Add event hook support

README.md

@@ -26,3 +26,48 @@ Here's a minimal example of the SDK usage:
 ## Building the SDK
 
 Clone this repo and run `npm install && npm run build`
+
+## Development
+
+To make development easier, run `npm install && npm run dev`. All file changes will automatically trigger a Webpack build.
+
+
+## Events
+
+The SDK provides the ability to listen to various events.
+
+### Available Events
+
+More events will be added over time. If you have a request, file an issue with your request!
+
+| Event Name         | Arguments       | Description                            |
+|--------------------|-----------------|----------------------------------------|
+| `instance.new`     | instanceDetails | Invoked when a new instance is created |
+
+
+### Events API
+
+#### `pwd.on(eventName, callback)`
+
+Add a listener to the provided event name. Returns the pwd object to allow chaining.
+
+**Example:**
+
+```
+pwd.on('instance.new', onNewInstance);
+
+function onNewInstance(instanceDetails) { 
+    console.log("New instance with name: " + instanceDetails.name);
+}
+```
+
+
+#### `pwd.off(eventName, callback)`
+
+Remove an event listener. Returns the pwd object to allow chaining.
+
+**Example:**
+
+```
+pwd.off('instance.new', onNewInstance);
+```

index.js

@@ -2,6 +2,7 @@ import Terminal from 'xterm'
 import fit from 'xterm/lib/addons/fit/fit.js'
 import * as io from 'socket.io-client'
 import 'xterm/dist/xterm.css'
+import * as Emitter from 'tiny-emitter';
 
 (function (window) {
 
@@ -97,6 +98,7 @@ import 'xterm/dist/xterm.css'
   var pwd = function () {
     this.instances = {};
     this.instanceBuffer = {};
+    this.eventEmitter = new Emitter();
     return;
   };
 
@@ -118,6 +120,7 @@ import 'xterm/dist/xterm.css'
     } else {
       console.warn('No terms specified, nothing to do.');
     }
+    return this;
   };
 
   // your sdk init function
@@ -158,7 +161,7 @@ import 'xterm/dist/xterm.css'
         var i = session.instances[name];
         // Setup empty terms
         i.terms = [];
-        self.instances[name] = i;
+        registerInstance(self, name, i);
       }
       !callback || callback();
     });
@@ -178,6 +181,29 @@ import 'xterm/dist/xterm.css'
     }
   };
 
+  /**
+   * Register a new event listener.
+   * @param eventName The event name to listen to
+   * @param callback A callback to be notified when the event is emitted
+   * @return the PWD object
+   */
+  pwd.prototype.on = function(eventName, callback) {
+    this.eventEmitter.on(eventName, callback);
+    return this;
+  };
+
+  /**
+   * Remove either a single event listener or all listeners for an event.
+   * If only the name is provided, all event listeners are removed.
+   * @param eventName The subject event name
+   * @param callback An optional callback to be removed.
+   * @return the PWD object
+   */
+  pwd.prototype.off = function(eventName, callback) {
+    this.eventEmitter.off(eventName, callback);
+    return this;
+  };
+
 
   // I know, opts and data can be ommited. I'm not a JS developer =(
   // Data needs to be sent encoded appropriately
@@ -202,14 +228,19 @@ import 'xterm/dist/xterm.css'
     }
   };
 
+  function registerInstance(pwd, name, instanceMetadata) {
+    pwd.instances[name] = instanceMetadata;
+    pwd.eventEmitter.emit("instance.new", instanceMetadata);
+  }
+
   pwd.prototype.createInstance = function(callback) {
     var self = this;
     //TODO handle http connection errors
     sendRequest('POST', self.opts.baseUrl + '/sessions/' + this.sessionId + '/instances', {headers:{'Content-type':'application/json'}}, {ImageName: self.opts.ImageName}, function(response) {
       if (response.status == 200) {
         var i = JSON.parse(response.responseText);
         i.terms = [];
-        self.instances[i.name] = i;
+        registerInstance(self, i.name, i);
         callback(undefined, i);
       } else if (response.status == 409) {
         var err = new Error();

package.json

@@ -4,7 +4,8 @@
   "description": "PWD sdk",
   "main": "sdk.js",
   "scripts": {
-    "build": "webpack -p"
+    "build": "webpack -p",
+    "dev": "webpack --watch"
   },
   "repository": {
     "type": "git",
@@ -24,6 +25,7 @@
   },
   "dependencies": {
     "socket.io-client": "^2.0.1",
+    "tiny-emitter": "^2.0.0",
     "xterm": "^2.6.0"
   }
 }