Offline Application

Basics

An offline web application is a list of URLs — HTML, CSS, JavaScript, images, or any other kind of resource. The home page of the offline web application points to this list, called a manifest file, which is just a text file located elsewhere on the web server. A web browser that implements HTML5 offline applications will read the list of URLs from the manifest file, download the resources, cache them locally, and automatically keep the local copies up to date as they change. When the time comes that you try to access the web application without a network connection, your web browser will automatically switch over to the local copies instead.

Manifest file
An offline web application revolves around a cache manifest file. What’s a manifest file? It’s a list of all of the resources that your web application might need to access while it’s disconnected from the network. In order to bootstrap the process of downloading and caching these resources, you need to point to the manifest file, using a manifest attribute on your element.




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Your cache manifest file can be located anywhere on your web server, but it must be served with the content type text/cache-manifest.