Add SideBySide plugin

Author: Lo Conti Francesco

folium/plugins/side_by_side.py

@@ -0,0 +1,84 @@
+# -*- coding: utf-8 -*-
+
+from branca.element import CssLink, Figure, JavascriptLink
+
+from folium.map import Layer
+
+from jinja2 import Template
+
+
+class SideBySideLayers(Layer):
+    """
+    Creates a SideBySideLayers that takes two Layers and adds a sliding
+    control with the leaflet-side-by-side plugin.
+    Parameters
+    ----------
+    layer_left: Layer.
+        The left Layer within the side by side control.
+        Must  be created and added to the map before being passed to this class.
+    layer_right: Layer.
+        The left Layer within the side by side control.
+        Must  be created and added to the map before being passed to this class.
+    name : string, default None
+        The name of the Layer, as it will appear in LayerControls.
+    overlay : bool, default True
+        Adds the layer as an optional overlay (True) or the base layer (False).
+    control : bool, default True
+        Whether the Layer will be included in LayerControls.
+    show: bool, default True
+        Whether the layer will be shown on opening (only for overlays).
+    Examples
+    --------
+    >>> layer_left = WmsTileLayer(
+    ...          'http://this.wms.server/ncWMS/wms',
+    ...          name='Test WMS Data',
+    ...          styles='',
+    ...          fmt='image/png',
+    ...          transparent=True,
+    ...          layers='test_data',
+    ...          COLORSCALERANGE='0,10',
+    ...)
+    >>> layer_left.add_to(m)
+    >>> layer_right = WmsTileLayer(
+    ...          'http://this.wms.server/ncWMS/wms',
+    ...          name='Test WMS Data',
+    ...          styles='',
+    ...          fmt='image/png',
+    ...          transparent=True,
+    ...          layers='test_data_2',
+    ...          COLORSCALERANGE='0,5',
+    ...)
+    >>> layer_right.add_to(m)
+    >>> # Add layers to sidebyside control.
+    >>> sidebyside = SideBySideLayers(layer_left, layer_right)
+    >>> sidebyside.add_to(m)
+    See https://github.com/digidem/leaflet-side-by-side for more information.
+    """
+
+    _template = Template(u"""
+        {% macro script(this, kwargs) %}
+            var {{ this.get_name() }} = L.control.sideBySide(
+                {{ this.layer_left.get_name() }}, {{ this.layer_right.get_name() }}
+            ).addTo({{ this._parent.get_name() }});
+        {% endmacro %}
+        """)
+
+    def __init__(self, layer_left, layer_right, name=None, overlay=True, control=True, show=True):
+        super(SideBySideLayers, self).__init__(name=name,
+                                               overlay=overlay,
+                                               control=control,
+                                               show=show)
+        self._name = 'SideBySideLayers'
+        self.layer_left = layer_left
+        self.layer_right = layer_right
+
+    def render(self, **kwargs):
+        super(SideBySideLayers, self).render()
+
+        figure = self.get_root()
+        assert isinstance(figure, Figure), ('You cannot render this Element '
+                                            'if it is not in a Figure.')
+
+        figure.header.add_child(
+            JavascriptLink('http://lab.digital-democracy.org/leaflet-side-by-side/leaflet-side-by-side.js'),  # noqa
+            name='leaflet.sidebyside')