COMM: mirror Python callback API in Javascript

IPython/html/static/notebook/js/comm.js

@@ -1,150 +1,173
 //----------------------------------------------------------------------------
 //  Copyright (C) 2013  The IPython Development Team
 //
 //  Distributed under the terms of the BSD License.  The full license is in
 //  the file COPYING, distributed as part of this software.
 //----------------------------------------------------------------------------
 
 //============================================================================
 // Comm and CommManager bases
 //============================================================================
 /**
  * Base Comm classes
  * @module IPython
  * @namespace IPython
  * @submodule comm
  */
 
 var IPython = (function (IPython) {
     "use strict";
 
     //-----------------------------------------------------------------------
     // CommManager class
     //-----------------------------------------------------------------------
     
     var CommManager = function (kernel) {
         this.comms = {};
         this.targets = {comm : Comm};
         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.register_target = function (target, constructor) {
         // Register a constructor for a given target key
         this.targets[target] = constructor;
     };
     
     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_id) {
         // Remove a comm from the mapping
         delete this.comms[comm_id];
     };
     
     // comm message handlers
     
     CommManager.prototype.comm_open = function (msg) {
         var content = msg.content;
         var callback = this.targets[content.target];
         if (callback === undefined) {
             console.log("No such target registered: ", content.target);
             console.log("Available targets are: ", this.targets);
             return;
         }
         var comm = new Comm(content.comm_id);
         this.register_comm(comm);
         callback(comm);
         comm.handle_open(msg);
     };
     
     CommManager.prototype.comm_close = function (msg) {
         var content = msg.content;
         var comm = this.comms[content.comm_id];
         if (comm === undefined) {
             return;
         }
         delete this.comms[content.comm_id];
         comm.handle_close(msg);
     };
     
     CommManager.prototype.comm_msg = function (msg) {
         var content = msg.content;
         var comm = this.comms[content.comm_id];
         if (comm === undefined) {
             return;
         }
         comm.handle_msg(msg);
     };
     
     //-----------------------------------------------------------------------
     // Comm base class
     //-----------------------------------------------------------------------
     
     var Comm = function (comm_id, target) {
         this.comm_id = comm_id;
         this.target = target || 'comm';
+        this._msg_callback = this._open_callback = this._close_callback = null;
     };
     
     // methods for sending messages
     Comm.prototype.open = function (data) {
         var content = {
             comm_id : this.comm_id,
             target : this.target,
             data : data || {},
         };
         this.kernel.send_shell_message("comm_open", content);
     };
     
     Comm.prototype.send = function (data) {
         var content = {
             comm_id : this.comm_id,
             data : data || {},
         };
         return this.kernel.send_shell_message("comm_msg", content);
     };
     
     Comm.prototype.close = function (data) {
         var content = {
             comm_id : this.comm_id,
             data : data || {},
         };
         return this.kernel.send_shell_message("comm_close", content);
     };
     
+    // methods for registering callbacks for incoming messages
+    Comm.prototype._register_callback = function (key, callback) {
+        this['_' + key + '_callback'] = callback;
+    };
+    
+    Comm.prototype.on_open = function (callback) {
+        this._register_callback('open', callback);
+    };
+    
+    Comm.prototype.on_msg = function (callback) {
+        this._register_callback('msg', callback);
+    };
+    
+    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) callback(msg);
+    };
+    
     Comm.prototype.handle_open = function (msg) {
-        $([this]).trigger("comm_open", msg);
+        this._maybe_callback('open', msg);
     };
     
     Comm.prototype.handle_msg = function (msg) {
-        $([this]).trigger("comm_msg", msg);
+        this._maybe_callback('msg', msg);
     };
     
     Comm.prototype.handle_close = function (msg) {
-        $([this]).trigger("comm_close", msg);
+        this._maybe_callback('close', msg);
     };
     
     IPython.CommManager = CommManager;
     IPython.Comm = Comm;
 
     return IPython;
 
 }(IPython));