Better geocoding support

With mapping websites becoming increasingly global in nature, the current model for linking to maps from Drupal using the location.module starts to become unmanageable. At the moment each country must have its own functionality to link to maps and there is no overall linking mechanism.

Google Maps displays street maps for the US, Canada, much of Europe (UK, France, Germany, Italy, Spain, Portugal, Austria, Switzerland, Lichtenstein, Belgium, Netherlands, Sweden, Norway, Finland, Andorra, Czech Republic, Slovakia, Poland, Hungary, Greece, Turkey, and probably a few more), Japan, Australia and New Zealand. In addition to the maps, they have satellite coverage for the whole globe. Other mapping providers such as Ask.com maps, Microsoft Live Local and Yahoo maps have similar coverage.

In terms of the current architecture, if a site wants to be able to link to maps from each of these four providers for each of the countries supported by these mapping sites, there would be a lot of duplication and perhaps only minor changes between the linking options. The benefit is that you can choose the address format and options that you use to link to the site by changing the code; this is useful because different map providers accept different combinations of input (eg, include the country name in a Ask.com query and the result will not be returned, but use only the city name and it will work) and each country has slightly different addressing formats.

To build upon the map linking options that we currently have in the location.module, I would like to propose some improvements, some of which were suggested in #25086 before the then hard links to Yahoo were made to be more flexible.

1. Centre the map link functionality on map providers, not countries. For each map provider, functions should exist to produce the following:
   • a link using address information in a relatively standard format for use across different countries (eg street, city, postal code, country)
   • a link using coordinate information
2. Allow for users to choose whether to link to map using address information or coordinate information. This should be on a country level, per mapping provider, to take into account different levels of mapping information and linking options available for each country in each mapping provider.
3. Allow address format to be customized on a per-country, per-mapping provider basis.

I'd suggest displaying a list of countries down the left hand side of a grid, map providers across the top, and for each country/provider combination you have a dropdown that lets you select whether you link to it using the address, using the latitude and longitude, or not at all. There could be then a link to customise address format, if absolutely necessary.

Comments, suggestions, anyone?