Pass arguments to hook_form_alter()

Question

I have two login boxes on the same page and, I would like to integrate different behaviors to those based on some arguments.

I'm calling myself the forms with drupal_get_form('user_login');. I would like to pass a variable to the form:

drupal_get_form('user_login', $myvar);

And then be able to get it from a hook_form_alter():

function mymodule_form_alter($form, $form_state, $form_id, $myvar) {
  // some code here
}

But i can't find a way to do this.

Answer 1

The passed arguments are kept in $form_state['build_info']['args']. You can find a documentation of the $form_state structure here: drupal_build_form().