Networks & Transactions 1

Monday, February 6

Lab concepts:

Basic HTML
Embedding PHP in HTML
Generating HTML with PHP
Using an HTML form to pass input arguments (parameters) as a request to a PHP program

This now corresponds better to how things are done in Boudreaux, since we've left the Terminal and moved to generating HTML for web browsers.

Lab corresponds to:

Boudreaux pp 34, 166-175, 180 (chapter 6 is all about using HTML forms, including some more advanced aspects)

3a-request.php Run in web browser

<html>

<head>

<title>
I would like to read your mind
</title>

</head>

<body>


<img src="http://www.bmaent.com/Kreskin.gif" width="100" height="150">


<h1>I will guess your name.</h1>



Please,<br>
tell <a href="http://google.com">me</a> your <a href="1-hello.php">age</a>.




<p>Then I will guess <i>your <b>name.</b></i></p>


<p>I am an      ámazing      guesser.</p>





<form action="3b-respond.php" method="get">


Tell me your age... <input type="text" name="age">

<br>


Ok please also tell me what you had for lunch. <input type="text" name="lunch" value="Cookies?">

<br>


<input type="hidden" name="ourSecret" value="<?php echo rand(0, 100); ?>">


<input type="submit" value="Proceed...">

</form>

</body>

</html>

3b-respond.php

<html>

<head>
<title>I have ascertained your name.</title>
</head>

<body>

<h1>I am thinking...

<?php

// Make an array of names
$allTheNames = array("Yoonjai", "Mimi", "Ian", "Eric", "Rebecca", "Tom", "Sam", "Geoff", "Laitsz", "Kate", "Emily", "Tom", "Dan", "Sebastian", "Ken", "Eric", "Bethany", "Nick", "Andrew", "Gabby", "Rob", "Dave", "Wei");

// count($allTheNames) is 22 because there are 22 elements in the array
// But in the array they are numbered 0 through 21, so choose a random number between 0 and 21 inclusive.
$chosenNameIndex = rand(0, count($allTheNames) - 1);

// The $_REQUEST[] array contains all parameters passed to this script as part of a "get" or "post" request
// Make sure the "age" parameters has been passed to this script before we proceed, and also make sure it's a number greater than 0
if (isset($_REQUEST["age"]) and (intval($_REQUEST["age"]) > 0)) {

// Store the parameters in more meaningful variable names
// Also convert age to a number, since PHP would treat all parameters as strings by default
$userAge = intval($_REQUEST["age"]);
$userLunch = $_REQUEST["lunch"];
$theBigSecret = $_REQUEST["ourSecret"];

?>

Ok I have it.</h1>

<?php
// Notice we can go in and out of PHP blocks whenever we want, switching between HTML and PHP.
// We can also output HTML from within a PHP block, using echo statements.

// Figure out what name is at $chosenNameIndex (the random number we chose previously)
$chosenName = $allTheNames[$chosenNameIndex];

// Output HTML to display it, and also display the other things we know
echo "I think, your name is <b>$chosenName</b>!";
echo "<p>Right?</p>";

echo "Unbelievably, I also know that you are $userAge years old.<br>";
echo "And you ate $userLunch for lunch.<br>";
echo "Our secret: $theBigSecret";

}

// Print an error message if age wasn't specified or couldn't be understood as a number > 0
else {

echo "I must know your age in order to determine your name.</h1>";

}

?>

</body>

</html>

Lab3