Fix as_leaflet_layer

docs/source/layers/layer_like.rst

@@ -14,12 +14,16 @@ Downstream objects should implement an ``as_leaflet_layer`` method that returns
 an ``ipyleaflet`` type capable of being added to the ``Map``.
 
 Here is a simple example of creating a custom data class to hold heatmap data
-(coordinates with some numerical value).
+(coordinates with some numerical value). We can use that custom data class and
+because it has an ``as_leaflet_layer`` interface, we can pass the object
+directly to :func:`ipyleaflet.Map.add`.
+
 
 
 .. jupyter-execute::
 
   import numpy as np
+  from ipyleaflet import Map
 
 
   class MyHeatMap:
@@ -39,15 +43,6 @@ Here is a simple example of creating a custom data class to hold heatmap data
               radius=self.radius,
           )
 
-We can now use that custom data class and because it has an
-``as_leaflet_layer`` interface, we can pass the object directly to
-:func:`ipyleaflet.Map.add`.
-
-
-.. jupyter-execute::
-
-  from ipyleaflet import Map
-
   n = 1000
   data = MyHeatMap(
       np.random.uniform(-80, 80, (n, 2)),

ipyleaflet/leaflet.py

@@ -1172,8 +1172,6 @@ def add(self, layer):
 
         if isinstance(layer, dict):
             layer = basemap_to_tiles(layer)
-        elif hasattr(layer, 'as_leaflet_layer'):
-            layer = layer.as_leaflet_layer()
         if layer.model_id in self._layer_ids:
             raise LayerException('layer already in layergroup: %r' % layer)
         self.layers = tuple([layer for layer in self.layers] + [layer])
@@ -2525,6 +2523,9 @@ def add(self, item):
         item: Layer or Control instance
             The layer or control to add.
         """
+        if hasattr(item, 'as_leaflet_layer'):
+            item = item.as_leaflet_layer()
+
         if isinstance(item, Layer):
             if isinstance(item, dict):
                 item = basemap_to_tiles(item)