form validation advice !!

[fimbria]

hello,

i have construct a standard form, which i want to validate, what im really asking how it is best to structure the script?

for example

//form (with name, email & message)
//on submit check each field

if($name=""){
print"please add your name";

}
if($email=""){
print"please add your email";

}

if($message=""){
print"please add your message";

}else{

//add to database


}

does this look like a good way to structure the vaildation? if not can you give me some ideas, PLEASE !!

thanks for your time in advance

[batman]

You can use this:

$name = $_POST['name'];
$email = $_POST['email'];
$message= $_POST['message'];

if(empty($name) || empty($email) || empty($message))
{
echo "I'm sorry, you did not fill out all the required information";
if($name = "")
{
echo "Name is a required field!";
}
if($email = "")
{
echo "Email is a required field!";
}
if($message = "")
{
echo "Message is a required field!";
}
include("page.php");
exit();
}
else
{
echo "<font color=red><b>You filled in all the required fields. THANK YOU!</b></font>";
}

Hope that helps,

[fimbria]

thanks "batman" for your help, just got a few queries to ask:

1. why do i need the "exit();" command? (well i known what its for but, why in the code)

2. where would i put my query? after the else statement?

thanks again....

[batman]

I put the exit(); in there that way if you have any other stuff you want to put below the validation, it wont run if they make a mistake.

What kind of query are you wanting to run? If this is for a log-in script and you are wanting to validate the info compared to the database then you will put the query at top.

Let me know,

[fimbria]

well to start, im using the validation to check a guestbook form (basically to check the content before adding the details to the database)...

but once i have used the validation for the guestbook, i do want to use the vaildation on the login page..(as i have previously used javascript on this page, as you know people can switch off javascript so that validation isn't very secure).

thanks again

[laserlight]

Actually, you shouldnt do quite what batman said.

For one thing, you should use empty() on the incoming variables before assigning them to other variables.
For another, you should use == to check, not =
In this case, one might as well just keep on using empty()

e.g.

if (empty($_POST['name']) || empty($_POST['email']) || empty($_POST['message']))
{
	echo "I'm sorry, you did not fill out all the required information";
	if (empty($_POST['name']))
	{
		echo "Name is a required field!";
	}
	if (empty($_POST['email']))
	{
		echo "Email is a required field!";
	}
	if (empty($_POST['message']))
	{
		echo "Message is a required field!";
	}
	include("page.php");
	exit();
}
else
{
	echo "<font color=red><b>You filled in all the required fields. THANK YOU!</b></font>";
}

[fimbria]

im planning on having the form on the page, then as i explained earlier, have the validation, which would be displayed underneath the form, once the form has been submitted.

would it take must to re-display the field that the user has entered, that validated "ok"?

thanks

[laserlight]

You can use the value attribute in input elements.

e.g.

<input type="text" name="somename" value="<?php
if (!empty($_POST['somename']))
	echo htmlspecialchars(stripslashes($_POST['somename']));
?>">

the form is submitted to itself, i.e. action is set to $_SERVER['PHP_SELF']

[fimbria]

Hi again,

Thanks for the help given with the vaildation..

Just have a little problem... im using the following code:

<textarea cols="40" rows="10"
name="txtaMessage" value="<?php if (!empty($POST['txtaMessage']))
echo htmlspecialchars(stripslashes($POST['txtaMessage']))
;
?>"> </textarea>

But the problem im having, is when the page is shown the "textarea" field starts a few charcters in, so this means that the field logically thinking is not empty, so the vaildation "ok" this when it should not.

Can anyone see what is wrong with the code that is causing this problem?

thanks again.

[Percadan]

Try this.

The value of $txtaMessage must be between <textarea></textarea>

<textarea cols="40" rows="10"
name="txtaMessage">
<?php if (!empty($POST['txtaMessage']))
echo htmlspecialchars(stripslashes($POST['txtaMessage']));?>
</textarea>

[fimbria]

yeah, thanks...

i found that out...i was trying to enter the value as a normal text field.