HTML <input> required attribute and Rails form with remote true.

gistfile1.md

<input> with attribute required

This attribute specifies that the user must fill in a value before submitting a form. It cannot be used when the type attribute is hidden, image, or a button type (submit, reset, or button). The :optional and :required CSS pseudo-classes will be applied to the field as appropriate.

How to show a spinner only when the required validations pass? (Without using any validation plugin, only the required attribute).

Form with a required input

= form_for @person, remote: true do |f|
  = f.text_field, :first_name, required: true
  = f.submit "Create"

Solution

  $(document).on("ajax:beforeSend", "form[data-remote]", function(e){
    /* spinner show logic */
  });