Required environment variables
==============================

TEACHING_SHARED
This variable specifies the path to the top level of the teaching shared
directory hierarchy, whereever you happen to have put it (e.g., on my
machine this is set to "/Users/nstanger/Documents/Teaching/Shared").

ALL_PAPERS_ROOT
This variable specifies the path to the top level directory for all
papers taught, i.e., the directory that contains the individual paper
directory hierarchies. This assumes that you have all your current paper
directories contained within a single hierarchy. If you don't, you're in
trouble :)  For example, on my machine this is set to
"/Users/nstanger/Documents/Teaching/2005" (which contains directories
INFO212, INFO321, ...).

HANDBOOK_INSTALL_ROOT
This variable specifies the path to the top level directory on the web
server, under which the files for this paper will be installed (that is,
the directory that contains the individual paper directory hierarchies).
Under Windows this would typically point to "\\INFO-NTS-12\DBCourses$"
(but this may require munging depending on how UNC paths are dealt
with). On my machine this is set to "/Volumes/DBCOURSES$", because this
is where the share gets mounted.

XSLT
This variable specifies your preferred XSLT processor. Currently the
valid options are "saxon" for SAXON 6.5.x, "xalan-c" for the C++
implementation of Xalan and "xalan-j" for the Java implementation of
Xalan (weirdly, the latter two have different command line options). For
example, on my machine this is set to "saxon".


Including content files
=======================

To simulate the effect of XML fragment inclusion (which isn't supported
in any software yet), we use ASP like tags in the document files to mark where content
files should be inserted. These tags look something like this:

<@INC[DBMS/Q_What_is_a_DBMS.xml]@>

What the makefile does is run a Perl script to replace each of these
tags with the content of the file specified by the include path (this
path is relative to the root directory of the paper + the section name,
e.g., $(ALL_PAPERS_ROOT)/INFO212/Tutorials).

A problem can arise if one of these tags occurs inside an XML comment, e.g.:

<!--
	<@INC[DBMS/Q_What_is_a_DBMS.xml]@>
-->

This is a problem if the content file Q_What_is_a_DBMS.xml also contains
XML comments. Comments cannot be nested in XML, and the XSLT processor
will complain bitterly. The solution is to "neuter" the include tag, by
changing it in such a way that the Perl script will no longer recognise
it, e.g.:

<!--
	<@IN[DBMS/Q_What_is_a_DBMS.xml]@>
-->

Just remember to change it back when you un-comment the inclusion, or
the XSLT processor will complain about malformed XML tags :)