HelpIndex Advanced Topics

Last modified: 21 February 1997.
Page Contents
User Speed Up
Other Information
Bug List
Version history

User Speed Up

This technique may be superceded soon if we adopt Marimba Castanet technology. This allows the applet to be downloaded and kept up to date.
Anyone who visits a site with HelpIndex will have to wait for all the necessary classes to load from the server. Currently the version 2 class files are over 80kB, ie not too big.

However if a user is a regular visitor and wishes to speed up class loading, then they can download all the HelpIndex classes on their local hard disk.

This process is not straight forward and new versions are not used, so this technique is not recommended.

They need to download HelpIndex.zip and unzip the files in a new directory. They need to set up an environment variable called CLASSPATH and add the new directory name to it. We use an unzip program called Info-Zip

Alternatively, you can rename HelpIndex.zip to classes.zip and add the full pathname of classes.zip to CLASSPATH.

The one drawback of this approach is that the version of HelpIndex on their local disk takes precedence over the version on a server. So if the server has a later version then it will not be used.


Other Information

HelpIndex is best used with PC Netscape Navigator 3.0 as it runs Java slightly better than IE3.0 and N2.0. Delve into our Java notes and comments for the reasons.

HelpIndex Index File Format

The routines getAppletInfo() and getParameterInfo() are implemented.

Java Console

If the mode parameter has incorrect entries or an index<N> parameter has incorrect options then an error message is written to the Java Console (Navigator) or the Java log file (Internet Explorer).

Similarly, any invalid lines in the index file result in a warning message being written to the Java Console/log file.

In Windows Netscape Navigator 3.0, you should select Options+Show Java Console to see these messages.
For Windows Internet Explorer 3.0, in View+Options+Advanced tab, "Enable Java Logging" must be turned on to store these messages. In NT 4.0 the messages appear by default in C:\WINNT\Java\JavaLog.txt.


Bug List

Major: Medium: Not major: Major, but unfixable:

Version history

See the version history of MakeHelpIndex and the Help Index File Format.
2.0.0 21 February 1997 Has a Contents "tree" of the web site.
Has a "card" arrangement with Contents, Index, Select and About tabs.
The Select tab allows new index files and languages to be loaded.
Displays a "Loading" message.
Revised language file format.
1.7.1 13 January 1997 Allows two HelpIndex applets on one page to read same index file correctly
1.7.0 18 December 1996 Uses language file
Mode parameter allows high form arrangement.
IndexLines parameter added
Double-clicking page shows URL
Index file fields can be empty, ie need not contain a space
fieldbgcolor parameter added
1.6.0 6 December 1996 Limited index capacity.
Reads format 1.2 index files (and earlier)
Individual index's Target field takes precedence over default frame.
1.5.4 14 November 1996 Floating window sized better.
Form layout improved marginally.
1.5.3 22 October 1996 Ensures that / character at end of Base URL.
The query parameter is a C style string so you can specify spaces at its end.
1.5.2 16 October 1996 Format code 1.1 introduced.
IE3.0 window displays status text better
1.5.1 15 October 1996 Each applet instance has its own index file
1.5.0 14 October 1996 Separate floating window mode introduced.
Format code 1.0 introduced
1.2.5 Escape clears to initial query. F1 displays status bar help.
1.2.4 font parameter added, using PHDUtils version 1.1
1.2.3 No abort if form cannot be laid out (GridBagLayout array exception caught)
1.2.2 query parameter added
1.2.1 Index.class renamed to HlpIndex.class. Colours work. Other unnoticeables. Works when revisited by N3.0.
1.2 Has a separate thread to (a) read the index file and (b) look up a query. The query lookup is stopped and started again whenever a new key arrives.
1.1.5 Added minquerylength parameter.
1.1.4 Clears selected URL if query not found.
1.1.3 Copes with amended format code 0, ie characters after Index Item title URL short-cut.

HelpIndex    PHD