Browse Prior Art Database

A Proposed Extension to HTML : Client-Side Image Maps (RFC1980)

IP.com Disclosure Number: IPCOM000004199D
Original Publication Date: 1996-Aug-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 6 page(s) / 12K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

J. Seidman: AUTHOR

Abstract

The markup language known as "HTML/2.0" provides for image maps. Image maps are document elements which allow clicking different areas of an image to reference different network resources, as specified by Uniform Identifier (URIs). The image map capability in HTML/2.0 is limited in several ways, such as the restriction that it only works with documents served via the "HTTP" protocol, and the lack of a viable fallback for users of text-only browsers. This document specifies an extension to the HTML language, referred to as "Client- Side Image Maps," which resolves these limitations.

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 24% of the total text.

Network Working Group J. Seidman

Request for Comments: 1980 Spyglass, Inc.

Category: Informational August 1996

A Proposed Extension to HTML : Client-Side Image Maps

Status of this Memo

This memo provides information for the Internet community. This memo

does not specify an Internet standard of any kind. Distribution of

this memo is unlimited.

Abstract

The markup language known as "HTML/2.0" provides for image maps.

Image maps are document elements which allow clicking different areas

of an image to reference different network resources, as specified by

Uniform Identifier (URIs). The image map capability in HTML/2.0 is

limited in several ways, such as the restriction that it only works

with documents served via the "HTTP" protocol, and the lack of a

viable fallback for users of text-only browsers. This document

specifies an extension to the HTML language, referred to as "Client-

Side Image Maps," which resolves these limitations.

Table of Contents

1. Introduction ............................................... 1

1.1 Purpose ............................................... 1

1.2 Overall Operation ..................................... 2

2. Client-Side Image Map Extension ............................ 2

2.1 Syntax ................................................ 2

2.2 Required Changes to HTML/2.0 DTD ...................... 4

2.3 Backwards Compatibility ............................... 5

2.4 Examples .............................................. 5

3. Security Considerations .................................... 6

4. References ................................................. 6

5. Author's Address ........................................... 7

1. Introduction

1.1 Purpose

Image maps are an important feature of the point-and-click interface

which makes the World Wide Web so popular. The most common use of

image maps is to allow users to access different documents by

clicking different areas in an image.

There are several limitations of the current image map implementation

as it applies to this use. First, it only works over the HTTP

protocol, making it unusable for reading local files or files

accessed via alternate protocols. Second, a server transaction is

required merely to determine where the link is directed. This can

degrade performance noticeably when accessing distant sites. Third,

unlike for normal links, there is no way for a browser to provide

visual feedback to the user showing where a portion of an image map

leads before the user actually clicks it. Lastly, the method for

specifying the active regions of image maps is server-dependent,

compromising portability of documents. This extension to support

client-side image maps addresses these issues.

It is proposed that this extension be included in a future revi...