HTML Help provides many of the features of WinHelp, and adds the following features:
- Support for HTML.
- Support for Microsoft ActiveX and scripting.
- Support for HTML image formats (.jpg, .gif, .png).
- Capability to jump from a Help topic to a site on the Internet.
- Capability to view the HTML code for a Help topic.
HTML Help is created with Microsoft HTML Help Workshop, which is included with Visual FoxPro. HTML Help Workshop provides a complete authoring system for HTML Help, and includes backwards compatibility that allows you to easily create HTML Help files from existing WinHelp projects. To create HTML Help files for your application, consult the online Help for the HTML Help Workshop.
A sample HTML Help project, part of the Solutions sample, is included in a .zip file, Solnhlp.zip, located in the Tools\XSource directory of HOME(0). It includes the following files:
|Solution.chm||Compiled Help file.|
|Solution.hhp||Project file - a text file that brings together all the elements of a help project and contains information about how a compiled help file will appear.|
|Solution.hhk||Index file - contains the index entries (keywords) for your index.|
|Solution.hhc||Table of Contents file.|
|Solution.ali||Alias file for context-sensitive Help support. Maps product Ids to Help topics.|
|Solution.hh||Header file for context-sensitive Help support. Includes product Ids.|
|Solution.chi||Index file used when you ship .chm files that are likely to remain on a CD-ROM, as in the case of the MSDN Library. The .chi file allows certain navigation information to be installed locally on a hard disk for quick access, while the main content lives on the CD-ROM. A .chi file should not be used in a non-CD-ROM scenario. When a .chi file is not used, all the information that would be in it remains in the .chm itself.|
|MSDN_ie3.css||Cascading style sheet.|
|MSDN_ie4.css||Cascading style sheet.|
|FileName.htm||Source content files.|
|FileName.gif||Source graphics files.|
Planning Access to Online HTML Help
In addition to creating an HTML Help file that contains useful information, you need to provide a means for users of your application to access Help. There are three ways to deliver Help:
- A Help menu — a menu that appears on the main menu bar of your application.
- Context-sensitive Help — Help that appears when a user presses F1 (or another key that you specify) while a particular object, control, or menu option is selected.
- "What's This?" Help — Help that appears when a user calls for help on a particular object or control.
Implementing HTML Help is similar to implementing WinHelp. The following sections describe how you can implement HTML Help for your application.
Planning a Help Menu
A Help menu typically contains commands that provide access to the topics in your Help system. It is strongly recommended to have a single command on your Help menu that opens your HTML Help system. Beyond that, you can place additional commands on the Help menu that provide system information, or copyright and version information about your application.