Move _unpack_models to widget.js and widget serialization to widget.py

IPython/html/static/widgets/js/widget.js

@@ -10,6 +10,31 b' define(["widgets/js/manager",'
 ], function(widgetmanager, _, Backbone, $, utils, IPython){
     "use strict";
 
+    var unpack_models = function unpack_models(value, model) {
+        /**
+         * Replace model ids with models recursively.
+         */
+        var unpacked;
+        if ($.isArray(value)) {
+            unpacked = [];
+            _.each(value, function(sub_value, key) {
+                unpacked.push(unpack_models(sub_value, model));
+            });
+            return Promise.all(unpacked);
+        } else if (value instanceof Object) {
+            unpacked = {};
+            _.each(value, function(sub_value, key) {
+                unpacked[key] = unpack_models(sub_value, model);
+            });
+            return utils.resolve_promises_dict(unpacked);
+        } else if (typeof value === 'string' && value.slice(0,10) === "IPY_MODEL_") {
+            // get_model returns a promise already
+            return model.widget_manager.get_model(value.slice(10, value.length));
+        } else {
+            return Promise.resolve(value);
+        }
+    };
+
     var WidgetModel = Backbone.Model.extend({
         constructor: function (widget_manager, model_id, comm) {
             /**
@@ -767,6 +792,7 b' define(["widgets/js/manager",'
     });
 
     var widget = {
+        'unpack_models': unpack_models,
         'WidgetModel': WidgetModel,
         'WidgetView': WidgetView,
         'DOMWidgetView': DOMWidgetView,

IPython/html/static/widgets/js/widget_box.js

@@ -9,34 +9,10 b' define(['
     "bootstrap",
 ], function(widget, $, _, utils){
     "use strict";
-    var unpack_models = function unpack_models(value, model) {
-        /**
-         * Replace model ids with models recursively.
-         */
-        var unpacked;
-        if ($.isArray(value)) {
-            unpacked = [];
-            _.each(value, function(sub_value, key) {
-                unpacked.push(unpack_models(sub_value, model));
-            });
-            return Promise.all(unpacked);
-        } else if (value instanceof Object) {
-            unpacked = {};
-            _.each(value, function(sub_value, key) {
-                unpacked[key] = unpack_models(sub_value, model);
-            });
-            return utils.resolve_promises_dict(unpacked);
-        } else if (typeof value === 'string' && value.slice(0,10) === "IPY_MODEL_") {
-            // get_model returns a promise already
-            return model.widget_manager.get_model(value.slice(10, value.length));
-        } else {
-            return Promise.resolve(value);
-        }
-    };
 
     var BoxModel = widget.WidgetModel.extend({}, {
         serializers: _.extend({
-            children: {deserialize: unpack_models}
+            children: {deserialize: widget.unpack_models}
         }, widget.WidgetModel.serializers)
     });
 
@@ -179,7 +155,6 b' define(['
     });
 
     return {
-        'unpack_models': unpack_models,
         'BoxModel': BoxModel,
         'BoxView': BoxView,
         'FlexBoxView': FlexBoxView,

IPython/html/widgets/__init__.py

@@ -1,4 +1,4 b''
-from .widget import Widget, DOMWidget, CallbackDispatcher, register
+from .widget import Widget, DOMWidget, CallbackDispatcher, register, widget_serialization
 
 from .trait_types import Color
 

IPython/html/widgets/widget.py

@@ -24,6 +24,33 b' from IPython.utils.traitlets import Unicode, Dict, Instance, Bool, List, \\'
 from IPython.utils.py3compat import string_types
 from .trait_types import Color
 
+
+def _widget_to_json(x):
+    if isinstance(x, dict):
+        return {k: _widget_to_json(v) for k, v in x.items()}
+    elif isinstance(x, (list, tuple)):
+        return [_widget_to_json(v) for v in x]
+    elif isinstance(x, Widget):
+        return "IPY_MODEL_" + x.model_id
+    else:
+        return x
+
+def _json_to_widget(x):
+    if isinstance(x, dict):
+        return {k: _json_to_widget(v) for k, v in x.items()}
+    elif isinstance(x, (list, tuple)):
+        return [_json_to_widget(v) for v in x]
+    elif isinstance(x, string_types) and x.startswith('IPY_MODEL_') and x[10:] in Widget.widgets:
+        return Widget.widgets[x[10:]]
+    else:
+        return x
+
+widget_serialization = {
+    'from_json': _json_to_widget,
+    'to_json': _widget_to_json
+}
+
+
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------

IPython/html/widgets/widget_box.py

@@ -6,35 +6,10 b' Represents a container that can be used to group other widgets.'
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
-from .widget import DOMWidget, Widget, register
+from .widget import DOMWidget, Widget, register, widget_serialization
 from IPython.utils.traitlets import Unicode, Tuple, TraitError, Int, CaselessStrEnum
 from .deprecated import DeprecatedClass
 
-def _widget_to_json(x):
-    if isinstance(x, dict):
-        return {k: _widget_to_json(v) for k, v in x.items()}
-    elif isinstance(x, (list, tuple)):
-        return [_widget_to_json(v) for v in x]
-    elif isinstance(x, Widget):
-        return "IPY_MODEL_" + x.model_id
-    else:
-        return x
-
-def _json_to_widget(x):
-    if isinstance(x, dict):
-        return {k: _json_to_widget(v) for k, v in x.items()}
-    elif isinstance(x, (list, tuple)):
-        return [_json_to_widget(v) for v in x]
-    elif isinstance(x, string_types) and x.startswith('IPY_MODEL_') and x[10:] in Widget.widgets:
-        return Widget.widgets[x[10:]]
-    else:
-        return x
-
-widget_serialization = {
-    'from_json': _json_to_widget,
-    'to_json': _widget_to_json
-}
-
 
 @register('IPython.Box')
 class Box(DOMWidget):