While Javascript form validation shouldn't be your only form of defense with regards to user input, it definitely improves the usability and efficiency of a site. It can also give your site a web 2.0 feel - which users seem to love.

Javascript Validation in Magento

By default Magento uses a file called form.js (js/varien/form.js) to provide abstract Javascript functions for forms. The most useful application of this class - in my opinion - is the form validation. To achieve this validation, form.js uses the Validation class which is part of the Prototype Javascript library. It works by checking form inputs for certain class names. Each class name tells the validator to perform certain checks on the value inside the input.

Custom Form Validation

Adding Javascript validation to your own forms is extremely simple. First, you need to create a Form (form.js) object to represent your form.

The first parameter, in this case formId, is the ID of your form. The second parameter defines whether or not the first input field in the form should steal the cursor focus. If set to true, the cursor will automatically be moved into the first input field and any user input will be entered into this field. You can disable this functionality by setting the second parameter to false.

Now that you have created a Javascript object to represent your form you need to add some validation rules to your form inputs.

Notice the classes 'required-entry' and 'validate-email'? These both tell the classes to apply certain validation rules on the input fields. If any of the validation checks fail, the form will not be submitted and the user will be alerted to the errors.

Magento Javascript Validation Classes

There are many more validation classes you can assign and I list them here as a reference. For more information on this please use Google, experiment with the code or contact me via my email or the contact form.

validate-select

Please select an option

required-entry

This is a required field

validate-number

Please enter a valid number in this field

validate-digits

Please use numbers only in this field. please avoid spaces or other characters such as dots or commas

validate-alpha

Please use letters only (a-z or A-Z) in this field.

validate-code

Please use only letters (a-z), numbers (0-9) or underscore(_) in this field, first character should be a letter.

validate-alphanum

Please use only letters (a-z or A-Z) or numbers (0-9) only in this field. No spaces or other characters are allowed

validate-street

Please use only letters (a-z or A-Z) or numbers (0-9) or spaces and # only in this field

validate-phoneStrict

Please enter a valid phone number. For example (123) 456-7890 or 123-456-7890

validate-phoneLax

Please enter a valid phone number. For example (123) 456-7890 or 123-456-7890

validate-fax

Please enter a valid fax number. For example (123) 456-7890 or 123-456-7890

validate-date

Please enter a valid date

validate-email

Please enter a valid email address. For example johndoe@domain.com.

validate-emailSender

Please use only letters (a-z or A-Z), numbers (0-9) , underscore(_) or spaces in this field.

validate-password

Please enter 6 or more characters. Leading or trailing spaces will be ignored

validate-admin-password

Please enter 7 or more characters. Password should contain both numeric and alphabetic characters

validate-cpassword

Please make sure your passwords match

validate-url

Please enter a valid URL. http:// is required

validate-clean-url

Please enter a valid URL. For example http://www.example.com or www.example.com

validate-identifier

Please enter a valid Identifier. For example example-page, example-page.html or anotherlevel/example-page

validate-xml-identifier

Please enter a valid XML-identifier. For example something_1, block5, id-4

validate-ssn

Please enter a valid social security number. For example 123-45-6789

validate-zip

Please enter a valid zip code. For example 90602 or 90602-1234

validate-zip-international

Please enter a valid zip code

validate-date-au

Please use this date format: dd/mm/yyyy. For example 17/03/2006 for the 17th of March, 2006

validate-currency-dollar

Please enter a valid $ amount. For example $100.00

validate-one-required

Please select one of the above options.

validate-one-required-by-name

Please select one of the options.

validate-not-negative-number

Please enter a valid number in this field

validate-state

Please select State/Province

validate-new-password

Please enter 6 or more characters. Leading or trailing spaces will be ignored

validate-greater-than-zero

Please enter a number greater than 0 in this field

validate-zero-or-greater

Please enter a number 0 or greater in this field

validate-cc-number

Please enter a valid credit card number.

validate-cc-type

Credit card number doesn't match credit card type

validate-cc-type-select

Card type doesn't match credit card number

validate-cc-exp

Incorrect credit card expiration date

validate-cc-cvn

Please enter a valid credit card verification number.

validate-data

Please use only letters (a-z or A-Z), numbers (0-9) or underscore(_) in this field, first character should be a letter.

validate-css-length

Please input a valid CSS-length. For example 100px or 77pt or 20em or .5ex or 50%

validate-length

Maximum length exceeded