Required Form Elements

[TehLibrarian]

Hello all,

I'm terribly new at PHP so please bear with me. I've created an e-mail form for interlibrary loaning. The form works just fine but I have been unable to locate the proper way to make it so the form will require certain elements or not be sent. I'm not even sure if that is a PHP option. I would be grateful for any help. I'll include my code below (I know its overly simple.)

The things I wanted to make required were title, author, language, name, phone #, mailing address, library card #, and pickup location.

Thanks in advance.

<?

$title = $REQUEST['title'];
$author = $REQUEST['author'];
$pub = $REQUEST['pub'];
$edit = $REQUEST['edit'];
$oclc = $REQUEST['oclc'];
$not = $REQUEST['not'];
$type = $REQUEST['type'];
$lang = $REQUEST['lang'];
$name = $REQUEST['name'];
$phone = $REQUEST['phone'];
$email = $REQUEST['email'];
$libcard = $REQUEST['libcard'];
$branch = $REQUEST['branch'];
$address = $REQUEST['address'];

$message = "
Name: $name
Phone#: $phone
Address: $address
Library Card: $libcard
Branch: $branch
Title: $title
Author: $author
Publisher: $pub
Edition: $edit
OCLC: $oclc
Not Needed After: $not
Type: $type
Language: $lang";
// prevent email header injection:
$header = "From: " . preg_replace('/[\r\n]+/', '', $email);
mail("[e-mail]", "ILL Form", $message, $header);
header( "Location: URL" );
?>

[The_Chancer]

if (!isset($_REQUEST['var']) || $_REQUEST['var']=='')
{
    //deny
}

Is one method

[TehLibrarian]

Thank you, I'll give that a try. 🙂

[NogDog]

You can use [man]empty/man:

if(empty($_POST['field_name']))
{
   // input error
}

However, note that this and the preceding suggestion will both give a false negative if "0" (zero) is entered in a field and that is a valid entry. Also, they may give false positives if the field just contains one or more spaces. What I usually use if I just want to verify that something was entered (other than spaces):

// note use of === rather than ==
if(!isset($_POST['field_name']) or trim($_POST['field_name']) === '')
{
   // nothing was input
}

[TehLibrarian]

Does the

// note use of === rather than ==
if(!isset($POST['field_name']) or trim($POST['field_name']) === '')
{
// nothing was input
}

go at the end of the PHP document? Or right after the field in question?

[NogDog]

It goes at a point in your PHP form-handling script where you want to validate the input.

[TehLibrarian]

Okay. Thank you for the help.