title: How to tag friends in startWithGraphPath Facebook iOS
body: <p>I can't seem to get my posts to work using the Facebook SDK for iOS. I am using the "startWithGraphPath:parameters:HTTPMethod:completionHandler:" function. I can get the message, place, and picture working but I can't seem to tag friends. I have tried setting the NSDictionary key and object to </p>
  
  <pre><code>parameters[@"tags"] = self.friendsIDs; 
  </code></pre>
  
  <p>which is a string of comma separated Facebook User ID's (per the Facebook reference page: <a href="https://developers.facebook.com/docs/reference/api/user/#posts" rel="nofollow">https://developers.facebook.com/docs/reference/api/user/#posts</a>). However this always comes up:</p>
  
  <pre><code>com.facebook.sdk:ParsedJSONResponseKey={
      body =     {
          error =         {
              code = 100;
              message = "(#100) param tags must be an array.";
              type = OAuthException;
  </code></pre>
  
  <p>So then I put them in an array and it still didn't work. In fact  then I get a different error: </p>
  
  <p><code>-[__NSArrayM length]: unrecognized selector sent to instance 0x1228abc0
  2013-09-26 16:47:36.917 DrinkingGamePicker[27558:a0b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSArrayM length]: unrecognized selector sent to instance 0x1228abc0</code>sent to instance 0x1228abc0'  </p>
  
  <p>Anyone know how to format these parameters? I can't find any documentation or clear examples. Thanks in advance.</p>
  
  <p>As a side note, does anyone know how to post from an app and tag people but not a place? I feel like every method means you have to at least tag a place first.</p>
  
  <p>Thanks! </p>