I have been working on a form that uses PHP form validation. I also have a class in my CSS file that should be added to each of the invalid inputs. You can view a JSFiddle here. The class I am trying to add is only visible when the input is returned invalid. The class name is .invalid which you can find in the CSS. Thanks in advance, and any help is appreciated.
2 Answers
You can have PHP add a class to your inputs if a field is invalid, but you may need to adjust your approach.
If you want to maintain using a form POST method (as you have it), you'd want to move your validation code to be processed on the same page that renders your view (the easiest way to do this is to have it within the same page). You can still use and include a separate file to pull in a PHP class or other system you want to use for validation if you want to keep your code neat. Here's an example:
<?php
// filter_input returns null or false if invalid.
$firstname = filter_input(INPUT_POST, 'firstname', FILTER_SANITIZE_STRING);
?>
<form method="POST" action="<?php echo getenv('REQUEST_URI'); ?>">
<input type="text" name="firstname" value="<?php echo $firstname; ?>" class="<?php echo $firstname ? '' : 'invalid'; ?>" />
<input type="submit" name="submit" value="Submit" />
</form>
However, I would recommend a more robust approach which would be to use an AJAX handler for submitting your form. This will give your users a better experience, and it also allows you to neatly have your form processing entirely separate from your view. That solution is a bit beyond the scope of this question, but ultimately you would have your PHP AJAX handler return information as to whether or not the submission was valid or what fields are invalid and have the javascript add your invalid class to the fields in error.
1 Comment
Lawrence Johnson
I recommend to all PHP devs to look into the
filter_input function for capturing form values. Here is an article explaining a bit about it and form security in general. dev.to/lawrencejohnson/improving-form-and-ajax-security-4g29Let's assume there are two inputs and as you want to validate via PHP the validation process will be after submitting the form as
HTML
<input type="text" title="First Name" aria-placeholder="First Name" id="name" required />
<input type="text" title="Last Name" aria-placeholder="Last Name" id="name" required />
PHP
for($i = 0;$i < sizeof($_POST);$i++){
if($_POST[$i] == null || $POST[$i] == ""){
echo "Please insert :".$_POST[$i];
}
}
Note: PHP will validate the form after the form has been submitted for the validation before the submission you will need use javascript.
5 Comments
IPSDSILVA
So does this add the class of
.invalid into the invalid input, or does it just say "Please insert: ..."?
Kunal Raut
PHP cannot add the class for you for that you will need javascript because while handling forms PHP validates the form after the form has been submitted.
Kunal Raut
See as your question tells you need php to do this work but it can't because php is a server side language and javascript is a client side hence it only can be done by javascript.
Kunal Raut
If my answer helped can you please accept it as answer?
Kunal Raut
Thanks a lot glad to help you:)
novalidateattribute to theformelement? So, the HTML doesn't add its own validation?novalidateattribute, but give it a shot? perhaps remove any validation orrequiredattributes from your form elements..invalid(this class is described in CSS of having dark red border and red background). That's why I was wondering if there was a way to add classes with PHP.