Emoji to JSON encoded, post to web server

Question

Please help me with my problem in posting a JSON decoded emoji character. I have a UITextView, this text view may have a emoji character. I am posting the data to a web server with the UITextView.text presented as JSON, the problem is when the text has a an emoji, I am not able to get the data. What I do is:

$postData = file_get_contents("php://input") to get the data.

then I use

$post = json_decode($postData,true);

to decode the data and have a assoc array and insert the data in database.

here is a code snippet when I insert my data into database.

$postData = file_get_contents("php://input");
//$postData = '{"body":"characters here ","subject":"subject here","username":"janus","from_id":"185","to_id":"62"}';
    $post = json_decode($postData,true);
        $data=array(
                'user_id_from'=>mysql_real_escape_string($post['from_id']),
                'user_id_to'=>mysql_real_escape_string($post['to_id']),
                'subject'=>mysql_real_escape_string($post['subject']),
                'message'=>mysql_real_escape_string($post['body']));

                $messages_obj->insert($data);

Without an emoji character found, it works fine. no problem. the problem is when an emoji character found, the data in $post (decoded data) is null.

I tried to use dummy data (line 2 in code snippet)

//$postData = '{"body":"characters here ","subject":"subject here","username":"janus","from_id":"185","to_id":"62"}';

and I succesfully inserted the emoji characters in database. I dont know why but It dont work the same when the data is from the device ($postData = file_get_contents("php://input"))

This is how I encode and post my data in client.

    NSMutableDictionary *messageDetails = [[NSMutableDictionary alloc] init];
[messageDetails setObject:[loginItems objectForKey:@"user_id"] forKey:@"from_id"];
[messageDetails setObject:recipientID forKey:@"to_id"];
[messageDetails setObject:@"subject here" forKey:@"subject"];
[messageDetails setObject:newMessageField.text forKey:@"body"];
    [messageDetails setObject:[loginItems objectForKey:@"username"] forKey:@"username"];


NSString *strPostData = [messageDetails JSONRepresentation];
[messageDetails release];

NSData *postData = [NSData dataWithBytes:[strPostData   UTF8String] length:[strPostData  length]];
[urlRequest setHTTPMethod:@"POST"];
[urlRequest setHTTPBody:postData];

BTW, who made these emoji characters? He is ruining my life!

Answer 1

Once the data is sent to your php script you need to convert it to a multibyte string:

$content = mb_convert_encoding($content, 'UTF-8');

You can use this function:

function cb($content){

  if(!mb_check_encoding($content, 'UTF-8')
   OR !($content === mb_convert_encoding(mb_convert_encoding($content, 'UTF-32', 'UTF-8' ), 'UTF-8', 'UTF-32'))) {

    $content = mb_convert_encoding($content, 'UTF-8');

  }
  return $content;
}

Edit: The data was probably of type application/x-www-form-urlencoded for us and that function converted it correctly.

Answer 2

emoji characters are most likely transcoded in UNICODE, so it should be sufficient to just send, receive and manage your data in UTF-8.

When receiving with this

$postData = file_get_contents("php://input") 

(I suppose that is a real URL), make sure your php script sends an Content-Encoding header (like the following, choose a MIME-type that suits you)

 header("Content-Type: text/html; charset=utf-8");

Answer 3

Please follow following steps:

• Convert Emoji characters to base64 and send to server.
• On server side save base64 in database without decode.
• When you want to display Emoji on Application then retrieve same base64 data from server.
• Decode retrieve string and display on app.
• Your Emoji character will display properly.