Data Storage and Cookies

This section contains overviews and tutorials for data storage and cookies.

Data Storage and Cookies

About DHTML Data Transfer

As of Microsoft Internet Explorer 5, you have access to an extensive data transfer implementation. For Windows Internet Explorer, data transfer involves writing information to and reading it from the clipboard through a data transfer object. The information transferred includes both the data format and the data itself.

Introduction to DOM Storage

The Web Storage API includes two related mechanisms for persisting client-side data in a secure manner using the Document Object Model (DOM), sessionStorage and localStorage. These objects were introduced in Internet Explorer 8.

Persistence

Introduction to Persistence

Persistence enables authors to specify an object to persist on the client during the current and later sessions using Dynamic HTML (DHTML) behaviors. Persistence allows Internet Explorer 5 and later to retain Web page information, styles, variables, and state.

Persisting Collapsible Table of Contents State

Web pages that employ a collapsible table of contents tend to share a single problem: when a user leaves the page, the table of contents reverts to its original state. For anyone trying to navigate through these nested references, it is frustrating to leave the page and return, only to have to wade through the table of contents again. Persistence behavior provides a solution to this problem.

Persisting Custom and Dynamic Styles

Dynamic and custom styles selected at run time by the user can be persisted when the page is saved as a favorite using the saveFavorite behavior.

Persisting Form Data

Using HTML to design forms comes with some drawbacks, namely the need for a server or client-side script to process the form data. The saveSnapshot behavior can be used to save a Web page and persist the form data directly within the page itself. This allows a larger audience to use Web forms for day-to-day activities without needing a special script to process and deliver the information.

Persisting Session Information

Session information is usually recorded for sites that use multiple pages to accomplish a task, such as virtual shopping carts and advanced search engines. Pages that employ these variables and files can easily swell to a very large size while they juggle delivering a Web page and processing the surrounding scripts. Persistence allows most of this information to be stored on the client, thus decreasing download time and the performance hit to the server's processor(s).