Autoload

SYNOPSIS

subroutine_name_or_ITL_code...

DESCRIPTION

Specify actions (in form of Perl subroutines or ITL tags) that are to be invoked automatically, on every page access. This step is performed before any page parsing occurs, and before the action or page is even determined.

The directive can be set to the name of a subroutine (Sub or GlobalSub), or to a string containing ITL tags. The return value from the code run is discarded.

DIRECTIVE TYPE AND DEFAULT VALUE

Catalog directive

EXAMPLES

Example: Simple Autoload example

Put the following in interchange.cfg:

GlobalSub <<EOR
  sub simple_gsub {
    open OUT, "> /tmp/out";
    print OUT scalar localtime, "\n";
    close OUT;
  }
EOR

Put the following in catalog.cfg:

Autoload simple_gsub

Now, at each page visit, the file /tmp/out will contain the access time. This example is pretty useless and does not convey good programming practice (the file opening part), but it does show a practical, stand-alone example.

Example: Redirect page accesses

Let's say that a new page visit is "triggered" as a result of users submitting a HTML form. At that point, mv_nextpage contains the name of the page to display next, of course.

The following would redirect all accesses from directory public/ to directory private/:

Autoload  [perl] $CGI->{mv_nextpage} =~ s:^public/:private/:; [/perl]

Example: Temporary change of configuration directives

As you might know, on each page access, all catalog configuration directives (global and catalog) are "re-instantiated", and valid for the current page. This particularly convenient feature allows us to change (modify, add or delete) configuration directives as we see fit on a per-page basis, without worrying about them being persistent, and consequently, even without the need to re-set them back to original values.

The following example (put in catalog.cfg) displays a different flypage for Opera web browsers:

Autoload <<EOA
[perl] 
  if ($Session->{browser} =~ /opera/i) {
    $Config->{Special}->{flypage} = 'opera_flypage';
  }
[/perl]
EOA

NOTES

AVAILABILITY

Autoload is available in Interchange versions:

4.6.0-5.9.0 (git-head)

SOURCE

Interchange 5.9.0:

Source: lib/Vend/Config.pm
Line 596

['Autoload',     'routine_array',   ''],

Source: lib/Vend/Config.pm
Line 3802 (context shows lines 3802-3836)

sub parse_routine_array {
my($item,$settings) = @_;

return '' unless $settings;

my $c;
if(defined $C) {
  $c = $C->{$item};
}
else {
  no strict 'refs';
  $c = ${"Global::$item"};
}

my @mac;

if($settings =~ /^[-\s\w,]+$/) {
  @mac = grep /\S/, split /[\s,]+/, $settings;
}
else {
  push @mac, $settings;
}

if(ref($c) eq 'ARRAY') {
  push @$c, @mac;
}
elsif($c) {
  $c = [$c, @mac];
}
else {
  $c = scalar(@mac) > 1 ? [ @mac ] : $mac[0];
}

return $c;
}

AUTHORS

Interchange Development Group

Name