Creating custom forms for modal forms

If you want to create custom forms (custom window sizes) for modal forms, there is a hook in module that will let you define them. By default you have small, medium, large. This way you can create your own.

Use modal_forms_js_settings hook alter and just add data to $js_settings array

 
function mymodul_modal_forms_js_settings_alter(&$js_settings){

 $js_settings['modal-popup-login'] = array(
      'modalSize' => array(
        'type' => variable_get('modal_forms_popup_extra_type', 'fixed'),
        'width' => floatval(variable_get('modal_forms_popup_extra_width', 400)),
        'height' => floatval(variable_get('modal_forms_popup_extra_height', 400)),
      ),
      'modalOptions' => array(
        'opacity' => floatval(variable_get('modal_forms_opacity', 0.83)),
        'background' => variable_get('modal_forms_background_color', '#000'),
      ),
      'animation' => 'fadeIn',
      'modalTheme' => 'ModalFormsPopup',
      'throbber' => $throbber,
      'closeText' => t('Close'),
    );
}

later just add that class to link you are creating for making modal form pop up and you will have that exact config running. For example I override the size of the login popup

(function ($) {

Drupal.behaviors.initModalFormsLogin = {
  attach: function (context, settings) {
    $("a[href*='/user/login'], a[href*='?q=user/login']", context).once('init-modal-forms-login', function () {
      this.href = this.href.replace(/user\/login/,'modal_forms/nojs/login');
    }).addClass('ctools-use-modal ctools-modal-modal-popup-login');
  }
};

})(jQuery);