Coursework 2 - Part 3

Today I am going to talk about the last part of my course work. After nearly finishing my coursework, I got an idea to make the game more interesting. I added a feature that checks if a player beats the current high score, and the current high score was achieved by another player, the game sends an email to the other player to tell him or her that her score was beaten.

Modifying the database

Even though this was not very difficult to do, it took me a whole week to manage to sort it out. First, I added a field in the database of the users to add the email address of the player. This requires the email to be added manually to the database as a new user cannot add an email address in the login form. This was done without because the scope of the login page was not to create a fully featured login form with a registration form.  So, I added an email address to each record in the database. For testing purposes, I inserted my email address in all the fields so that I would not bug other people with my emails.

Checking if the highest score was beaten by another player

Then, I started to modify the function which compares the high scores. After opening the connection with the database, I made a query to obtain the username, the high score and the email of the person who is at the top of the hall of fame.  The query which I used is shown below:

select username, highscore, email

from cannon_game.login    

order by highscore desc limit 1;

The record obtained is inserted into the variable $row and from it I obtained a value for the $topuser, $topscore and $topemail, which are the details of the player with the highest score in the hall of fame. Then an if statement checks if the current score is larger than the $topscore value from the database. If the score is higher than the topscore, the difference is calculated. Then, another if statement checks if the current player is the topuser. If it is not the same user, then it means that the person who was first, now moves to second place. Then, a function called email is called and it is passed the values for topuser, topemail and the score difference. Then the function continues to update the scores accordingly like it used to do before.

Testing this function

Knowing that emailing would not work immediately, I tested this function a bit primitively, using echo. I tested by using different users to play the game and trying to achieve a better score every time. I was not playing the game to obtain the highest possible score. I tried to keep scores low so I would not have to reset the scores from the database because I would not be able to beat them. By echoing the variables values I knew that the function to check if the high score was beaten by another player was working great.

Email function

I created the email function and I passed to it the variables $topuser, $topemail and $scoredifference. To send emails you need a to address to send emails to, a from address, a subject and a body. The to email was obtained from the database and passed to the function. I used my personal email as the from email address. Then I crafted a subject and a body message using the user name and the score difference. The code below shows the first part of the email function:

     $to = $topemail;

     $from = "danielborgmt@gmail.com";

     $subject = ucwords($topuser).", be careful!!";

     $body = ucwords($topuser).", your score was beaten by "                   .$scoredifference." points!! Make sure to beat his score to          stay in the first place!!!";

The function ucwords() is used to capitalize the first letter of the string passed to it. Then you need an SMTP server to be able to send emails. This gave me a lot of problems and took me nearly a week to solve. I talked about this in my previous blog. After trying a lot of solutions, I managed to find a working script which worked nearly immediately. The script was a PEAR extension and I used the following code to be able to use it:

     $er = error_reporting(0);

     require_once "Mail.php";

SMTP Server Settings

The error_reporting(0) is used to hide errors for using methods which were not called using a STRICT method. This was done at the top of the php file. After enabling SSL on my web server, I added the details of my Gmail account to use Gmail's SMTP server. Then I called the function to send the email to the details of the player who was first using my Gmail SMTP server. The code is shown below:

     $host = "ssl://smtp.gmail.com";

     $port = "465";

     $username = "danielborgmt";

     $password = "mypassword";

     $headers = array ('From' => $from, 'To' => $to, 'Subject' =>                         $subject);

     $smtp = Mail::factory('smtp', array ('host' => $host,'port' => $port, 'auth' => true, 'username' => $username, 'password' => $password));

     $mail = $smtp->send($to, $headers, $body);

          

     if (PEAR::isError($mail)) {

          echo("<p>" . $mail->getMessage() . "</p>");

     }

This code allowed me to send emails properly to the player who lost the first place.

Figure 1: Sample Email from PHP Script

Figure 2: Email details

This concludes my second coursework.