Rails-UJS

Rails-ujs was formerly JQuery-ujs but the JQuery dependency was removed hence the name change.

form_with

Rails 5.1 added form_with form helper method that provides capabilities of form_for and form_tag. Rails unified form_for and form_tag that provide similar interfaces to generate forms with form_with helper.

• form_for was being used to generate form for a new/existing model object.
• form_tag was used to create form without a model object by passing a URL to submit the form.

Now we can use form_with for both model and non-model based forms.

• submit via AJAX is the default

If your application uses rails-ujs, the form will be submitted via ajax, and it listens on following events.

• ajax:success : This event is called when Ajax response is success.

• ajax:error : This event is called when Ajax response is failure.

Event can be binded on form as given below.

$(document).on('ajax:success', '#new_user', function(e) {
  console.log('form_with: successfully submitted form via ajax');
});
         
$(document).on('ajax:error', '#new_user', function(e) {
  console.log('form_with: error submitting form via ajax');
});