frm_filter_final_form

You can use this this example code to place opening and closing shortcode tags to span throughout HTML fields in the form. This particular example shows how to use the shortcode for the Hide This plugin.

add_filter( 'frm_filter_final_form', 'filter_hide_this' );
function filter_hide_this( $form ) {
  global $shortcode_tags;
  $original_shortcodes = $shortcode_tags;
  $limited_shortcodes = array( 'hidethis' => $shortcode_tags['hidethis'] );
  $shortcode_tags = $limited_shortcodes;
  $form = do_shortcode( $form );
  $shortcode_tags = $original_shortcodes;
  return $form;
}

add_filter( 'frm_do_html_shortcodes', '__return_false' );

The easiest way to minimize the form HTML is by adding minimize=1 to your [formidable] shortcode. But if every form on your site needs to be minimized, you can strip out the white space before it can be converted to <p> or <br/> tags with this:

add_filter( 'frm_filter_final_form', 'auto_minimize_forms' );
function auto_minimize_forms( $form ) {
  $form = str_replace( array( "rn", "r", "n", "t", '    ' ), '', $form );
  return $form;
}