Merge pull request #15 from saravanaj/optional-callbacks

Make callbacks optional

Author: PowerKiKi

src/uploader.js

@@ -99,18 +99,24 @@ function uiUploader($log) {
             //console.info(event.loaded);
             file.loaded = event.loaded;
             file.humanSize = getHumanSize(event.loaded);
-            self.options.onProgress(file);
+            if (isFunction(self.options.onProgress)) {
+                self.options.onProgress(file);
+            }
         };
 
         // Triggered when upload is completed:
         xhr.onload = function() {
             self.activeUploads -= 1;
             self.uploadedFiles += 1;
             startUpload(self.options);
-            self.options.onCompleted(file, xhr.responseText, xhr.status);
+            if (isFunction(self.options.onCompleted)) {
+                self.options.onCompleted(file, xhr.responseText, xhr.status);
+            }            
             if (self.uploadedFiles === self.files.length) {
                 self.uploadedFiles = 0;
-                self.options.onCompletedAll(self.files);
+                if (isFunction(self.options.onCompletedAll)) {
+                    self.options.onCompletedAll(self.files);
+                }
             }
         };