Moved stream_remapping specification onto Callable

holoviews/core/spaces.py

@@ -402,6 +402,13 @@ class Callable(param.Parameterized):
     returned value based on the arguments to the function and the
     state of all streams on its inputs, to avoid calling the function
     unnecessarily.
+
+    A Callable may also specify a stream_mapping which allows
+    specifying which objects to attached linked streams to on
+    callbacks which return composite objects like (Nd)Layout and
+    GridSpace objects. The mapping should map between an integer index
+    or a type[.group][.label] specification and lists of streams
+    matching the object.
     """
 
     callable_function = param.Callable(default=lambda x: x, doc="""
@@ -410,11 +417,12 @@ class Callable(param.Parameterized):
     inputs = param.List(default=[], doc="""
          The list of inputs the callable function is wrapping.""")
 
-    def __init__(self, callable_function=None, **params):
+    def __init__(self, callable_function=None, stream_mapping={}, **params):
         if callable_function is not None:
             params['callable_function'] = callable_function
         super(Callable, self).__init__(**params)
         self._memoized = {}
+        self.stream_mapping = stream_mapping
 
     def __call__(self, *args, **kwargs):
         inputs = [i for i in self.inputs if isinstance(i, DynamicMap)]
@@ -796,7 +804,7 @@ def dynamic_redim(obj):
         return Dynamic(redimmed, shared_data=True, operation=dynamic_redim)
 
 
-    def collate(self, streams=[]):
+    def collate(self):
         """
         Collation allows collapsing DynamicMaps with invalid nesting
         hierarchies. This is particularly useful when defining
@@ -842,21 +850,48 @@ def collation_cb(*args, **kwargs):
             # Expand Layout/NdLayout
             from ..util import Dynamic
             new_item = self.last.clone(shared_data=False)
+
+            # Get stream mapping from callback
+            remapped_streams = []
+            streams = self.callback.stream_mapping
             for i, (k, v) in enumerate(self.last.items()):
-                if isinstance(streams, dict):
-                    vstreams = streams.get(i, [])
-                elif isinstance(streams, list):
-                    vstreams = streams[i] if i < len(streams) else []
+                vstreams = streams.get(i, [])
+                if not vstreams:
+                    if isinstance(self.last, Layout):
+                        for l in range(len(k)):
+                            path = '.'.join(k[:l])
+                            if path in streams:
+                                vstreams = streams[path]
+                                break
+                    else:
+                        vstreams = streams.get(k, [])
+                remapped_streams += vstreams
+
+                # Define collation callback
                 def collation_cb(*args, **kwargs):
                     return self[args][kwargs['collation_key']]
                 callback = Callable(partial(collation_cb, collation_key=k),
                                     inputs=[self])
                 vdmap = self.clone(callback=callback, shared_data=False,
                                    streams=vstreams)
+
+                # Remap source of streams
                 for stream in vstreams:
                     if stream.source is self:
                         stream.source = vdmap
                 new_item[k] = vdmap
+
+            unmapped_streams = [repr(stream) for stream in self.streams
+                                if (stream.source is self) and
+                                (stream not in remapped_streams)
+                                and stream.linked]
+            if unmapped_streams:
+                raise ValueError(
+                   'The following streams are set to be automatically '
+                   'linked to a plot, but no stream_mapping specifying '
+                   'which item in the (Nd)Layout to link it to was found:\n%s'
+                    % ', '.join(unmapped_streams)
+                )
             return new_item
         else:
             self.warning('DynamicMap does not need to be collated.')

holoviews/plotting/util.py

@@ -42,6 +42,8 @@ def collate(obj):
                                 "structure shown in the Composing Data tutorial"
                                 "(http://git.io/vtIQh)" % nested_type)
         return obj.collate()
+    if isinstance(obj, DynamicMap):
+        return obj.collate()
     if isinstance(obj, HoloMap):
         display_warning.warning("Nesting {0}s within a {1} makes it difficult "
                                 "to access your data or control how it appears; "

holoviews/streams.py

@@ -20,8 +20,9 @@ class Stream(param.Parameterized):
     the parameter dictionary when the trigger classmethod is called.
 
     Depending on the plotting backend certain streams may interactively
-    subscribe to events and changes by the plotting backend. To disable
-    this behavior instantiate the Stream with linked=False.
+    subscribe to events and changes by the plotting backend. For this
+    purpose use the LinkedStream baseclass, which enables the linked
+    option by default.
     """
 
     # Mapping from a source id to a list of streams
@@ -60,7 +61,7 @@ def trigger(cls, streams):
             stream.deactivate()
 
 
-    def __init__(self, rename={}, source=None, subscribers=[], linked=True, **params):
+    def __init__(self, rename={}, source=None, subscribers=[], linked=False, **params):
         """
         The rename argument allows multiple streams with similar event
         state to be used by remapping parameter names.
@@ -222,7 +223,18 @@ def __str__(self):
         return repr(self)
 
 
-class PositionX(Stream):
+class LinkedStream(Stream):
+    """
+    A LinkedStream indicates is automatically linked to plot interactions
+    on a backend via a Renderer. Not all backends may support dynamically
+    supplying stream data.
+    """
+
+    def __init__(self, linked=True, **params):
+        super(LinkedStream, self).__init__(linked=linked, **params)
+
+
+class PositionX(LinkedStream):
     """
     A position along the x-axis in data coordinates.
 
@@ -234,7 +246,7 @@ class PositionX(Stream):
            Position along the x-axis in data coordinates""", constant=True)
 
 
-class PositionY(Stream):
+class PositionY(LinkedStream):
     """
     A position along the y-axis in data coordinates.
 
@@ -246,7 +258,7 @@ class PositionY(Stream):
            Position along the y-axis in data coordinates""", constant=True)
 
 
-class PositionXY(Stream):
+class PositionXY(LinkedStream):
     """
     A position along the x- and y-axes in data coordinates.
 
@@ -287,7 +299,7 @@ class MouseLeave(PositionXY):
     """
 
 
-class PlotSize(Stream):
+class PlotSize(LinkedStream):
     """
     Returns the dimensions of a plot once it has been displayed.
     """
@@ -304,7 +316,7 @@ def transform(self):
                 'height': int(self.height * self.scale)}
 
 
-class RangeXY(Stream):
+class RangeXY(LinkedStream):
     """
     Axis ranges along x- and y-axis in data coordinates.
     """
@@ -316,7 +328,7 @@ class RangeXY(Stream):
       Range of the y-axis of a plot in data coordinates""")
 
 
-class RangeX(Stream):
+class RangeX(LinkedStream):
     """
     Axis range along x-axis in data coordinates.
     """
@@ -325,7 +337,7 @@ class RangeX(Stream):
       Range of the x-axis of a plot in data coordinates""")
 
 
-class RangeY(Stream):
+class RangeY(LinkedStream):
     """
     Axis range along y-axis in data coordinates.
     """
@@ -334,7 +346,7 @@ class RangeY(Stream):
       Range of the y-axis of a plot in data coordinates""")
 
 
-class Bounds(Stream):
+class Bounds(LinkedStream):
     """
     A stream representing the bounds of a box selection as an
     tuple of the left, bottom, right and top coordinates.
@@ -345,7 +357,7 @@ class Bounds(Stream):
         Bounds defined as (left, bottom, top, right) tuple.""")
 
 
-class Selection1D(Stream):
+class Selection1D(LinkedStream):
     """
     A stream representing a 1D selection of objects by their index.
     """