def find_locations_in_radius(request):
"""
Determines the coordinates of the input address and finds all active
locations within the specified radius. The results are returned as a JSON
object.
"""
# This view should only be requested via an HTTP POST + XHR request
if not (request.method == 'POST' and request.is_ajax()):
raise Http404
json = JSONEncoder()
# snag some needed info from the request
address = request.POST.get('address', '')
radius = float(request.POST.get('radius', 25))
try:
# TODO: figure out how to make this better when more than one result
# is retrieved
coords = utils.get_coordinates(address=address)
except StopIteration:
# this happens if no matches were found
err = {'error': 'Please enter a valid location!'}
return render_to_response('reploc/json.js',
{'json': json.encode(err)})
lat1, lng1 = float(coords[0]), float(coords[1])
# put stuff into a dictionary
data = {'center': {
'address': address,
'lat': lat1,
'lng': lng1
},
'locations': []}
# this number is used a lot. I'm not math wiz, so I have no idea what it's
# used for, but my guess is that it has something to do with trig (which I
# conveniently skipped in school)
C = 57.2958
# iterate over all active locations
for location in Location.objects.active():
lat2, lng2 = location.coordinates
# check the distance between the center and the location
# source: http://www.meridianworlddata.com/Distance-Calculation.asp
dist = 3963.189 * acos(sin(lat1 / C) * sin(lat2 / C) + cos(lat1 / C) \
* cos(lat2 / C) * cos(lng2 / C - lng1 / C))
# if the location is within the radius of the input address, add it to
# our collection
if dist <= radius:
data['locations'].append(jsonify_location(location))
# send everything back as a JSON object
return render_to_response('reploc/json.js',
{'json': json.encode(data)},
mimetype='text/javascript')
def get_locations(request):
"""
Retrieves all locations for all active representatives and returns the
collection as a JSON object.
"""
locations = Location.objects.active()
json = JSONEncoder()
data = {'locations': [jsonify_location(l) for l in locations]}
return render_to_response('reploc/json.js',
{'json': json.encode(data)},
mimetype='text/javascript')