Promisify all the things!

README.md

@@ -2,7 +2,6 @@ instagram-node
 ==============
 
 NodeJS driver for the Instagram API.
-In production at http://totems.co aggregating more than 200 data points per seconds
 
 ## Installation
 
@@ -58,7 +57,7 @@ second method, ```authorize_user```, can be used to retrieve and set an access t
 for a user, allowing your app to act fully on his/her behalf. This method takes
 three parameters: a ```response_code``` which is sent as a GET parameter once a
 user has authorized your app and instagram has redirected them back to your
-authorization redirect URI, a ```redirect_uri``` which is the same one 
+authorization redirect URI, a ```redirect_uri``` which is the same one
 supplied to ```get_authorization_url```, and a callback that takes
 two parameters ```err``` and ```result```. ```err``` will be populated if and
 only if the request to authenticate the user has failed for some reason.
@@ -252,6 +251,28 @@ or just one with this:
 ig.del_subscription({ id: 1 }, function(err, subscriptions, remaining, limit){});
 ```
 
+## Promises
+
+All methods can be used as promises instead of using callbacks, if `.promisify()` is called (this changes all methods signatures and they no longer require a callback to be passed.) Example:
+
+```javascript
+api.use({
+  client_id: YOUR_CLIENT_ID,
+  client_secret: YOUR_CLIENT_SECRET
+});
+
+api.promisify();
+
+app.get('/', function (req, res) {
+    // BEFORE:
+    // api.user_media_recent('30739527', function (err, result) {
+    //     res.send(JSON.stringify(result));
+    // });
+
+    // AFTER:
+    api.user_media_recent('30739527').then(JSON.stringify).then(res.send.bind(res));
+});
+```
 
 
 ## Errors

lib/instagram.js

@@ -102,7 +102,36 @@ var instagram = function(spec, my) {
   var sign_request;                     /* sign_request(endpoint, params, client_secret);   */
   var sort_object;                      /* sort_object(params);                             */
 
-  var that = {};
+  var that = {
+    promisify: function () {
+      var api = this;
+
+      Object.keys(api).forEach(function (key) {
+        if (key === 'promisify' || key === 'get_authorization_url' || key === 'use') {
+          return false;
+        }
+
+        var oldFn = api[key];
+        api[key] = function () {
+          var context = this,
+              args = Array.prototype.slice.call(arguments);
+
+          return new Promise(function (fulfill, reject) {
+            args.push(function (err) {
+              if (err) {
+                reject(err);
+              } else {
+                Array.prototype.shift.call(arguments);
+                fulfill.apply(null, arguments);
+              }
+            });
+
+            oldFn.apply(null, args);
+          });
+        };
+      });
+    }
+  };
 
   /*******************************/
   /*       Private helpers       */