Autofilling form values in PHP/HTML-CodePudding

In a PHP web page, when flling the form and some of the fields are filled incorrectly, I need to return to the same page and auto-fill all the fields that were prefiously filled by the user. How do I set the values of the fields?

I tried using the $_POST method and echo but the error was that the key I used was undefined.

CodePudding user response：

Remember, if you do use echo then make sure you escape the output, ie

echo htmlspecialchars($_POST['name']);

otherwise you risk injection attacks

CodePudding user response：

You can store values in an array called data$ And if there is an error, return this array to the page and use the value method to fill in the pre-filled values. Example

    $data =[
 'name' => $_POST['name']
 ];
 if(empty($data['name']){
 $data['name_err']= "error name";
 }

And on the desired page:

 <input value="<?php echo $data['name'] >?">
 <span><?php echo $data['name_err'] <span>

CodePudding user response：

 You can use a session to store the form values.

    <?php
    // Start the session
    session_start();
    
    // Store values in session//
    $_SESSION['form'] = ['first_name' => isset($_POST['first_name']) ? $_POST['first_name'] : '', 'last_name' => isset($_POST['last_name']) ? $_POST['last_name'] : '', ];
    ?>


<input name="first_name" value="<?php echo isset($_SESSION['form']['first_name']) ? htmlspecialcharc($_SESSION['form']['first_name']) : ''; ?>">
<input name="last_name" value="<?php echo isset($_SESSION['form']['last_name']) ? htmlspecialcharc($_SESSION['form']['last_name']) : '' ?>">