Implement Individual Map Widgets for Geometry Fields

[Paul Smith]

The form provided by GeoDjango for geometry fields (django.contrib.gis.forms.fields.GeometryField) is just a simple text box that accepts textual representations of geometries. The way admin currently generates its map forms is functional, but not really suited for general-purpose use. In particular, the map widget is generated dynamically by GeoModelAdmin.get_map_widget(). For better API consistency with the rest of Django, there should be reusable map editing widgets.

Because the geographic admin already uses ​OpenLayers, the default widgets should be written using it. It should be general enough to make supporting alternative geometry frameworks possible, however, OpenLayers support is the priority.

Doing this will hopefully make fixing related tickets, like #9806, easier.

[Paul Smith]

I think a design decision should be made about the inclusion of OpenLayers support, and for that matter Google Maps or Y! Maps support. It seems like these libraries should be treated the same way as Ajax support has been for Django, that is, out-of-band of the framework. It's arguable that for mapping application, a special case could be made in order to get a simple map up quickly with the KML from the models, which both GMaps and OpenLayers support. In that case, it seems a template tag may be more appropriate.

[jbronn]

Replying to p:

It seems like these libraries should be treated the same way as Ajax support has been for Django, that is, out-of-band of the framework. It's arguable that for mapping application, a special case could be made in order to get a simple map up quickly with the KML from the models, which both !GMaps and OpenLayers support.

But we want widgets for the admin and databrowse -- how can these be supported without support for any mapping framework built-in? I agree the feature-set should be minimal but still should be present -- users may then customize and/or extend the JavaScript templates at their discretion, and widgets may be created in the admin and databrowse.

We would not be playing to Django's strength's by excluding any sort of mapping framework.

In that case, it seems a template tag may be more appropriate.

I think it will be very difficult to shoehorn all map creation options into a template tag -- it seems more appropriate to have an object with that type of detail instantiated in the views, and passed into the template.

[springmeyer]

OpenLayers support was added as a built in feature of the admin in r7980.

Should this be closed and re-opened as a ticket for discussion how to integration the OL js into the framework outside the admin?

[christian@…]

I'm working on a project called "​OpenWebGIS" (demo:demo) and using OpenLayers to display and manage Features.
There is also a project called "​olwidget".