Add restriction such that at least a link or text parameter must …

…be passed to sharing methods

README.md

@@ -81,6 +81,7 @@ The options object lets you pre-populate the share view for the user. You can us
 | image     | Adds an image file from the xcode image assets.  image takes priority over imagelink. Only one out of two will load.  |
 | link      | Adds a URL to the message. The method automatically handles the URL shortening.  |
 
+**At least the `text` or `link` parameter must be specified**
 
 ### Callback
 The callback function runs when the native environment has information for the react environment

react-native-social-share.js

@@ -6,9 +6,17 @@ var KDSocialShare = require('react-native').NativeModules.KDSocialShare;
 
 module.exports = {
   shareOnTwitter: function(params, callback) {
-    return KDSocialShare.tweet(params, callback);
+    if (!(params['link'] || params['text'])) {
+      callback("missing_link_or_text");
+    } else {
+      return KDSocialShare.tweet(params, callback);
+    }
   },
   shareOnFacebook: function(params, callback) {
-    return KDSocialShare.shareOnFacebook(params, callback);
+    if (!(params['link'] || params['text'])) {
+      callback("missing_link_or_text");
+    } else {
+      return KDSocialShare.shareOnFacebook(params, callback);
+    }
   }
 };