Form validation and Error Message

[Skor]

 

I've got one that has me scratching my head, not sure exactly how to do this. I've got a drop down menu that I would like to consider mandatory. If it's not selected, I'd like to display an error on the page close to the drop-down, if it is selected, the form should post to another page.

 

I've tinkered with a little javascript which I couldn't figure out. I've used a switch to display different dropdowns and that works fine, I've just included one as an example. Here's what the form looks like:

 

 

<FORM NAME="CORDS" METHOD="POST" ACTION="checkmeout.php">
<INPUT TYPE="HIDDEN" NAME="product" VALUE="<?php echo $item3; ?>">
<INPUT TYPE="HIDDEN" NAME="price" VALUE="<?php echo $price; ?>">
<INPUT TYPE="HIDDEN" NAME="pagetype" VALUE="neck">

switch ($neck) {
case "A":
echo " 
<input type=\"hidden\" name=\"product[]\" value=\"$item3\">
<select name=\"product[]\"><option value=\"\">Select your cord or chain:</option>
<option value=\"18-inch silver chain\">18-inch Sterling silver box chain</option>
<option value=\"16-inch black cord\">16-inch black rubber cord</option>
<option value=\"18-inch black cord\">18-inch black rubber cord</option></select>";
break;
}
?>
<br><br>Include giftbox
<input type="checkbox" name="giftbox" value="giftbox"> 

<INPUT TYPE="SUBMIT" Value="Add to Cart"> </FORM>

[schme16]

I find using

foreach($_POST as $post)
{

if($post==NULL){print 'You have left fields blank!';}

}

 

usually does the trick, however it will check all of the posted variable to check its contents isn't null (there is a way to make it specific but unless you need it don't bother... if you need it specific then just ask and I'll give you the longer piece for that)

[Skor]

Yes, I do need to make it specific to the drop down.  The check box is an option and can be null.  Thanks much.

[wildteen88]

If you only want to validate the pull down, You'll want to use something like the following:

if(!isset($_POST['product'][1]) || empty($_POST['product'][1]))
{
    echo 'You must select a product from the pulldown menu';
}

 

[Skor]

Where do you put the "if" statement -- at the top of the form, bottom, outside of the form tags.  Just curious.  Tinkering with your suggestion and haven't gotten it to work yet....

[darkfreaks]

in the php tags at the top

[wildteen88]

Where do you put the "if" statement -- at the top of the form, bottom, outside of the form tags.  Just curious.  Tinkering with your suggestion and haven't gotten it to work yet....

That code will go into the script which processes the form when it is submitted. Looking at your forms action tag the script which processing the form is checkmeout.php

[Skor]

I was hoping to put the error on the form itself, near the drop-down...is that possible to do.  If not, I can certainly put it on the post page, which I'll try this evening.  Thanks.

[wildteen88]

Yes you can do this however you you'll need to change the forms action, so it submits to itself (the page the form is displayed on) rather than getting submitted to another page.

 

Example:

<?php

$error = null;

// form validation:
if(isset($_POST['name']) && empty($_POST['name']))
{
    $error[] = 'Please fill in the name field';
}

if(isset($_POST['age']) && empty($_POST['age']))
{
    $error[] = 'Please fill in the age field';
}


// display errors if there is any:
if(is_array($error))
{
    echo 'Please correct the following:<br />';
    echo '<ul><li>' . implode('</li><li>', $error) . '</li></ul>';
}
?>
<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post">
Name: <input type="text" name="name" /><br />
Age: <input type="text" name="age" /><br />
<input type="submit" name="submit" value="Submit" />
</form>