Added system that allows js to be required by widgets.

IPython/html/widgets/base.py

@@ -8,7 +8,7 b' import os'
 import IPython
 from IPython.kernel.comm import Comm
 from IPython.config import LoggingConfigurable
-from IPython.utils.traitlets import Unicode, Dict
+from IPython.utils.traitlets import Unicode, Dict, List
 from IPython.display import Javascript, display
 from IPython.utils.py3compat import string_types
 
@@ -18,6 +18,7 b' class Widget(LoggingConfigurable):'
     ### Public declarations
     target_name = Unicode('widget')
     default_view_name = Unicode()
+    js_requirements = List()
     
     
     ### Private/protected declarations
@@ -122,6 +123,10 b' class Widget(LoggingConfigurable):'
         if not view_name:
             view_name = self.default_view_name
         
+        # Require traitlet specified widget js
+        for requirement in self.js_requirements:
+            self._require_js(requirement)
+
         # Create a comm.
         if self.comm is None:
             self.comm = Comm(target_name=self.target_name)
@@ -154,4 +159,17 b' class Widget(LoggingConfigurable):'
                 pass # Eat errors, nom nom nom
         self.comm.send({"method": "update",
                         "state": state})
-    
  No newline at end of file
+    
+    ### Private methods
+
+    def _require_js(self, js_path):
+        # Since we are loading requirements that must be loaded before this call
+        # returns, preform async js load.
+        display(Javascript(data="""
+$.ajax({
+    url: '{0}',
+    async: false,
+    dataType: "script",
+    timeout: 1000, // Wait a maximum of one second for the script to load.
+});
+        """.format(js_path)))
  No newline at end of file

IPython/html/widgets/container.py

@@ -1,11 +1,12 b''
 import os
 
 from base import Widget
-from IPython.utils.traitlets import Unicode
+from IPython.utils.traitlets import Unicode, List
 from IPython.utils.javascript import display_all_js
 
 class ContainerWidget(Widget):
     target_name = Unicode('container_widget')
     default_view_name = Unicode('ContainerView')
+    js_requirements = List(["notebook/js/widgets/container.js"])
     
     _keys = []

IPython/html/widgets/float_range.py

@@ -1,12 +1,13 b''
 import os
 
 from base import Widget
-from IPython.utils.traitlets import Unicode, Float, Bool
+from IPython.utils.traitlets import Unicode, Float, Bool, List
 from IPython.utils.javascript import display_all_js
 
 class FloatRangeWidget(Widget):
     target_name = Unicode('FloatRangeWidgetModel')
     default_view_name = Unicode('FloatSliderView')
+    js_requirements = List(["notebook/js/widgets/float_range.js"])
     _keys = ['value', 'step', 'max', 'min', 'disabled', 'orientation']
     
     value = Float(0.0) 

IPython/html/widgets/int_range.py

@@ -1,12 +1,13 b''
 import os
 
 from base import Widget
-from IPython.utils.traitlets import Unicode, Int, Bool
+from IPython.utils.traitlets import Unicode, Int, Bool, List
 from IPython.utils.javascript import display_all_js
 
 class IntRangeWidget(Widget):
     target_name = Unicode('IntRangeWidgetModel')
     default_view_name = Unicode('IntSliderView')
+    js_requirements = List(["notebook/js/widgets/int_range.js"])
     _keys = ['value', 'step', 'max', 'min', 'disabled', 'orientation']
 
     value = Int(0) 

IPython/html/widgets/selection.py

@@ -7,6 +7,7 b' from IPython.utils.javascript import display_all_js'
 class SelectionWidget(Widget):
     target_name = Unicode('SelectionWidgetModel')
     default_view_name = Unicode('DropdownView')
+    js_requirements = List(["notebook/js/widgets/selection.js"])
     _keys = ['value', 'values', 'disabled']
 
     value = Unicode()

IPython/html/widgets/string.py

@@ -1,12 +1,13 b''
 import os
 
 from base import Widget
-from IPython.utils.traitlets import Unicode, Bool
+from IPython.utils.traitlets import Unicode, Bool, List
 from IPython.utils.javascript import display_all_js
 
 class StringWidget(Widget):
     target_name = Unicode('StringWidgetModel')
     default_view_name = Unicode('TextboxView')
+    js_requirements = List(["notebook/js/widgets/string.js"])
     _keys = ['value', 'row_count', 'disabled']
     
     value = Unicode()