Adding Progressive Enhancements with jQuery

Progressive enhancement is a term originally coined by Steven Champeon1 in 2003 to describe a webdevelopment technique in which applications are designed to be accessible to any Internet connection and browser using semantic HTML and other technologies that are applied in layers (such as CSS files and JavaScript markup).

For an application to follow the principles of progressive enhancement, it must adhere to the following guidelines:

• Basic content is accessible to all browsers using the simplest, most semantic HTML markup possible.
• All of the basic functionality of the app works in all browsers
• The user’s preferences are respected; this means that the web app doesn’t override browser settings (such as window size).
• Externally linked CSS handles the styling and presentation of the document
• Externally linked JavaScript enhances the user experience, but it remains
  unobtrusive, or non-essential to the application’s operation.

Your application already meets the first four guidelines (it’s not pretty, but the application will work with styles disabled).

So as long as your JavaScript doesn’t create any new functionality that can’t be accessed with JavaScript disabled, you will have successfully created a progressively enhanced web
application.

Origin

• Pro PHP And jQuery. Chapter 7. Page 235.