Added annyang.removeCallback() command (#112)

Removes event callbacks

- Pass an event name and a callback command to remove that callback
command from that event type.
- Pass just an event name to remove all callback commands from that
event type.
- Pass undefined as event name and a callback command to remove that
callback command from all event types.
- Pass no params to remove all callback commands from all event types.

#### Examples:
````javascript
annyang.addCallback('start', myFunction1);
annyang.addCallback('start', myFunction2);
annyang.addCallback('end', myFunction1);
annyang.addCallback('end', myFunction2);

// Remove myFunction2 from being called on start:
annyang.removeCallback('start', myFunction2);

// Remove all callbacks attached to end event:
annyang.removeCallback('end');

// Remove all callbacks from all events:
annyang.removeCallback();
````

annyang.js

@@ -466,6 +466,57 @@
  callbacks[type].push({callback: cb, context: context || this});
  },
 
+ /**
+ * Remove callbacks from events.
+ *
+ * - Pass an event name and a callback command to remove that callback command from that event type.
+ * - Pass just an event name to remove all callback commands from that event type.
+ * - Pass undefined as event name and a callback command to remove that callback command from all event types.
+ * - Pass no params to remove all callback commands from all event types.
+ *
+ * #### Examples:
+ * ````javascript
+ * annyang.addCallback('start', myFunction1);
+ * annyang.addCallback('start', myFunction2);
+ * annyang.addCallback('end', myFunction1);
+ * annyang.addCallback('end', myFunction2);
+ *
+ * // Remove myFunction2 from being called on start:
+ * annyang.removeCallback('start', myFunction2);
+ *
+ * // Remove all callbacks attached to end event:
+ * annyang.removeCallback('end');
+ *
+ * // Remove all callbacks from all events:
+ * annyang.removeCallback();
+ * ````
+ *
+ * @param type Name of event type to remove callback from
+ * @param callback The callback function to remove
+ * @returns undefined
+ * @method removeCallback
+ */
+ removeCallback: function(type, callback) {
+ var compareWithCallbackParameter = function(cb) {
+ return cb.callback !== callback;
+ };
+ // Go over each callback type in callbacks store object
+ for (var callbackType in callbacks) {
+ if (callbacks.hasOwnProperty(callbackType)) {
+ // if this is the type user asked to delete, or he asked to delete all, go ahead.
+ if (type === undefined || type === callbackType) {
+ // If user asked to delete all callbacks in this type or all types
+ if (callback === undefined) {
+ callbacks[callbackType] = [];
+ } else {
+ // Remove all matching callbacks
+ callbacks[callbackType] = callbacks[callbackType].filter(compareWithCallbackParameter);
+ }
+ }
+ }
+ }
+ },
+
  /**
  * Returns true if speech recognition is currently on.
  * Returns false if speech recognition is off or annyang is paused.

docs/README.md

@@ -182,6 +182,41 @@ annyang.addCallback('errorNetwork', notConnected, this);
 * **Function** *callback* - The function to call when event is triggered
 * **Object** *[context]* - Optional context for the callback function
 
+## removeCallback(type, callback)
+
+Remove callbacks from events.
+
+- Pass an event name and a callback command to remove that callback command from that event type.
+- Pass just an event name to remove all callback commands from that event type.
+- Pass undefined as event name and a callback command to remove that callback command from all event types.
+- Pass no params to remove all callback commands from all event types.
+
+#### Examples:
+````javascript
+annyang.addCallback('start', myFunction1);
+annyang.addCallback('start', myFunction2);
+annyang.addCallback('end', myFunction1);
+annyang.addCallback('end', myFunction2);
+
+// Remove myFunction2 from being called on start:
+annyang.removeCallback('start', myFunction2);
+
+// Remove all callbacks attached to end event:
+annyang.removeCallback('end');
+
+// Remove all callbacks from all events:
+annyang.removeCallback();
+````
+
+### Params:
+
+* *type* Name of event type to remove callback from
+* *callback* The callback function to remove
+
+### Return:
+
+* undefined
+
 ## isListening()
 
 Returns true if speech recognition is currently on.