Pluggable geocoder in feature_list.js

[sweco-semtne]

We are using Pelias as a geocoder over openstreetmap data and would like to extract the functionality in feature_list.js to be able to use a pluggable geocoder instead of directly calling nominatim.
I'm thinking that it could be a service that can be setup in the context in the same way as the nominatim service.

A simple API like the one below could be enough

function geocode(searchTerm, callback) {}

The simplest way to do introduce this would be to:

• Introduce new service geocode with the api above (model the response after Nominatim)
• Import service in feature_list.js
• Change the eventlistener in feature_list.js to call imported service

I know that nominatim is more or less the standard but it would be nice to be pluggable in this regard and I don't think it would be intrusive to the users in any way. The default service would of course be Nominatim.

[bhousel]

Good suggestion, I agree...

[sweco-semtne]

Could the current nominatim service be used if we add a function geocode?
In feature_list.js

 import { services } from '../services/index';
 ...
 function geocode() {
            services.nominatim.geocode(search.property('value'), function(resp) {
                geocodeResults = resp;
                drawList();
            });
        }

And in nominatim.js

var endpoint = 'https://nominatim.openstreetmap.org/', 
   nominatimCache;

   ...
   geocode: function(value, callback) {
        var searchVal = encodeURIComponent(value);
        d3.json(endpoint + 'search/' + searchVal + '?limit=10&format=json', function(err, resp) {
            callback(resp || []);
        });
    }

[sweco-semtne]

Btw, what's the correct/best way of making a service pluggable for the developer without modifying the library code?

[bhousel]

Everything in the services module is designed to be swappable at runtime. See API.md#services

So after we fix the issues in this ticket, it should ideally be as easy as a line like this before your page initializes the iD context object.

iD.services.geocoder = replacementService;

[sweco-semtne]

Great! And I just want to thank you for the great work you and everyone else that has contributed to iD has done!