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The previous example is nice, it demonstrates the basic ability to
have website-wide variables set up in base.epl and then
automatically shared by all other files. Leading on from this, we
probably want to split up our files, for both maintainability and
readability. For example, a non-trivial website will probably define
some website-wide constants, perhaps some global variables, and maybe
also have some kind of initialization code which has to be executed
for every page (e.g. setting up a database connection). We could put
all of this in base.epl, but this file would quickly begin to look
really messy. It would be nice to split this stuff out into other
files. For example: /base.epl
<HTML>
[- Execute ('constants.epl')-]
[- Execute ('init.epl')-]
<HEAD>
<TITLE>Some title</TITLE>
</HEAD>
<BODY>
[- Execute ('*') -]
</BODY>
[- Execute ('cleanup.epl') -]
</HTML>/constants.epl
[-
$req = shift;
$req->{bgcolor} = "white";
$req->{webmaster} = "John Smith";
$req->{website_database} = "mydatabase";
-] /init.epl
[-
$req = shift;
# Set up database connection
use DBI;
use CGI qw(:standard);
$dsn = "DBI:mysql:$req->{website_database}";
$req->{dbh} = DBI->connect ($dsn);
-] /cleanup.epl
[-
$req = shift;
# Close down database connection
$req->{dbh}->disconnect();
-] You can see how this would be useful, since every page on your site
now has available a database connection, in $req->{dbh}. Also notice
that we have a cleanup.epl file which is always executed at the
end - this is very useful for cleaning up, shutting down connections
and so on.
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