Promise the messages to the model

IPython/html/static/services/kernels/comm.js

@@ -1,193 +1,202 b''
 // Copyright (c) IPython Development Team.
 // Distributed under the terms of the Modified BSD License.
 
 define([
     'base/js/namespace',
     'jquery',
     'base/js/utils',
 ], function(IPython, $, utils) {
     "use strict";
 
     //-----------------------------------------------------------------------
     // CommManager class
     //-----------------------------------------------------------------------
     
     var CommManager = function (kernel) {
         this.comms = {};
         this.targets = {};
         if (kernel !== undefined) {
             this.init_kernel(kernel);
         }
     };
     
     CommManager.prototype.init_kernel = function (kernel) {
         // connect the kernel, and register message handlers
         this.kernel = kernel;
         var msg_types = ['comm_open', 'comm_msg', 'comm_close'];
         for (var i = 0; i < msg_types.length; i++) {
             var msg_type = msg_types[i];
             kernel.register_iopub_handler(msg_type, $.proxy(this[msg_type], this));
         }
     };
     
     CommManager.prototype.new_comm = function (target_name, data, callbacks, metadata) {
         // Create a new Comm, register it, and open its Kernel-side counterpart
         // Mimics the auto-registration in `Comm.__init__` in the IPython Comm
         var comm = new Comm(target_name);
         this.register_comm(comm);
         comm.open(data, callbacks, metadata);
         return comm;
     };
     
     CommManager.prototype.register_target = function (target_name, f) {
         // Register a target function for a given target name
         this.targets[target_name] = f;
     };
     
     CommManager.prototype.unregister_target = function (target_name, f) {
         // Unregister a target function for a given target name
         delete this.targets[target_name];
     };
     
     CommManager.prototype.register_comm = function (comm) {
         // Register a comm in the mapping
         this.comms[comm.comm_id] = comm;
         comm.kernel = this.kernel;
         return comm.comm_id;
     };
     
     CommManager.prototype.unregister_comm = function (comm) {
         // Remove a comm from the mapping
         delete this.comms[comm.comm_id];
     };
     
     // comm message handlers
     
     CommManager.prototype.comm_open = function (msg) {
         var content = msg.content;
         var that = this;
         
         return utils.load_class(content.target_name, content.target_module, 
             this.targets).then(function(target) {
 
             var comm = new Comm(content.target_name, content.comm_id);
             that.register_comm(comm);
             try {
                 target(comm, msg);
             } catch (e) {
                 comm.close();
                 that.unregister_comm(comm);
                 var wrapped_error = new utils.WrappedError("Exception opening new comm", e);
                 console.error(wrapped_error);
                 return Promise.reject(wrapped_error);
             }
             return comm;
         }, utils.reject('Could not open comm', true));
     };
     
     CommManager.prototype.comm_close = function (msg) {
         var content = msg.content;
         var comm = this.comms[content.comm_id];
         if (comm === undefined) {
             return;
         }
         this.unregister_comm(comm);
         try {
             comm.handle_close(msg);
         } catch (e) {
             console.log("Exception closing comm: ", e, e.stack, msg);
         }
     };
     
     CommManager.prototype.comm_msg = function (msg) {
         var content = msg.content;
         var comm = this.comms[content.comm_id];
         if (comm === undefined) {
             return;
         }
         try {
             comm.handle_msg(msg);
         } catch (e) {
             console.log("Exception handling comm msg: ", e, e.stack, msg);
         }
     };
     
     //-----------------------------------------------------------------------
     // Comm base class
     //-----------------------------------------------------------------------
     
     var Comm = function (target_name, comm_id) {
         this.target_name = target_name;
         this.comm_id = comm_id || utils.uuid();
         this._msg_callback = this._close_callback = null;
+
+        var that = this;
+        this.msg_promise = new Promise(function(resolve, reject) {
+            that.resolve_msg_promise = resolve;
+        });
     };
     
     // methods for sending messages
     Comm.prototype.open = function (data, callbacks, metadata) {
         var content = {
             comm_id : this.comm_id,
             target_name : this.target_name,
             data : data || {},
         };
         return this.kernel.send_shell_message("comm_open", content, callbacks, metadata);
     };
     
     Comm.prototype.send = function (data, callbacks, metadata, buffers) {
         var content = {
             comm_id : this.comm_id,
             data : data || {},
         };
         return this.kernel.send_shell_message("comm_msg", content, callbacks, metadata, buffers);
     };
     
     Comm.prototype.close = function (data, callbacks, metadata) {
         var content = {
             comm_id : this.comm_id,
             data : data || {},
         };
         return this.kernel.send_shell_message("comm_close", content, callbacks, metadata);
     };
     
     // methods for registering callbacks for incoming messages
     Comm.prototype._register_callback = function (key, callback) {
         this['_' + key + '_callback'] = callback;
     };
     
     Comm.prototype.on_msg = function (callback) {
         this._register_callback('msg', callback);
+        this.resolve_msg_promise();
     };
     
     Comm.prototype.on_close = function (callback) {
         this._register_callback('close', callback);
     };
     
     // methods for handling incoming messages
     
     Comm.prototype._maybe_callback = function (key, msg) {
         var callback = this['_' + key + '_callback'];
         if (callback) {
             try {
                 callback(msg);
             } catch (e) {
                 console.log("Exception in Comm callback", e, e.stack, msg);
             }
         }
     };
     
     Comm.prototype.handle_msg = function (msg) {
-        this._maybe_callback('msg', msg);
+        var that = this;
+        this.msg_promise.then(function() {
+            that._maybe_callback('msg', msg);
+        });
     };
     
     Comm.prototype.handle_close = function (msg) {
         this._maybe_callback('close', msg);
     };
     
     // For backwards compatability.
     IPython.CommManager = CommManager;
     IPython.Comm = Comm;
 
     return {
         'CommManager': CommManager,
         'Comm': Comm
     };
 });