expanding Geocoder plugin to support other built-in providers supported by leaflet-control-geocoder

also allows for user-defined geocode providers

Author: prusswan

folium/plugins/geocoder.py

@@ -19,6 +19,16 @@ class Geocoder(JSCSSMixin, MacroElement):
         Choose from 'topleft', 'topright', 'bottomleft' or 'bottomright'.
     add_marker: bool, default True
         If True, adds a marker on the found location.
+    geocodeProvider: str, default 'nominatim'
+        see https://github.com/perliedman/leaflet-control-geocoder/tree/2.4.0/src/geocoders for other built-in providers
+    geocodeProviderOptions: dict, default None
+        For use with specific providers that may require api keys or other parameters
+    serviceUrl: str, default None
+        For use with user-defined geocode provider. If used, geocodeFunction must also be specified, geocodeProvider param will be ignored.
+    geocodeFunction: str, default None
+        geocode function of user-defined geocode provider. see https://github.com/perliedman/leaflet-control-geocoder/blob/1.13.0/src/geocoders/nominatim.js for a reference implementation
+    resultsHandlerFunction: str, default None
+        For use with user-defined geocode provider, to format geocoding responses into the format expected by leaflet-control-geocoder. Each result should have 'name','center' (L.latLng),'bbox' (L.latLngBounds) properties. see https://github.com/perliedman/leaflet-control-geocoder/blob/1.13.0/src/geocoders/photon.js (_decodeFeatures) for a reference implementation
 
     For all options see https://github.com/perliedman/leaflet-control-geocoder
 
@@ -27,8 +37,103 @@ class Geocoder(JSCSSMixin, MacroElement):
     _template = Template(
         """
         {% macro script(this, kwargs) %}
+
+            var geocoderOpts_{{ this.get_name() }} = {{ this.options|tojson }};
+            if ('geocodeFunction' in geocoderOpts_{{ this.get_name() }}) {
+                eval("geocoderOpts_{{ this.get_name() }}['geocodeFunction'] = " + geocoderOpts_{{ this.get_name() }}['geocodeFunction']);
+            }
+            if ('resultsHandlerFunction' in geocoderOpts_{{ this.get_name() }}) {
+                eval("geocoderOpts_{{ this.get_name() }}['resultsHandlerFunction'] = " + geocoderOpts_{{ this.get_name() }}['resultsHandlerFunction']);
+            }
+            var customGeocoderTemplate_{{ this.get_name() }} = {
+                class: L.Class.extend({
+                    options: {
+                        serviceUrl: geocoderOpts_{{ this.get_name() }}['serviceUrl'],
+                        geocodingQueryParams:  geocoderOpts_{{ this.get_name() }}['geocodingQueryParams'] || {},
+                        reverseQueryParams: geocoderOpts_{{ this.get_name() }}['reverseQueryParams'] || {},
+                    },
+
+                    initialize: function(options) {
+                        L.Util.setOptions(this, options || {});
+                    },
+
+                    geocode: geocoderOpts_{{ this.get_name() }}['geocodeFunction'],
+
+                    suggest: function(query,cb,context) {
+                        return this.geocode(query, cb, context);
+                    },
+
+                    // placeholder: not used by folium.plugin.Geocoder
+                    reverse: function(location, scale, cb, context) {
+                      var params = L.extend(
+                        {
+                          //defaultParam: defaultParamValue
+                        },
+                        this.options.reverseQueryParams
+                      );
+
+                      this.getJSON(
+                        this.options.serviceUrl + 'reverse',
+                        params,
+                        L.bind(function(data) {
+                          cb.call(context, this._resultsHandler(data));
+                        }, this)
+                      );
+                    },
+
+                    _resultsHandler: function(data) {
+                        if ('resultsHandlerFunction' in geocoderOpts_{{ this.get_name() }}) {
+                            return geocoderOpts_{{ this.get_name() }}['resultsHandlerFunction'](data);
+                        }
+                        return data;
+                    },
+
+                    getJSON: function(url, params, callback) {
+                        var xmlHttp = new XMLHttpRequest();
+                        xmlHttp.onreadystatechange = function () {
+                            if (xmlHttp.readyState !== 4){
+                                return;
+                            }
+                            if (xmlHttp.status !== 200 && xmlHttp.status !== 304){
+                                callback('');
+                                return;
+                            }
+                            callback(JSON.parse(xmlHttp.response));
+                        };
+                        xmlHttp.open('GET', url + L.Util.getParamString(params), true);
+                        xmlHttp.setRequestHeader('Accept', 'application/json');
+                        xmlHttp.send(null);
+                    }
+
+                }),
+
+                factory: function(options) {
+                    return new L.Control.Geocoder.Custom_{{ this.get_name() }}(options);
+                },
+
+            }
+
+            L.Util.extend(L.Control.Geocoder, {
+                Custom_{{ this.get_name() }}: customGeocoderTemplate_{{ this.get_name() }}.class,
+                custom_{{ this.get_name() }}: customGeocoderTemplate_{{ this.get_name() }}.factory
+            });
+
+            // use lowercase for geocoder name
+            var geocoderName_{{ this.get_name() }};
+            if ('serviceUrl' in geocoderOpts_{{ this.get_name() }}) {
+                geocoderName_{{ this.get_name() }} = 'custom_{{ this.get_name() }}';
+            }
+            else {
+                geocoderName_{{ this.get_name() }} = geocoderOpts_{{ this.get_name() }}["geocodeProvider"];
+            }
+
+            var customGeocoder_{{ this.get_name() }} = L.Control.Geocoder[ geocoderName_{{ this.get_name() }} ](
+                geocoderOpts_{{ this.get_name() }}['geocodeProviderOptions']
+            );
+            geocoderOpts_{{ this.get_name() }}["geocoder"] = customGeocoder_{{ this.get_name() }};
+
             L.Control.geocoder(
-                {{ this.options|tojson }}
+                geocoderOpts_{{ this.get_name() }}
             ).on('markgeocode', function(e) {
                 {{ this._parent.get_name() }}.setView(e.geocode.center, 11);
             }).addTo({{ this._parent.get_name() }});
@@ -50,12 +155,24 @@ class Geocoder(JSCSSMixin, MacroElement):
         )
     ]
 
-    def __init__(self, collapsed=False, position="topright", add_marker=True, **kwargs):
+    def __init__(self, collapsed=False, position="topright", add_marker=True,
+                 geocodeProvider="nominatim",
+                 geocodeProviderOptions=None,
+                 serviceUrl=None,
+                 geocodeFunction=None,
+                 resultsHandlerFunction=None,
+                 **kwargs):
         super().__init__()
         self._name = "Geocoder"
         self.options = parse_options(
             collapsed=collapsed,
             position=position,
             defaultMarkGeocode=add_marker,
+            geocodeProvider=geocodeProvider,
+            serviceUrl=serviceUrl,
+            geocodeFunction=geocodeFunction,
+            resultsHandlerFunction=resultsHandlerFunction,
             **kwargs
         )
+        if geocodeProviderOptions is not None:
+            self.options['geocodeProviderOptions'] = geocodeProviderOptions