PHP - 表单：保存表单提交中的条目/选择

Question

I have a PHP form that has some drop down selections and text field entries. If the user selects the wrong item from the dropdown, when they submit the form, I have it so that it will show an error message to the user and force the browser to go back to the previous page. The problem is that the user has to re-enter all of the information.

How do I make the form save the data until the form submit is successful?

EDIT:

Form submit method is $_POST and the form is being submitted to another page.

This would have to be done with strictly PHP as Javascript/Jquery solutions can be script blocked by more secure users.

Answer 1

Here you go. This will work, and is not dependent on Javascript:

form.php //the form page

<?php session_start(); ?>
<form method="post" action="action.php">
    <input type="text" id="input1" value="<?php echo (isset($_SESSION['fields']) ? $_SESSION['fields']['input1'] : '') ?>" />
    <input type="text" id="input2" value="<?php echo (isset($_SESSION['fields']) ? $_SESSION['fields']['input2'] : '') ?>" />   
</form>

action.php //the action page

<?php
    session_start();

    //do your validation here. If validation fails:

    $_SESSION['fields']['input1'] = $_POST['input1'];
    $_SESSION['fields']['input2'] = $_POST['input2'];

    //redirect back to form.php
?>