Is it possible to get user uid in login form submit in DrupalGap?
Try using this hook in your app: http://api.drupalgap.org/7/global.html#hook_services_postprocess

/**
 * Implements hook_services_postprocess().
 */
function my_module_services_postprocess(options, result) {
  if (options.service == 'user' &amp;&amp; options.resource == 'login') {
    drupalgap_goto('user-dashboard/'+ Drupal.user.uid);
  }
}


You may also need to set the action on the form object to null so that DrupalGap core doesn't try to redirect the page to the path indicated by the form's action variable:

/**
 * Implements hook_form_alter().
 */
function my_module_form_alter(form, form_state, form_id) {
  if (form_id == 'user_login_form') {
    form.action = null;
  }
}