Here's my issue. During user register I'm adding fields via form_alter and creating a stripe account. When validation fails $form_state gets wiped out and when the user passes through validation again a second account gets created.
I'm thinking about using cache_set to hang on to the account info until the user gets through the registration process error free but is there a better way to do this?
It sounds like before your mymodule_form_validation($form, &$form_state) function returns you want to store the Stripe information in the users $_SESSION array as a valid attempt/data.
You write to user session using the global session value in PHP and Drupal adds it to the Users' DB/Mongo user session info at the end of page execution. For example:
// in your form validation code ...
$_SESSION['stripe_username'] = 'john_doe';
On form load simply prepopulate the form data from $_SESSION. Eg, you're stuffing the content into session because it will be wiped on form reload -- then you're replacing it so a 2nd account isnt created.
Another option for this particular use case may be
To set the form value during validation.
Use this function to change the submitted value of a form element in a form validation function, so that the changed value persists in $form_state through the remaining validation and submission handlers.
For example, on validation error, you could store the stripe ID in a '#type' => 'value' form element and thereby make it available for the subsequent request.
