Jquery Validation

jquery_validaiton_common.js

$("form.validate:not([novalidate])").each(function() {
    formValidations = {
      errorElement: "span",
      errorClass: "errorField",
      rules: {},
      messages: {}
    };
    $(this).find("input, select, textarea").each(function() {
      if ($(this).data("rules") !== undefined) {
        formValidations['rules'][$(this).attr('name')] = $(this).data("rules");
      }
      if ($(this).data("messages") !== undefined) {
        formValidations['messages'][$(this).attr('name')] = $(this).data("messages");
      }
    });
    $(this).validate(formValidations);
  });

sample_common.html.erb

<%= text_field_tag "city", '', class: "form-control", data: {rules: {required: true, minlength: 2, lettersonly: true}, messages: {required: "Please enter your city"}} %>
<%= text_field_tag "zip", '', class: "form-control", data: {rules: {required: true, minlength: 4, maxlength: 8, digits: true}, messages: {required: "Please enter zip number", digits: "Please enter number only", minlength: "Short zip number"}}, maxlength: 8 %>

validate.js.coffee

#https://github.com/jzaefferer/jquery-validation

//= require jquery.validate.min

root = exports ? this
$(document).ready ->
  s = undefined

  UserAuthentication =
    settings:
      userLoginForm: $(".userLoginForm")

    init: ->
      s = @settings
      @bindUIActions()

    bindUIActions: ->
      s.userLoginForm.validate
        errorElement: "span"
        errorClass: "errorSpan"
        rules:
          "user[email]": "required"
          "user[password]": "required"
        messages:
          "user[email]":
            required: "Please enter email"
          "user[password]":
            required: "Please enter password"

  UserAuthentication.init()