Adds a function to lookup a member's id within a group

README.md

@@ -64,6 +64,7 @@ public function getGroupMessagesAfter($group_id, $message_id, $limit=20)
 public function getGroupMessagesSince($group_id, $message_id, $limit=20)
 public function getGroupNameById($id)
 public function getGroupIdByName($name)
+public function getGroupMemberId($group_id, $name, $caseSensitive = FALSE)
 public function isMemberOfGroup($grp)
 public function sendGroupMessage($group_id, $text, array $attachments=array(), $source_guid=null)
 ```

src/Client.php

@@ -791,6 +791,28 @@ public function disableSmsMode() {
 
     // ADDITIONAL METHODS
 
+    /**
+     * Looks up a member's id within a group
+     * 
+     * @param int    $group_id      Group id
+     * @param string $name          Member name
+     * @param bool   $caseSensitive Name is case sensitive (default NO)
+     * 
+     * @return mixed   Member id or FALSE if not found
+     */
+    public function getGroupMemberId($group_id, $name, $caseSensitive = FALSE) {
+        $group_members = $this->getGroupMembers($group_id);
+
+        $name = (!$caseSensitive) ? strtolower($name) : $name;
+
+        foreach ($group_members as $member) {
+            $member_name = (!$caseSensitive) ? strtolower($member['nickname']) : $member['nickname'];
+            if ($member_name == $name) return $member['user_id'];
+        }
+
+        return FALSE;
+    }
+
     /**
      * Looks up member ids and member name positions
      * in the message string and returns a mentions