Django Google Maps form widget

Django Google Maps form widget(회전)
We’re building a Django application at work, and I had to implement a way for a user to select a location on a map, in order to be able to save the exact coordinates and the zoom level the user chose. I looked around to see if something similar had been developed, but I did not find anything so simple and useful as what I later developed, so for the sake of open source-ness I’m sharing it here with you. It is implemented as a standard Django form widget so just do as any other Django widget, for example:

class PersonForm(forms.Form):

name = forms.CharField()

website = forms.URLField()

location = forms.CharField(widget=GMapInput(attrs={'width':'600', 'height':'400'}))

Here’s the code for the GMapInput class (sorry for the docs in Spanish, but I’m in Mexico):

from django.forms.widgets import Input

from django.utils.safestring import mark_safe

 

class GMapInput(Input):

"""

Widget para seleccionar un punto en un mapa de Google

"""

 

def render(self, name, value, attrs=None):

"""

Atributos extras:

- width: ancho del mapa en pixeles

- height: alto del mapa en pixeles

- center: latitud,longitud del punto central del mapa

- zoom: zoom inicial del mapa, 1 - 17

"""

 

final_attrs = self.build_attrs(attrs)

width = final_attrs['width'] if 'width' in final_attrs else '500'

height = final_attrs['height'] if 'height' in final_attrs else '300'

center = final_attrs['center'] if 'center' in final_attrs else '21.983801,-100.964355' # Centro de México

zoom = final_attrs['zoom'] if 'zoom' in final_attrs else '4' # Zoom amplio, se ve todo un país

 

widget = u'''<div style="margin-left:7em; padding-left:30px;">

<input type="hidden" value="%(value)s" name="%(name)s" id="%(id)s" />

<div id="%(id)s_map" style="width: %(width)spx; height: %(height)spx"></div></div>

<script type="text/javascript">

var %(id)s_map = new GMap2(document.getElementById("%(id)s_map"));

%(id)s_map.addControl(new GLargeMapControl3D());

 

var %(id)s_marker;

function %(id)s_updateField() {

document.getElementById("%(id)s").value = %(id)s_marker.getLatLng().toUrlValue() + "|" + %(id)s_map.getZoom();

%(id)s_map.panTo(%(id)s_marker.getLatLng(), true);

}

''' % { 'value': value, 'name': name, 'id': final_attrs['id'], 'width': width, 'height': height }

 

if value is None or value == '':

widget = widget + u'''

%(id)s_map.setCenter(new GLatLng(%(center)s), %(zoom)s);

var %(id)s_clickListener = GEvent.addListener(%(id)s_map, "click", function(overlay, latlng) {

if(latlng) {

%(id)s_marker = new GMarker(latlng, {draggable: true});

%(id)s_map.addOverlay(%(id)s_marker);

%(id)s_updateField();

 

GEvent.addListener(%(id)s_marker, "dragend", %(id)s_updateField);

GEvent.addListener(%(id)s_map, "zoomend", %(id)s_updateField);

GEvent.addListener(%(id)s_map, "dblclick", function (overlay, latlng) { %(id)s_marker.setLatLng(latlng); %(id)s_updateField(); });

GEvent.removeListener(%(id)s_clickListener);

}

});

</script>''' % { 'id': final_attrs['id'], 'center': center, 'zoom': zoom }

else:

values = value.partition('|')

 

widget = widget + u'''

%(id)s_map.setCenter(new GLatLng(%(coords)s), %(zoom)s);

%(id)s_marker = new GMarker(new GLatLng(%(coords)s), {draggable: true});

%(id)s_map.addOverlay(%(id)s_marker);

 

GEvent.addListener(%(id)s_marker, "dragend", %(id)s_updateField);

GEvent.addListener(%(id)s_map, "zoomend", %(id)s_updateField);

GEvent.addListener(%(id)s_map, "dblclick", function (overlay, latlng) { %(id)s_marker.setLatLng(latlng); %(id)s_updateField(); });

''' % { 'id': final_attrs['id'], 'coords': values[0], 'zoom': values[2] }

 

return mark_safe(widget)

Don’t forget to add the tag linking to the Google Maps API.
It is yet far from perfect, but I still hope it helps someone out there.