Set default value radio button in template

Question

I'm trying to set a default value in a template file for a radio button on my register form.

Female has value 0 and male has value 1. This is the code I use to set a default value:

    $form['field_personal_details']['und'][0]['field_gender']['und']['#default_value'] = '1';

I also tried

    $form['field_personal_details']['und'][0]['field_gender']['und']['#value'] = '1';

This should check the radio button as male, but it doesn't work. Whenever I set the default value to male through the UI it does work and I get the same outputs when I do a dpm.

What am I doing wrong?

Answer 1

Add direct user registration form alter and try to change "1" to 1.

function MYMODULE_form_user_register_form_alter(&$form, &$form_state,$form_id) 
{

  $form['field_gender']['und']['#default_value'] = 1;
    <---or ---> 
  $form['field_personal_details']['und'][0]['field_gender']['und']['#default_value'] = 1;

}

Answer 2

You need to use hook_form_alter() (or hook_form_FORM_ID_alter()) to alter forms:

function MYMODULE_form_alter(&$form, &$form_state, $form_id) {
  if ($form_id == 'foo') {
    $form['field_personal_details'][LANGUAGE_NONE][0]['field_gender'][LANGUAGE_NONE]['#default_value'] = '1';
  }
}