Call to undefined method stdClass::save() in yii framework - php

Question

I am building chats pop up where one user will initiate conversation with another user.
In my initiatechat function i have the following error Call to undefined method stdClass::save().
Look at codes and find THIS SAVE FUNCTION ==>> the save() function that throw error.
If two users have already initiated conversation this error does not happen.
public function actionInitiatechat() {
if (isset($_POST)){
//$message = Myclass::checkPostvalue($_POST['message']) ? $_POST['message'] : "";
$senderId = Myclass::checkPostvalue($_POST['sender']) ? $_POST['sender'] : "";
$receiverId = Myclass::checkPostvalue($_POST['receiver']) ? $_POST['receiver'] : "";
$messageType = Myclass::checkPostvalue($_POST['messageType']) ? $_POST['messageType'] : "";
$sourceId = Myclass::checkPostvalue($_POST['sourceId']) ? $_POST['sourceId'] : "";
$timeUpdate = time();
$message = $_POST['message'];
$Products = Products::model()->findByPk($sourceId);
if(isset($Products) && $Products->approvedStatus == 0)
{
echo "error";
}
else
{
$criteria = new CDbCriteria;
$criteria->condition = "(user1 = '$senderId' AND user2 = '$receiverId') OR (user1 = '$receiverId' AND user2 = '$senderId')";
$chatModel = Chats::model()->find($criteria);
$encodeMsg = urlencode($message);
if (empty($chatModel)){
$newChat = new Chats();
$newChat->user1 = $senderId;
$newChat->user2 = $receiverId;
$newChat->lastMessage = $encodeMsg;
$newChat->lastToRead = $receiverId;
$newChat->lastContacted = $timeUpdate;
$newChat->save();
$criteria = new CDbCriteria;
$criteria->condition = "(user1 = '$senderId' AND user2 = '$receiverId') OR (user1 = '$receiverId' AND user2 = '$senderId')";
$chatModel = Chats::model()->find($criteria);
}
$chatModel->lastContacted = $timeUpdate;
if ($chatModel->user1 == $senderId){
$chatModel->lastToRead = $chatModel->user2;
}else{
$chatModel->lastToRead = $chatModel->user1;
}
$chatModel->lastMessage = $encodeMsg;
THIS SAVE FUNCTION ==>> $chatModel->save();
$messageModel = new Messages();
$messageModel->message = $encodeMsg;
$messageModel->messageType = $messageType;
$messageModel->senderId = $senderId;
$messageModel->sourceId = $sourceId;
$messageModel->chatId = $chatModel->chatId;
$messageModel->createdDate = $timeUpdate;
$messageModel->save();
}
echo "success";
}
}
else
{
echo "failed";
}
}

Answer 1

The statement below is presumably returning a "bare" object of type stdClass, which doesn't define a save() method, hence your error.
$chatModel = Chats::model()->find($criteria);
Run var_dump($chatModel); immediately after this statement and see what type of object you're getting.