How to retain $_POST data when submitting form to custom page

Question

I have written a plugin whose job is to create a custom page with a user subscription form. The form page is created like this:

$page = [                              
    'post_type' => 'page',             
    'post_content' => '',              
    'post_status' => 'publish',        
    'post_title' => 'Create a new account', 
    'post_name' => 'account new'        
];                                     
                                       
$page_id = wp_insert_post($page);     

This creates a new page at http://example.com/account-new/ that renders a subscription sign up form. I used the same process to create a page that receives the POST data at http://example.com/account-pending/.

In my theme, which is independent of the plugin, the form's opening tag looks like this:

<form method="post" id="new-account-form" action="/account-pending/">

On submit, I can see in Chrome that the post data are sent to the account-pending page, but when I debug the PHP code with PHPStorm I find that the $_POST object is not set.

The /account-pending/ page contains the following function that is meant to process the POST data:

public function get_account_pending()
{

    if (isset( $_POST['my_check_value'])) {
        $username =       $_POST['username'];
        $password =       $_POST['userpass'];
        $firstname =      $_POST['firstname'];
etc...

I have also added an action for capturing the post action with

add_action( 'wp', array( &$this, 'get_account_pending' ) );

but I am still missing something. How do I find what is stripping away the $_POST object? At this point in the code only the following variables are set:

$this
$_GET
$_REQUEST
$_SERVER
$GLOBALS

Am I missing a step somewhere that is required to properly set up the POST data for receiving it on the /account-pending/ page?

Edit:

I am able to see the $_POST data if I send the data via a cURL command as below:

curl -X POST 'firstname=myfirst' -F 'lastname=mylast' -F 'username=username21' -F 'usermail=me%40example.com' -F 'userpass=thisone' -F 'userpass_again=thisone' -F 'my_check_value=on' -F 'billing_address=452+Kennebec+Rd' -F 'billing_apt=' -F 'billing_city=Heretown' -F 'billing_state=ME' -F 'billing_zip=04444' -F 'card_type=4' -F 'card_number=4111111111111111' -F 'expire_month=07' -F 'expire_year=23' http://example.com/account-pending/?XDEBUG_SESSION_START=10663

This seems to indicate that the problem lies with either wordpress (or PHP) clearing the $_POST variable, or that my form is not submitting the data properly.

Answer 1

I don't know why your $_POST data disappears. However, consider using the admin_post/admin_post_nopriv hook to process the form data using a function on the back end. That's what the function was made for. At the end of the function, you can then redirect to the account-pending page using this wp_redirect(home_url('/account-pending')) .