desktop version as another.
This makes it possible to provide many possible designs instead of just differentiating between a full desktop experience and one mobile version. You can make multiple mobile flavours available e.g. one for mobile safari on the iPhone and Android as well as one for Opera and an extra one for the internet tablets like the iPad.
Note: By default django-mobile only distinguishes between full and mobile flavour.
After the correct flavour is somehow chosen by the middlewares, it's
assigned to the request.flavour attribute. You can use this in your views
to provide separate logic.
This flavour is then use to transparently choose custom templates for this
special flavour. The selected template will have the current flavour prefixed
to the template name you actually want to render. This means when
render_to_response('index.html', ...) is called with the mobile flavour
being active will actually return a response rendered with the
mobile/index.html template. However if this flavoured template is not
available it will gracefully fallback to the default index.html template.
In some cases its not the desired way to have a completely separate templates
for each flavour. You can also use the {{ flavour }} template variable to
only change small aspects of a single template. A short example:
<html>
<head>
<title>My site {% if flavour == "mobile" %}(mobile version){% endif %}</title>
</head>
<body>
...
</body>
</html>This will add (mobile version) to the title of your site if viewed with
the mobile flavour enabled.
Note: The flavour template variable is only available if you have set up the
django_mobile.context_processors.flavour context processor.
The basic use case of django-mobile is obviously to serve a mobile version
of your site to users. The selection of the correct flavour is usually already
done in the middlewares when your own views are called. In some cases you want
to change the currently used flavour in your view or somewhere else. You can
do this by simply calling django_mobile.set_flavour(flavour[,
permanent=True]). The first argument is self explaining. But keep in mind
that you only can pass in a flavour that you is also in your FLAVOURS
setting. Otherwise set_flavour will raise a ValueError. The optional
permanent parameters defines if the change of the flavour is remember for
future requests of the same client.
Your users can set their desired flavour them self. They just need to specify
the flavour GET parameter on a request to your site. This will permanently
choose this flavour as their preference to view the site.
You can use this GET parameter to let the user select from your available flavours:
<ul>
<li><a href="?flavour=full">Get the full experience</a>
<li><a href="?flavour=mobile">View our mobile version</a>
<li><a href="?flavour=ipad">View our iPad version</a>
</ul>Django is shipping with some convenience methods to easily cache your views.
One of them is django.views.decorators.cache.cache_page. The problem with
caching a whole page in conjunction with django-mobile is, that django's
caching system is not aware of flavours. This means that if the first request
to a page is served with a mobile flavour, the second request might also
get a page rendered with the mobile flavour from the cache -- even if the
second one was requested by a desktop browser.
django-mobile is shipping with it's own implementation of cache_page
to resolve this issue. Please use django_mobile.cache.cache_page instead
of django's own cache_page decorator.
You can also use django's caching middlewares
django.middleware.cache.UpdateCacheMiddleware and
FetchFromCacheMiddleware like you already do. But to make them aware of
flavours, you need to add
django_mobile.cache.middleware.FetchFromCacheFlavourMiddleware item before standard Django FetchFromCacheMiddleware
in the MIDDLEWARE_CLASSES settings and django_mobile.cache.middleware.UpdateCacheFlavourMiddleware before
django_mobile.cache.middleware.UpdateCacheMiddleware correspondingly.
It is necessary to split the usage of CacheMiddleware because some additional work should be done on request and response before standard caching behavior and that is not possible while using two complete middlewares in either order
django_mobile.get_flavour([request,] [default])- Get the currently active flavour. If no flavour can be determined it will
return default. This can happen if
set_flavourwas not called before in the current request-response cycle. default defaults to the first item in theFLAVOURSsetting. django_mobile.set_flavour(flavour, [request,] [permanent])- Set the flavour to be used for request. This will raise
ValueErrorif flavour is not in theFLAVOURSsetting. You can try to set the flavour permanently for request by passingpermanent=True. This may fail if you are out of a request-response cycle. request defaults to the currently active request. django_mobile.context_processors.flavour- Context processor that adds the current flavour as flavour to the context.
django_mobile.context_processors.is_mobile- This context processor will add a is_mobile variable to the context
which is
Trueif the current flavour equals theDEFAULT_MOBILE_FLAVOURsetting. django_mobile.middleware.SetFlavourMiddleware- Takes care of loading the stored flavour from the user's session or
cookies (depending on
FLAVOURS_STORAGE_BACKEND) if set. Also sets the current request to a thread-local variable. This is needed to provideget_flavour()functionality without having access to the request object. django_mobile.middleware.MobileDetectionMiddleware- Detects if a mobile browser tries to access the site and sets the flavour
to
DEFAULT_MOBILE_FLAVOURsettings value in case. django_mobile.cache.cache_page- Same as django's
cache_pagedecorator, but wraps the view into additional decorators before and after that. Makes it possible to serve multiple flavours without getting into trouble with django's caching that doesn't know about flavours. django_mobile.cache.vary_on_flavour_fetchdjango_mobile.cache.vary_on_flavour_update- Decorators created from the
FetchFromCacheFlavourMiddlewareandUpdateCacheFlavourMiddlewaremiddleware. django_mobile.cache.middleware.FetchFromCacheFlavourMiddleware- Adds
X-Flavourheader torequest.METAinprocess_request django_mobile.cache.middleware.UpdateCacheFlavourMiddleware- Adds
X-Flavourheader toresponse['Vary']inprocess_responseso that Django'sCacheMiddlewareknow that it should take into account the content of this header when looking up the cached content on next request to this URL.
There are some points available that let you customize the behaviour of django-mobile. Here are some possibilities listed:
The built-in middleware to detect if the user is using a mobile browser served
well in production but is far from perfect and also implemented in a very
simplistic way. You can safely remove this middleware from your settings and
add your own version instead. Just make sure that it calls
django_mobile.set_flavour at some point to set the correct flavour for
you.
If you need example how tablet detection can be implemented, you can checkout the middleware.py file in directory examples. Feel free to modify it as you like!
Here is a list of settings that are used by django-mobile and can be
changed in your own settings.py:
FLAVOURSA list of available flavours for your site.
Default:
('full', 'mobile')DEFAULT_MOBILE_FLAVOURThe flavour which is chosen if the built-in
MobileDetectionMiddlewaredetects a mobile browser.Default:
'mobile'FLAVOURS_COOKIE_HTTPONLYThe value that get passed into
HttpResponse.set_cookie'shttponlyargument. Set this toTrueif you don't want the Javascript code to be able to read the flavour cookie.Default:
FalseFLAVOURS_COOKIE_KEYThe cookie name that is used for storing the selected flavour in the browser. This is only used if
FLAVOURS_STORAGE_BACKENDis set to'cookie'.Default:
'flavour'FLAVOURS_TEMPLATE_PREFIXThis string will be prefixed to the template names when searching for flavoured templates. This is useful if you have many flavours and want to store them in a common subdirectory. Example:
from django.template.loader import render_to_string from django_mobile import set_flavour set_flavour('mobile') render_to_string('index.html') # will render 'mobile/index.html' # now add this to settings.py FLAVOURS_TEMPLATE_PREFIX = 'flavours/' # and try again set_flavour('mobile') render_to_string('index.html') # will render 'flavours/mobile/index.html'
Default:
''(empty string)FLAVOURS_TEMPLATE_LOADERSdjango-mobile's template loader can load templates prefixed with the current flavour. Specify with this setting which loaders are used to load flavoured templates.
Default: same as
TEMPLATE_LOADERSsetting but without'django_mobile.loader.Loader'.FLAVOURS_GET_PARAMETERUsers can change the flavour they want to look at with a HTTP GET parameter. This determines the name of this parameter. Set it to
Noneto disable.Default:
'flavour'FLAVOURS_SESSION_KEYThe user's preference set with the GET parameter is stored in the user's session. This setting determines which session key is used to hold this information.
Default:
'flavour'FLAVOURS_STORAGE_BACKENDDetermines how the selected flavour is stored persistently. Available values:
'session'and'cookie'.Default:
'cookie'
Django ships with the cached template loader
django.template.loaders.cached.Loader that doesn't require to fetch the
template from disk every time you want to render it. However it isn't aware of
django-mobile's flavours. For this purpose you can use
'django_mobile.loader.CachedLoader' as a drop-in replacement that does
exactly the same django's version but takes the different flavours into
account. To use it, put the following bit into your settings.py file:
TEMPLATES = [
{
...
'OPTIONS': {
...
'loaders': ('django_mobile.loader.CachedLoader', (
'django_mobile.loader.Loader',
'django.template.loaders.filesystem.Loader',
'django.template.loaders.app_directories.Loader',
)),
}
}
]