Add extra field when admin create user

Question

I have created extra field that user can edit on their 'Your Profile' page. The extra field also available on WordPress register page. What I want to ask is, how to add the field to User > Add new page ? So, when admin creates a user, admin also input the user's extra field

Answer 1

With no hooks on that page (User > Add new page) other then user_new_form_tag its not possible to add new fields unless you hack the core file wp-admin/user-new.php .

You could try adding that extra field by adding in in JQuery and processing it when the $_post['action'] == 'adduser' but that wont be very good practice.

Answer 2

I was able to do this through a rather fragile hack. It uses the output buffer to insert the new field. Thankfully there's a nice hook to save the field.

// FRAGILE!  This rewrites code directly in the buffer, upgrading WP may break this
function wpse18772_add_fields( $buffer ) {
  $input_html = '<input type="text" name="your-new-field" id="your-new-field">';

  // will insert a new field after "role"
  $buffer = preg_replace( '~<label\s+for="role">(.*?)</tr>~ims', '<label for="role">$1</tr><tr class="form-field"><th>My New Field</th><td>' . $input_html . '</td></tr>', $buffer );

  return $buffer;
}

function wpse18772_buffer_start() { ob_start("wpse18772_add_fields");  }
function wpse18772_buffer_end() { ob_end_flush(); }
add_action('admin_head', 'wpse18772_buffer_start', 10, 1);
add_action('admin_footer', 'wpse18772_buffer_end', 10, 1);

function wpse18772_save_fields($user_id) {
  if($_POST['action'] != "adduser" && $_POST['action'] != "createuser") return;

  if(!empty($_POST['your-new-field'])) {
    // save field to meta, or do whatever you want to here
  }
}
add_action('user_register', 'wpse18772_save_fields');

Answer 3

See this answer. There are no hooks, but you can do it with jQuery. Simply add your html markup with jQuery and it will be done.