HTML and CSS Reference
In-Depth Information
print out the
<input>
tags, using
toys[]
as the parameter name to let PHP know that this
field can have multiple values and should be treated as an array. To include the value for
a field, I just use a short tag to insert the key into the
value
attribute of the tag. I use it
again to print out the label for the check box,
$value
, after the tag. The last bit here is
the
if
statement found within the
<input>
tag. Remember that if you want a check box
to be prechecked when a form is presented, you have to include the
checked
attribute. I
use the
in_array()
function to check if the key currently being processed is in
$_POST['toys']
. If it is, I then print out the
checked
attribute using
echo()
. This
ensures that all the items the user checked before submitting the form are still checked if
validation fails.
A browser displaying a form that contains some errors appears in Figure 21.2. Here's the
full source listing for the page:
Input
▼
<?php
$toys = array('digicam' => 'Digital Camera',
'mp3' => 'MP3 Player', 'wlan' => 'Wireless LAN');
$errors = array();
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
$errors = validate();
}
function validate() {
$errors = array();
if (empty($_POST['name'])) {
$errors['name'] = 'You must enter your name.';
}
if (!is_numeric($_POST['age'])) {
$errors['age'] = “You must enter a valid age.”;
}
if (empty($_POST['toys'])) {
$errors['toys'] = 'You must choose at least one toy.';
}
21
return $errors;
}
?>
<!DOCTYPE html>
<html>
<head>
