Address @jasongrout 's review comments, take 2

IPython/html/static/widgets/js/manager.js

@@ -88,38 +88,32 b' define(['
         /**
          * Displays a view for a particular model.
          */
-        var that = this;
-        return new Promise(function(resolve, reject) {
-            var cell = that.get_msg_cell(msg.parent_header.msg_id);
+        var cell = this.get_msg_cell(msg.parent_header.msg_id);
             if (cell === null) {
-                reject(new Error("Could not determine where the display" + 
+            return Promise.reject(new Error("Could not determine where the display" + 
                     " message was from.  Widget will not be displayed"));
             } else {
-                return that.display_view_in_cell(cell, model)
-                .catch(function(error) { 
-                    reject(new utils.WrappedError('View could not be displayed.', error)); 
-                });
+            return this.display_view_in_cell(cell, model)
+                .catch(utils.reject('View could not be displayed.', true)); 
             }
-        });
     };
 
     WidgetManager.prototype.display_view_in_cell = function(cell, model) {
         // Displays a view in a cell.
-        var that = this;
-        return new Promise(function(resolve, reject) {
             if (cell.display_widget_view) {
-                cell.display_widget_view(that.create_view(model, {cell: cell}))
-                .then(function(view) {
+            var that = this;
+            return cell.display_widget_view(this.create_view(model, {
+                cell: cell,
+                // Only set cell_index when view is displayed as directly.
+                cell_index: that.notebook.find_cell_index(cell),
+            })).then(function(view) {
                     that._handle_display_view(view);
                     view.trigger('displayed');
                     resolve(view);
-                }, function(error) { 
-                    reject(new utils.WrappedError('Could not create or display view', error)); 
-                });
+            }).catch(utils.reject('Could not create or display view', true)); 
             } else {
-                reject(new Error('Cell does not have a `display_widget_view` method'));
+            return Promise.reject(new Error('Cell does not have a `display_widget_view` method'));
             }
-        });
     };
 
     WidgetManager.prototype._handle_display_view = function (view) {
@@ -315,7 +309,7 b' define(['
         //  Dictionary of options with the following contents:
         //      only_displayed: (optional) boolean=false
         //          Only return models with one or more displayed views.
-        //      not_alive: (optional) boolean=false
+        //      not_live: (optional) boolean=false
         //          Include models that have comms with severed connections.
         //
         // Returns
@@ -331,8 +325,8 b' define(['
                     // If the model has one or more views defined for it,
                     // consider it displayed.
                     var displayed_flag = !(options && options.only_displayed) || Object.keys(model.views).length > 0;
-                    var alive_flag = (options && options.not_alive) || model.comm_alive;
-                    if (displayed_flag && alive_flag) {
+                    var live_flag = (options && options.not_live) || model.comm_live;
+                    if (displayed_flag && live_flag) {
                         state[model_id] = {
                             model_name: model.name,
                             model_module: model.module,
@@ -344,13 +338,8 b' define(['
                         for (var id in model.views) {
                             if (model.views.hasOwnProperty(id)) {
                                 var view = model.views[id];
-                                var cell = view.options.cell;
-
-                                // Only store the cell reference if this view is a top level
-                                // child of the cell.
-                                if (cell.widget_views.indexOf(view) != -1) {
-                                    var cell_index = that.notebook.find_cell_index(cell);
-                                    state[model_id].views.push(cell_index);
+                                if (view.options.cell_index) {
+                                    state[model_id].views.push(view.options.cell_index);
                                 }
                             }
                         }
@@ -358,7 +347,7 b' define(['
                 }
             }
             return state;
-        });
+        }).catch(utils.reject('Could not get state of widget manager', true));
     };
     
     WidgetManager.prototype.set_state = function(state) {
@@ -383,7 +372,7 b' define(['
                 kernel.comm_manager.register_comm(new_comm);
 
                 // Create the model using the recreated comm.  When the model is
-                // created we don't know yet if the comm is valid so set_comm_alive
+                // created we don't know yet if the comm is valid so set_comm_live
                 // false.  Once we receive the first state push from the back-end
                 // we know the comm is alive.
                 var views = kernel.widget_manager.create_model({
@@ -392,12 +381,12 b' define(['
                     model_module: state[model_id].model_module})
                 .then(function(model) {
 
-                    model.set_comm_alive(false);
+                    model.set_comm_live(false);
                     var view_promise = Promise.resolve().then(function() {
                         return model.set_state(state[model.id].state);
                     }).then(function() {
                         model.request_state().then(function() {
-                            model.set_comm_alive(true);
+                            model.set_comm_live(true);
                         });
 
                         // Display the views of the model.

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

@@ -31,6 +31,7 b' define(["widgets/js/manager",'
             this.state_lock = null;
             this.id = model_id;
             this.views = {};
+            this._resolve_received_state = {};
 
             if (comm !== undefined) {
                 // Remember comm associated with the model.
@@ -42,9 +43,9 b' define(["widgets/js/manager",'
                 comm.on_msg($.proxy(this._handle_comm_msg, this));
 
                 // Assume the comm is alive.
-                this.set_comm_alive(true);
+                this.set_comm_live(true);
             } else {
-                this.set_comm_alive(false);
+                this.set_comm_live(false);
             }
             return Backbone.Model.apply(this);
         },
@@ -69,24 +70,24 b' define(["widgets/js/manager",'
                 return;
             }
 
+            var msg_id = this.comm.send({method: 'request_state'}, callbacks || this.widget_manager.callbacks());
+
             // Promise that is resolved when a state is received
             // from the back-end.
             var that = this;
             var received_state = new Promise(function(resolve) {
-                that._resolve_received_state = resolve;
+                that._resolve_received_state[msg_id] = resolve;
             });
-
-            this.comm.send({method: 'request_state'}, callbacks || this.widget_manager.callbacks());
             return received_state;
         },
 
-        set_comm_alive: function(alive) {
+        set_comm_live: function(live) {
             /** 
-             * Change the comm_alive state of the model.
+             * Change the comm_live state of the model.
              */
-            if (this.comm_alive === undefined || this.comm_alive != alive) {
-                this.comm_alive = alive;
-                this.trigger(alive ? 'comm_is_live' : 'comm_is_dead', {model: this});
+            if (this.comm_live === undefined || this.comm_live != live) {
+                this.comm_live = live;
+                this.trigger(live ? 'comm:live' : 'comm:dead', {model: this});
             }
         },
 
@@ -126,9 +127,17 b' define(["widgets/js/manager",'
             var that = this;
             switch (method) {
                 case 'update':
-                    this.state_change = this.state_change.then(function() {
+                    this.state_change = this.state_change
+                        .then(function() {
                         return that.set_state(msg.content.data.state);
-                    }).catch(utils.reject("Couldn't process update msg for model id '" + String(that.id) + "'", true));
+                        }).catch(utils.reject("Couldn't process update msg for model id '" + String(that.id) + "'", true))
+                        .then(function() {
+                            var parent_id = msg.parent_header.msg_id;
+                            if (that._resolve_received_state[parent_id] !== undefined) {
+                                that._resolve_received_state[parent_id].call();
+                                delete that._resolve_received_state[parent_id];
+                            }
+                        }).catch(utils.reject("Couldn't resolve state request promise.", true));
                     break;
                 case 'custom':
                     this.trigger('msg:custom', msg.content.data.content);
@@ -150,11 +159,6 b' define(["widgets/js/manager",'
                 } finally {
                     that.state_lock = null;
                 }
-                
-                if (that._resolve_received_state !== undefined) {
-                    that._resolve_received_state();
-                }
-                return Promise.resolve();
             }, utils.reject("Couldn't set model state", true));
         },