Solved

keep user input in fields after unsuccessful form submission

Posted on 2016-11-13
2
67 Views
Last Modified: 2016-11-14
I have a validation function that checks user input. If the validation fails, unfortunately all the info they inputted disappears and they have to input everything again. This would annoy pretty much every user ever.

I tried something like this just to test out whether or not it would display the already inputted data. It works but it isn't very elegant. Is there  a better way? (This is just a test so there is no sanitizing etc.)

if(!isset($_POST['email'])) {
	$email = "";	
} else {
	$email = $_POST['email'];
}

<input type="text" name="email" class="form-control" value="<?php echo $email ?>">

Open in new window

0
Comment
Question by:Black Sulfur
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 110

Accepted Solution

by:
Ray Paseur earned 500 total points
ID: 41885488
Here is the design pattern.
https://iconoun.com/demo/form_highlight_errors.php
<?php // demo/form_highlight_errors.php
/**
 * Demonstrate how to highlight errors in form input, and remember valid inputs
 * Client is asked to put in a value
 * If the value fails our test we show an error message
 * We put a marker next to the input control on the form
 * We turn the form border red
 * SEE http://www.w3schools.com/CSS/pr_class_visibility.asp
 */
error_reporting(E_ALL);


// THESE STYLE ELEMENTS ARE SET FOR THE SCRIPT INITIALIZATION
$error_abc = $error_xyz = $error_any = 'hidden';
$boxer_abc = $boxer_xyz              = 'black';


// CAPTURE AND NORMALIZE THE POST VARIABLES - ADD YOUR OWN SANITY CHECKS HERE
$abc = (isset($_POST["abc"])) ? trim(strtoupper($_POST["abc"])) : NULL;
$xyz = (isset($_POST["xyz"])) ? trim(strtoupper($_POST["xyz"])) : NULL;


// IF ANYTHING WAS POSTED, VALIDATE IT
if (!empty($_POST))
{
    // VALIDATE THE 'abc' FIELD
    if ($abc != 'ABC')
    {
        // VALIDATION FAILED
        $error_abc = $error_any = 'visible';
        $boxer_abc = 'red';

        // BECAUSE THIS FAILED VALIDATION, REMOVE IT FROM THE FORM
        $abc       = NULL;
    }

    // VALIDATE THE 'xyz' FIELD
    if ($xyz != 'XYZ')
    {
        // VALIDATION FAILED
        $error_xyz = $error_any = 'visible';
        $boxer_xyz = 'red';

        // BECAUSE THIS FAILED VALIDATION, REMOVE IT FROM THE FORM
        $xyz       = NULL;
    }

    // DO WE HAVE INPUT FREE FROM ANY ERRORS?
    if ($error_any != 'visible')
    {
        echo "CONGRATULATIONS";
        die();
    }

    // OTHERWISE... OOPS - WE HAVE ERRORS AND MUST SHOW THE FORM AGAIN
}

// IF NOTHING WAS POSTED, OR IF THERE ARE ERRORS, WE NEED NEW CLIENT INPUT
$form = <<<ENDFORM
<style type="text/css" media="all">
.error_any { visibility:$error_any; }
.error_abc { visibility:$error_abc; }
.error_xyz { visibility:$error_xyz; }
</style>
<pre>
<form method="post">
<span class="error_any">PLEASE CORRECT THE FOLLOWING ERRORS</span>
<span class="error_abc">YOU MUST ENTER 'abc' IN THIS FIELD</span>
PLEASE ENTER "ABC" HERE: <input style="border-color:$boxer_abc;" name="abc" value="$abc" />
<span class="error_xyz">YOU MUST ENTER 'xyz' IN THIS FIELD</span>
PLEASE ENTER "XYZ" HERE: <input style="border-color:$boxer_xyz;" name="xyz" value="$xyz" />
<input type="submit" />
</form>
ENDFORM;

// WRITE THE FORM WITH THE APPROPRIATE CSS STYLES ON THE ERROR MESSAGE FIELDS
echo $form;

Open in new window

0
 
LVL 1

Author Closing Comment

by:Black Sulfur
ID: 41887337
Awesome, thanks!
0

Featured Post

Salesforce Has Never Been Easier

Improve and reinforce salesforce training & adoption using WalkMe's digital adoption platform. Start saving on costly employee training by creating fast intuitive Walk-Thrus for Salesforce. Claim your Free Account Now

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Nothing in an HTTP request can be trusted, including HTTP headers and form data.  A form token is a tool that can be used to guard against request forgeries (CSRF).  This article shows an improved approach to form tokens, making it more difficult to…
Many old projects have bad code, but the budget doesn't exist to rewrite the codebase. You can update this code to be safer by introducing contemporary input validation, sanitation, and safer database queries.
The viewer will learn how to count occurrences of each item in an array.
The viewer will learn how to look for a specific file type in a local or remote server directory using PHP.

717 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question