django-layar

Django generic view for making Layar endpoints.

Provides abstract class that responds to Layar API requests in the appropriate format. By implementing two small functions it is possible to add a layer to the Layar augmented reality application for Android and iPhone.

django-layar is a project of Sunlight Labs (c) 2009. Written by James Turk <jturk@sunlightfoundation.com>

Source: http://github.com/sunlightlabs/django-layar/

Documentation: http://packages.python.org/django-layar/README.html

Requirements

python >= 2.4

django >= 1.0

Usage

Layar Developer Key

If you haven’t already, it is necessary to sign up with Layar to obtain an API key.

Set LAYAR_DEVELOPER_KEY='<YOUR_KEY>' in settings.py

Creating a LayarView subclass

django-layar provides a class-based generic view at layar.LayarView. In order to provide your own layers it is necessary to inherit from this view and implement two simple functions (per layer).

The required functions are get_LAYERNAME_queryset() and poi_from_LAYERNAME_item().

It is possible to serve as many layers as you desire from a single Layar endpoint, just make sure that the name of your functions matches the name you provide when registering your layers with Layar.com

get_LAYERNAME_queryset() is passed a number of arguments (see layar.LayarView for detail) and should return a queryset of the objects for LayarView to paginate and return.

poi_from_LAYERNAME_item() is called on each item being returned, and should convert items into layar.POI objects.

It is usually best to then create an instance of your derived class in your application’s views.py

Example:

# views.py

from django.contrib.gis.geos import Point
from myapp.models import BusStop
from layar import LayarView, POI

class BusStopLayar(LayarView):

    # make sure to accept **kwargs
    def get_busstop_queryset(self, latitude, longitude, radius, **kwargs):
        return BusStop.objects.filter(location__distance_lt=(Point(longitude, latitude), radius))

    def poi_from_recoverygov_item(self, item):
        return POI(id=item.id, lat=item.location.y, lon=item.location.x, title=item.name,
                    line2=item.route_name, line3='Distance: %distance%')

# create an instance of BusStopLayar
busstop_layar = BusStopLayar()

In urls.py it is then necessary to map a URL directly to busstop_layar:

# urls.py

from django.conf.urls.defaults import *

urlpatterns = patterns('',
    url(r'^layar_endpoint/$', 'myapp.views.busstop_layar'),
)

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