In this post I will be discussing on how to send messages to other users and members of groups in PHP.

Implementation

We need to create a table for Message where we can store sender’s id and receiver id, text which are required while sending and receiving messages.

MYSQL Syntax of Messages Table

DROP TABLE IF EXISTS `Messages`;
CREATE TABLE IF NOT EXISTS `Messages` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `Datum` int(11) NOT NULL,
  `SUID` int(11) NOT NULL DEFAULT '0',
  `RUID` int(11) NOT NULL DEFAULT '0',
  `isRead` char(1) NOT NULL DEFAULT 'N',
  `Text` text NOT NULL,
  PRIMARY KEY (`id`),
  KEY `Datum` (`Datum`),
  KEY `SUID` (`SUID`),
  KEY `RUID` (`RUID`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='Fuers interen Communikationssystem' AUTO_INCREMENT=1 ;

After initializing the table. we need to create a Page for sending and receiving messages which looks like this

      $messages_table_entry = array(
      'new' => $message['isRead'] == 'N' ? '<span class="glyphicon  glyphicon-envelope"></span>' : '',
          'timestamp' => date("Y-m-d H:i", $message['Datum']),
          'from' => User_Nick_render($sender_user_source),
          'to' => User_Nick_render($receiver_user_source),
          'text' => str_replace("\n", '<br />', $message['Text']) 
      );

The message table looks something like this.

we need to store the sender and receiver id and update the message table .The function for sending messages looks something like this.

function Message_send($id, $text) {
  global $user;
  $text = preg_replace("/([^\p{L}\p{P}\p{Z}\p{N}\n]{1,})/ui", '', strip_tags($text));
  $to = preg_replace("/([^0-9]{1,})/ui", '', strip_tags($id));

  if (($text != "" && is_numeric($to)) && (sql_num_query("SELECT * FROM `User` WHERE `UID`='" . sql_escape($to) . "' AND NOT `UID`='" . sql_escape($user['UID']) . "' LIMIT 1") > 0)) {
    sql_query("INSERT INTO `Messages` SET `Datum`='" . sql_escape(time()) . "', `SUID`='" . sql_escape($user['UID']) . "', `RUID`='" . sql_escape($to) . "', `Text`='" . sql_escape($text) . "'");
    return true;
  } else {
    return false;
  }
}

this function is to send message $id is the id of receiver and $text is the text message.

To delete messages

        
 $message = sql_select("SELECT * FROM `Messages` WHERE `id`='" . sql_escape($id) . "' LIMIT 1");
 if (count($message) > 0 && $message[0]['SUID'] == $user['UID']) {
          sql_query("DELETE FROM `Messages` WHERE `id`='" . sql_escape($id) . "' LIMIT 1");
          redirect(page_link_to("user_messages"));
        } else
          return error(_("No Message found."), true);

Development: https://github.com/fossasia/engelsystem

Issues/Bugs:Issues