Fixes #341: Added highlight_function functionality for choropleth maps

Author: joshuacano

folium/features.py

@@ -297,7 +297,8 @@ class GeoJson(Layer):
     >>> GeoJson(geojson, style_function=style_function)
     """
     def __init__(self, data, style_function=None, name=None,
-                 overlay=True, control=True, smooth_factor=None):
+                 overlay=True, control=True, smooth_factor=None,
+                 highlight_function=None):
         super(GeoJson, self).__init__(name=name, overlay=overlay,
                                       control=control)
         self._name = 'GeoJson'
@@ -333,16 +334,45 @@ def style_function(x):
                 return {}
         self.style_function = style_function
 
+        self.highlight_function = highlight_function
+
         self.smooth_factor = smooth_factor
 
         self._template = Template(u"""
             {% macro script(this, kwargs) %}
+            
+            {% if this.highlight_function is not none %}
+                {{this.get_name()}}_onEachFeature = function onEachFeature(feature, layer) {
+                    layer.on({
+                        mouseout: function(e) {
+                            e.target.setStyle(e.target.feature.properties.style);},
+                        mouseover: function(e) {
+                            e.target.setStyle(e.target.feature.properties.highlight);},
+                        click: function(e) {
+                            {{this._parent.get_name()}}.fitBounds(e.target.getBounds());}
+                        });
+                };
+            {% endif %}
+
                 var {{this.get_name()}} = L.geoJson(
                     {% if this.embed %}{{this.style_data()}}{% else %}"{{this.data}}"{% endif %}
-                    {% if this.smooth_factor is not none %}
-                        , {smoothFactor:{{this.smooth_factor}}}
-                    {% endif %}).addTo({{this._parent.get_name()}});
+                    {% if this.smooth_factor is not none or this.highlight_function is not none %}
+                        , {
+                        {% if this.smooth_factor is not none  %}
+                            smoothFactor:{{this.smooth_factor}}}
+                        {% endif %}
+                    
+                        {% if this.highlight_function is not none %}
+                            {% if this.smooth_factor is not none  %}
+                            ,
+                            {% endif %}
+                            onEachFeature: {{this.get_name()}}_onEachFeature
+                        {% endif %}
+                        }
+                    {% endif %}
+                    ).addTo({{this._parent.get_name()}});
                 {{this.get_name()}}.setStyle(function(feature) {return feature.properties.style;});
+
             {% endmacro %}
             """)  # noqa
 
@@ -361,6 +391,7 @@ def style_data(self):
 
         for feature in self.data['features']:
             feature.setdefault('properties', {}).setdefault('style', {}).update(self.style_function(feature))  # noqa
+            feature.setdefault('properties', {}).setdefault('highlight', {}).update(self.highlight_function(feature))  # noqa
         return json.dumps(self.data, sort_keys=True)
 
     def _get_self_bounds(self):

folium/folium.py

@@ -22,15 +22,13 @@
                        ClickForMarker, TopoJson, PolyLine, MultiPolyLine,
                        )
 
-
 def initialize_notebook():
     """Initialize the IPython notebook display elements."""
     warnings.warn("%s is deprecated and no longer required." %
                   ("initialize_notebook",),
                   FutureWarning, stacklevel=2)
     pass
 
-
 class Map(LegacyMap):
     """Create a Map with Folium and Leaflet.js
 
@@ -673,12 +671,18 @@ def color_scale_fun(x):
         def style_function(x):
             return {
                 "weight": line_weight,
-                "opactiy": line_opacity,
+                "opacity": line_opacity,
                 "color": line_color,
                 "fillOpacity": fill_opacity,
                 "fillColor": color_scale_fun(x)
             }
 
+        def highlight_function(x):
+            return {
+                "weight": line_weight + 2,
+                "fillOpacity": fill_opacity + .2
+            }
+
         if topojson:
             geo_json = TopoJson(
                 geo_data,
@@ -689,7 +693,8 @@ def style_function(x):
             geo_json = GeoJson(
                 geo_data,
                 style_function=style_function,
-                smooth_factor=smooth_factor)
+                smooth_factor=smooth_factor,
+                highlight_function=highlight_function)
 
         self.add_child(geo_json)
 

folium/map.py

@@ -22,7 +22,7 @@
 
 _default_js = [
     ('leaflet',
-     "https://cdnjs.cloudflare.com/ajax/libs/leaflet/0.7.3/leaflet.js"),
+     "https://npmcdn.com/leaflet@1.0.0-rc.3/dist/leaflet.js"),
     ('jquery',
      "https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"),
     ('bootstrap',
@@ -37,7 +37,7 @@
 
 _default_css = [
     ("leaflet_css",
-     "https://cdnjs.cloudflare.com/ajax/libs/leaflet/0.7.3/leaflet.css"),
+     "https://npmcdn.com/leaflet@1.0.0-rc.3/dist/leaflet.css"),
     ("bootstrap_css",
      "https://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css"),
     ("bootstrap_theme_css",