Creating Effective JavaHelp

Assigning Map IDs to Help Topics

The map file associates each help-topic map ID with the URL of a help topic HTML file. The map ID acts as a nickname for the file; the TOC file, index file, and word-search index file all use these nicknames to specify help topics.

In Chapter 1, I showed you how a map file works within a HelpSet. In this section I expand on the map file by explaining how you create, edit, and structure it.

The Map File

Take a look at the map file, Map.jhm, for the Aviation JavaHelp sample. A portion of the contents are shown here:

<?xml version='1.0' encoding='ISO-8859-1' ?>
<!DOCTYPE map
  PUBLIC "-//Sun Microsystems Inc.//DTD JavaHelp Map Version 1.0//EN"
         "http://java.sun.com/products/javahelp/map_1_0.dtd">

<map version="1.0">
  <mapID target="toplevelfolder" url="Images/toplevel.gif"/>
  <mapID target="intro" url="Topics/introduction_to_aviation.htm"/>
  <mapID target="aerodynamics" url="Topics/Aerodynamics/aerodynamics.htm"/>
  <mapID target="drag" url="Topics/Aerodynamics/drag.htm"/>
  <mapID target="lift" url="Topics/Aerodynamics/lift.htm"/>
  <mapID target="thrust" url="Topics/Aerodynamics/thrust.htm"/>
  <mapID target="weight" url="Topics/Aerodynamics/weight.htm"/>
</map>

As in the HelpSet file, the XML declaration (<?xml ...) and the document type definition (<!DOCTYPE ...) are optional. The root element of the map file is named “map,” specified with the <map> and </map> tags. The <map> start-tag includes an optional version attribute, where you can specify the JavaHelp ...