Implement _get_self_bounds for GeoJson, Polyline...

Author: Martin Journois

folium/features.py

@@ -10,7 +10,9 @@
 
 from .utilities import (color_brewer, _parse_size, legend_scaler,
                         _locations_mirror, _locations_tolist, image_to_url,
-                        text_type, binary_type)
+                        text_type, binary_type,
+                        none_min, none_max, iter_points,
+                        )
 
 from .element import Element, Figure, JavascriptLink, CssLink, MacroElement
 from .map import Layer, Icon, Marker, Popup
@@ -280,7 +282,30 @@ def _get_self_bounds(self):
         """Computes the bounds of the object itself (not including it's children)
         in the form [[lat_min, lon_min], [lat_max, lon_max]]
         """
-        raise NotImplementedError
+        if not self.embed:
+            raise ValueError('Cannot compute bounds of non-embedded GeoJSON.')
+
+        if 'features' not in self.data.keys():
+            # Catch case when GeoJSON is just a single Feature or a geometry.
+            if not (isinstance(self.data, dict) and 'geometry' in self.data.keys()):
+                # Catch case when GeoJSON is just a geometry.
+                self.data = {'type' : 'Feature', 'geometry' : self.data}
+            self.data = {'type' : 'FeatureCollection', 'features' : [self.data]}
+
+        bounds = [[None,None],[None,None]]
+        for feature in self.data['features']:
+            for point in iter_points(feature.get('geometry',{}).get('coordinates',{})):
+                bounds = [
+                    [
+                        none_min(bounds[0][0], point[1]),
+                        none_min(bounds[0][1], point[0]),
+                        ],
+                    [
+                        none_max(bounds[1][0], point[1]),
+                        none_max(bounds[1][1], point[0]),
+                        ],
+                    ]
+        return bounds
 
 class TopoJson(MacroElement):
     def __init__(self, data, object_path):
@@ -584,7 +609,19 @@ def _get_self_bounds(self):
         """Computes the bounds of the object itself (not including it's children)
         in the form [[lat_min, lon_min], [lat_max, lon_max]]
         """
-        raise NotImplementedError
+        bounds = [[None,None],[None,None]]
+        for point in iter_points(self.data):
+            bounds = [
+                [
+                    none_min(bounds[0][0], point[0]),
+                    none_min(bounds[0][1], point[1]),
+                ],
+                [
+                    none_max(bounds[1][0], point[0]),
+                    none_max(bounds[1][1], point[1]),
+                ],
+            ]
+        return bounds
 
 class MultiPolyLine(MacroElement):
     def __init__(self, locations, color=None, weight=None,
@@ -636,7 +673,19 @@ def _get_self_bounds(self):
         """Computes the bounds of the object itself (not including it's children)
         in the form [[lat_min, lon_min], [lat_max, lon_max]]
         """
-        raise NotImplementedError
+        bounds = [[None,None],[None,None]]
+        for point in iter_points(self.data):
+            bounds = [
+                [
+                    none_min(bounds[0][0], point[0]),
+                    none_min(bounds[0][1], point[1]),
+                ],
+                [
+                    none_max(bounds[1][0], point[0]),
+                    none_max(bounds[1][1], point[1]),
+                ],
+            ]
+        return bounds
 
 class CustomIcon(Icon):
     def __init__(self, icon_image, icon_size=None, icon_anchor=None,

folium/map.py

@@ -167,12 +167,6 @@ def add_tile_layer(self, tiles='OpenStreetMap', name=None,
                                detect_retina=detect_retina)
         self.add_children(tile_layer, name=tile_layer.tile_name)
 
-    def _get_self_bounds(self):
-        """Computes the bounds of the object itself (not including it's children)
-        in the form [[lat_min, lon_min], [lat_max, lon_max]]
-        """
-        return [[self.location[0],self.location[1]],[self.location[0],self.location[1]]]
-
 class Layer(MacroElement):
     """An abstract class for everything that is a Layer on the map.
     It will be used to define whether an object will be included in LayerControls.

folium/utilities.py

@@ -444,3 +444,21 @@ def none_max(x,y):
         return x
     else:
         return max(x,y)
+
+def iter_points(x):
+    """Iterates over a list representing a feature, and returns a list of points,
+    whatever the shape of the array (Point, MultiPolyline, etc).
+    """
+    if isinstance(x,list):
+        if len(x):
+            if isinstance(x[0],list):
+                out = []
+                for y in x:
+                    out += iter_points(y)
+                return out
+            else:
+                return [x]
+        else:
+            return []
+    else:
+        raise ValueError('List type expected {!r}'.format(x))