PDA

View Full Version : Reading input from form elements

Clueless_Coder
10-28-2007, 07:37 PM
I am a complete newb to PHP and frankly programming in general.

I am working through a book I purchased called PHP 5/MySql Programming for the "Absolute Beginner" :rolleyes:

That's not really important other then just to say I'm beginning to get perturbed and believe this book is full of coding errors. :mad:

The exercise I am working on now is supposed to take information you enter into a form, and provide you with a PHP output. (I've got my Apache/PHP installed, and it's worked fine on the other couple of exercises)

I will now post the code for the two files that you are supposed to create. (Note that I am actually posting you the exact code from the author, not my own which neither worked).

As it stands now, when I submit the form borderMaker.html it sends me back the second file, borderMaker.php. All that is shown on the browser is the < h1 > Your Output at the beginning of the second file. None of the PHP script appears.


Form file "borderMaker.html"
<html>
<head>
<title>Border Maker</title>
</head>
<body>
<center>
<h1>Border Maker</h1>
<h3>Demonstrates how to read HTML form elements</h3>

<form method = "post"
action = "borderMaker.php">


<h3>Text to modify</h3>
<textarea name = "basicText"
rows = "10"
cols = "40">
Four score and seven years ago our fathers brought forth on this
continent a new nation, conceived in liberty and dedicated to the
proposition that all men are created equal. Now we are engaged in a
great civil war, testing whether that nation or any nation so
conceived and so dedicated can long endure.
</textarea>

<table border = 2>
<tr>
<td><h3>Border style</h3></td>
<td colspan = 2><h3>Border Size</h3></td>
</tr>

<tr>
<td>
<select name = borderStyle>
<option value = "ridge">ridge</option>
<option value = "groove">groove</option>
<option value = "double">double</option>
<option value = "inset">inset</option>
<option value = "outset">outset</option>
</select>
</td>
<td>


<select size = 5
name = borderSize>
<option value = "1">1</option>
<option value = "2">2</option>
<option value = "3">3</option>
<option value = "5">5</option>
<option value = "10">10</option>
</select>
</td>

<td>
<input type = "radio"
name = "sizeType"
value = "px">pixels<br>
<input type = "radio"
name = "sizeType"
value = "pt">points<br>
<input type = "radio"
name = "sizeType"
value = "cm">centimeters<br>
<input type = "radio"
name = "sizeType"
value = "in">inches<br>
</td>
</tr>
</table>

<input type = "submit"
value = "show me">


</form>

</center>
</body>
</html>

PHP Output File "borderMaker.php"
<html>
<head>
<title>Your Output</title>
</head>
<body>
<h1>Your Output</h1>
<center>
<?
$theStyle = <<<HERE
"border-width:$borderSize$sizeType;
border-style:$borderStyle;
border-color:green"
HERE;

print "<div style = $theStyle>";
print $basicText;
print "</span>";

?>
</center>

</body>
</html>

On an earlier exercise, there was a problem that involved the "Register Globals" option in the PHP.ini file. Not sure if that has anything to do with why this exercise won't work or not.

It's frustrating that even that author's code will not work, and I would greatly appreciate someone with experience to take a look and see if they can figure out why I might be having troubles. Thanks again.
CFMaBiSmAd
10-28-2007, 08:20 PM
The problem is with register globals, however, don't turn them on to solve this. Learn how form data should be accessed in your code.

When the form method is POST, the input fields will be present in the $_POST array. Use the following code to display the entire contents of the $_POST array to see what it contains -
echo "<pre>";
print_r($_POST);
echo "</pre>";

Register globals were turned off by default in php 4.2 some time in the year 2002. No new code, tutorials, or books should have been written after that point in time that relied on them being on. Register globals have been completely eliminated in PHP6. The reason they were turned off and are being eliminated is because they were a huge blunder and a security problem. By "magically" populating same name program/GET/POST/COOKIE/SESSION variables, you don't know where an actual value came from and this allowed program and session variables (which you would hope a visitor could not change) to be modified by simply putting parameters on the end of the url. There have even been several recent posts here where values in session variables have been overwritten by simply having a form field with the same name, causing unexplained operation of the code.
Clueless_Coder
10-28-2007, 08:38 PM
I went in and added the code you posted to my script as the following:

"borderMaker.php"

<?
$theStyle = <<<HERE
"border-width:$borderSize$sizeType;
border-style:$borderStyle;
border-color:green"
HERE;

print "<div style = $theStyle>";
print $basicText;
print "</span>";
echo "<pre";
print_r($_POST);
echo "</pre>";

?>

When I submit the form, I now get this output.

Your Output
Four score and seven years ago our fathers brought forth on this continent a new nation, conceived in liberty and dedicated to the proposition that all men are created equal. Now we are engaged in a great civil war, testing whether that nation or any nation so conceived and so dedicated can long endure. [borderStyle] => double [borderSize] => 10 [sizeType] => pt )

Is this the $_POST array?
[borderStyle] => double [borderSize] => 10 [sizeType] => pt )

How can I go about using this to make the border function work?
Thanks. Sorry for my stoopid questions. :o
CFMaBiSmAd
10-28-2007, 09:12 PM
Yep. The corresponding post variables are -
$_POST['borderStyle']
$_POST['borderSize']
$_POST['sizeType']
Clueless_Coder
10-28-2007, 09:47 PM
How would I work that into my code to make it work?
jlhaslip
10-28-2007, 11:13 PM
<?
$borderSize = $_POST['borderStyle'];
$sizeType = $_POST['borderStyle'];
$borderStyle = $_POST['borderSize'];

$theStyle = "border-width:$borderSize$sizeType; border-style:$borderStyle; border-color:green"

print "<div style = $theStyle>";
print $basicText;
print "</span>";
echo "<pre";
print_r($_POST);
echo "</pre>";

?>
Clueless_Coder
10-28-2007, 11:24 PM
jihaslip,

When I run the following code in my borderMaker.php file I still get the same thing.

Using this,
<html>
<head>
<title>Your Output</title>
</head>
<body>
<h1>Your Output</h1>
<center>
<?
$borderSize = $_POST['borderStyle'];
$sizeType = $_POST['borderStyle'];
$borderStyle = $_POST['borderSize'];

$theStyle = "border-width:$borderSize$sizeType; border-style:$borderStyle; border-color:green";

print "<div style = $theStyle>";
print $basicText;
print "</span>";
echo "<pre";
print_r($_POST);
echo "</pre>";
?>
</center>

</body>
</html>

Still gets me this output
Your Output
Four score and seven years ago our fathers brought forth on this continent a new nation, conceived in liberty and dedicated to the proposition that all men are created equal. Now we are engaged in a great civil war, testing whether that nation or any nation so conceived and so dedicated can long endure. [borderStyle] => ridge [borderSize] => 3 [sizeType] => cm )