Welcome! This is the notes page for our third learn-to-code-from-scratch meeting in McPhabbs (downstairs). The plan is to run something like this every two weeks to get people up and running with basic web development and system admin.

Adding this to the top of your programs will force errors to be displayed (as opposed to hiding them from general users). It might help find the source of your problem if you get an 'Error 500'.

error_reporting(E_ALL);
ini_set("display_errors", 1);

Just like last month, I'll spend some time taking anyone new through the basic set up steps. For those that are all set up and ready to go - we'll work on the following:

1. Create a simple quiz page. When you visit it, it chooses a random question from a list you've supplied earlier and asks for the answer in a form then checks if it's correct or not.
2. We'll build this using a simple array to begin with, then switch to getting the information from a database.

Skip through these if you're ready to start directly on the above, otherwise, these are the things we'll do, in order:

1. Setting up an Amazon EC2 instance - once that is complete you now have your own server, and you can securely connect to it using Putty (or directly via Linux/macOS)
2. Setting up your server with Apache and MySQL - the server doesn't have much software installed, just a basic terminal, these steps install Apache (the webserver) and MySQL (the database). At this step we also downloaded Adminer (a GUI to manage the database, similar to PHPMyAdmin).
3. Then we went through the Amazon AWS interface, and set up Security Groups for the webserver (HTTP) - this is basically Amazon's equivalent of a firewall, we had to open a port to allow access to our IP in a web browser
4. Writing your first hello world program - Now we started with our very first simple program.
5. Editing files remotely on the server - Then we looked at ways to connect directly to the server and edit files using Notepad++ (or by mounting a remote directory in Linux/macOS)
6. An example of a basic HTML form - We created a basic HTML form and showed how to access it's elements in PHP once it had been submitted
7. Some example code in PHP to connect to your MySQL server - Some others went ahead and got the PHP code working that connects to a database and pulls data out, though we stopped there as we hadn't actually put data into the database yet - maybe next time!

This uses elements from the basic form that we've already seen. We'll start just using an array of questions, then move to populating an array from a database.

First, the questions. Create a file called questions.php and enter something like this:

<?php

$questions[0]['question'] = "What was originally considered to be the ninth planet from the Sun but after 1992 had its status as a large planet changed?";
$questions[0]['answer'] = "Pluto";

$questions[1]['question'] = "How many days are there in February in a leap year?";
$questions[1]['answer'] = "29";

$questions[2]['question'] = "Give the four initials of the organisation responsible for maintaining a database of drivers in Great Britain?";
$questions[2]['answer'] = "DVLA";

$questions[3]['question'] = "Which dance move, in which the dancer moves backwards, was made popular by Michael Jackson?";
$questions[3]['answer'] = "Moonwalk";

?>

Now, a basic page to choose a question and random, and wait for the answer, let's call it quiz.php:

<?php

require("questions.php");

$size_of_question_list = sizeof($questions);

// check if we are in the middle of answering a question (if we are, then
// the random_number will already be set), otherwise, choose a number

if(empty($_REQUEST['random_number'])) {
   $random_number = rand(0, $size_of_question_list);  // there is a bug here
} else {
   $random_number = $_REQUEST['random_number'];
}


?>

<h1>Quiz</h1>

<?php

if(!empty($_REQUEST['user_answer'])) {
   $user_answer = $_REQUEST['user_answer'];
   $question_id = $_REQUEST['random_number'];
   echo "<p>You answered '$user_answer' for Question #$question_id</p>";

   if($user_answer == $questions[$question_id]['answer']) {
      echo "Correct :)";
   } else {
      echo "Wrong :(";
   }

}

?>

<p><strong>Question: </strong><?= $questions[$random_number]['question']; ?></p>
<form method='post' action='quiz.php'>
<input type='hidden' name='random_number' value='<?= $random_number; ?>' />
<input type='text' name='user_answer' />
<input type='submit' name='answer_button' value='Answer'/>
</form>

<p><a href='quiz.php'>Another random question</a></p>

1. Abdullah Khan
2. Aidan Rooney
3. Aileen McKenzie
4. Alan Kennedy
5. Allan Mullen
6. Angel
7. Ashir (Organiser)
8. Ben Davidson
9. Ben Ross
10. Benami Ark
11. Callum Tennant
12. Cesar Del Villar
13. Connor Bell
14. Cédric Chantreau
15. Ed
16. Erika Anderson
17. Gareth King
18. Hammy
19. Jack Hood
20. John Carlin
21. John Mason
22. Karola Jehodek
23. Kathryn M
24. Kevin
25. MaryF
26. meenakshi
27. Mike Nelson
28. Mohamed Ali
29. Nasir Hussain
30. Neil McKillop (Event Organiser)
31. Neil Wylie
32. Pavlo
33. Rameez
34. Rasika Purohit
35. Samuel Gallagher
36. Stephen Taylor
37. Steven
38. Victor Obonyo
39. Victoria B
40. Yasmin