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##============================================================= -*-Perl-*-
#
# Template::Document
#
# DESCRIPTION
# Module defining a class of objects which encapsulate compiled
# templates, storing additional block definitions and metadata
# as well as the compiled Perl sub-routine representing the main
# template content.
#
# AUTHOR
# Andy Wardley <abw@wardley.org>
#
# COPYRIGHT
# Copyright (C) 1996-2007 Andy Wardley. All Rights Reserved.
#
# This module is free software; you can redistribute it and/or
# modify it under the same terms as Perl itself.
#
#============================================================================
package Template::Document;
use strict;
use warnings;
use base 'Template::Base';
use Template::Constants;
our $VERSION = 2.79;
our $DEBUG = 0 unless defined $DEBUG;
our $ERROR = '';
our ($COMPERR, $AUTOLOAD, $UNICODE);
BEGIN {
# UNICODE is supported in versions of Perl from 5.008 onwards
if ($UNICODE = $] > 5.007 ? 1 : 0) {
if ($] > 5.008) {
# utf8::is_utf8() available from Perl 5.8.1 onwards
*is_utf8 = \&utf8::is_utf8;
}
elsif ($] == 5.008) {
# use Encode::is_utf8() for Perl 5.8.0
require Encode;
*is_utf8 = \&Encode::is_utf8;
}
}
}
#========================================================================
# ----- PUBLIC METHODS -----
#========================================================================
#------------------------------------------------------------------------
# new(\%document)
#
# Creates a new self-contained Template::Document object which
# encapsulates a compiled Perl sub-routine, $block, any additional
# BLOCKs defined within the document ($defblocks, also Perl sub-routines)
# and additional $metadata about the document.
#------------------------------------------------------------------------
sub new {
my ($class, $doc) = @_;
my ($block, $defblocks, $variables, $metadata) = @$doc{ qw( BLOCK DEFBLOCKS VARIABLES METADATA ) };
$defblocks ||= { };
$metadata ||= { };
# evaluate Perl code in $block to create sub-routine reference if necessary
unless (ref $block) {
local $SIG{__WARN__} = \&catch_warnings;
$COMPERR = '';
# DON'T LOOK NOW! - blindly untainting can make you go blind!
$block =~ /(.*)/s;
$block = $1;
$block = eval $block;
return $class->error($@)
unless defined $block;
}
# same for any additional BLOCK definitions
@$defblocks{ keys %$defblocks } =
# MORE BLIND UNTAINTING - turn away if you're squeamish
map {
ref($_)
? $_
: ( /(.*)/s && eval($1) or return $class->error($@) )
} values %$defblocks;
bless {
%$metadata,
_BLOCK => $block,
_DEFBLOCKS => $defblocks,
_VARIABLES => $variables,
_HOT => 0,
}, $class;
}
#------------------------------------------------------------------------
# block()
#
# Returns a reference to the internal sub-routine reference, _BLOCK,
# that constitutes the main document template.
#------------------------------------------------------------------------
sub block {
return $_[0]->{ _BLOCK };
}
#------------------------------------------------------------------------
# blocks()
#
# Returns a reference to a hash array containing any BLOCK definitions
# from the template. The hash keys are the BLOCK name and the values
# are references to Template::Document objects. Returns 0 (# an empty hash)
# if no blocks are defined.
#------------------------------------------------------------------------
sub blocks {
return $_[0]->{ _DEFBLOCKS };
}
#-----------------------------------------------------------------------
# variables()
#
# Returns a reference to a hash of variables used in the template.
# This requires the TRACE_VARS option to be enabled.
#-----------------------------------------------------------------------
sub variables {
return $_[0]->{ _VARIABLES };
}
#------------------------------------------------------------------------
# process($context)
#
# Process the document in a particular context. Checks for recursion,
# registers the document with the context via visit(), processes itself,
# and then unwinds with a large gin and tonic.
#------------------------------------------------------------------------
sub process {
my ($self, $context) = @_;
my $defblocks = $self->{ _DEFBLOCKS };
my $output;
# check we're not already visiting this template
return $context->throw(Template::Constants::ERROR_FILE,
"recursion into '$self->{ name }'")
if $self->{ _HOT } && ! $context->{ RECURSION }; ## RETURN ##
$context->visit($self, $defblocks);
$self->{ _HOT } = 1;
eval {
my $block = $self->{ _BLOCK };
$output = &$block($context);
};
$self->{ _HOT } = 0;
$context->leave();
die $context->catch($@)
if $@;
return $output;
}
#------------------------------------------------------------------------
# AUTOLOAD
#
# Provides pseudo-methods for read-only access to various internal
# members.
#------------------------------------------------------------------------
sub AUTOLOAD {
my $self = shift;
my $method = $AUTOLOAD;
$method =~ s/.*:://;
return if $method eq 'DESTROY';
# my ($pkg, $file, $line) = caller();
# print STDERR "called $self->AUTOLOAD($method) from $file line $line\n";
return $self->{ $method };
}
#========================================================================
# ----- PRIVATE METHODS -----
#========================================================================
#------------------------------------------------------------------------
# _dump()
#
# Debug method which returns a string representing the internal state
# of the object.
#------------------------------------------------------------------------
sub _dump {
my $self = shift;
my $dblks;
my $output = "$self : $self->{ name }\n";
$output .= "BLOCK: $self->{ _BLOCK }\nDEFBLOCKS:\n";
if ($dblks = $self->{ _DEFBLOCKS }) {
foreach my $b (keys %$dblks) {
$output .= " $b: $dblks->{ $b }\n";
}
}
return $output;
}
#========================================================================
# ----- CLASS METHODS -----
#========================================================================
#------------------------------------------------------------------------
# as_perl($content)
#
# This method expects a reference to a hash passed as the first argument
# containing 3 items:
# METADATA # a hash of template metadata
# BLOCK # string containing Perl sub definition for main block
# DEFBLOCKS # hash containing further subs for addional BLOCK defs
# It returns a string containing Perl code which, when evaluated and
# executed, will instantiate a new Template::Document object with the
# above data. On error, it returns undef with an appropriate error
# message set in $ERROR.
#------------------------------------------------------------------------
sub as_perl {
my ($class, $content) = @_;
my ($block, $defblocks, $metadata) = @$content{ qw( BLOCK DEFBLOCKS METADATA ) };
$block =~ s/\s+$//;
$defblocks = join('', map {
my $code = $defblocks->{ $_ };
$code =~ s/\s*$//;
" '$_' => $code,\n";
} keys %$defblocks);
$defblocks =~ s/\s+$//;
$metadata = join('', map {
my $x = $metadata->{ $_ };
$x =~ s/(['\\])/\\$1/g;
" '$_' => '$x',\n";
} keys %$metadata);
$metadata =~ s/\s+$//;
return <<EOF
#------------------------------------------------------------------------
# Compiled template generated by the Template Toolkit version $Template::VERSION
#------------------------------------------------------------------------
$class->new({
METADATA => {
$metadata
},
BLOCK => $block,
DEFBLOCKS => {
$defblocks
},
});
EOF
}
#------------------------------------------------------------------------
# write_perl_file($filename, \%content)
#
# This method calls as_perl() to generate the Perl code to represent a
# compiled template with the content passed as the second argument.
# It then writes this to the file denoted by the first argument.
#
# Returns 1 on success. On error, sets the $ERROR package variable
# to contain an error message and returns undef.
#------------------------------------------------------------------------
sub write_perl_file {
my ($class, $file, $content) = @_;
my ($fh, $tmpfile);
return $class->error("invalid filename: $file")
unless $file =~ /^(.+)$/s;
eval {
require File::Temp;
require File::Basename;
($fh, $tmpfile) = File::Temp::tempfile(
DIR => File::Basename::dirname($file)
);
my $perlcode = $class->as_perl($content) || die $!;
if ($UNICODE && is_utf8($perlcode)) {
$perlcode = "use utf8;\n\n$perlcode";
binmode $fh, ":utf8";
}
print $fh $perlcode;
close($fh);
};
return $class->error($@) if $@;
return rename($tmpfile, $file)
|| $class->error($!);
}
#------------------------------------------------------------------------
# catch_warnings($msg)
#
# Installed as
#------------------------------------------------------------------------
sub catch_warnings {
$COMPERR .= join('', @_);
}
1;
__END__
=head1 NAME
Template::Document - Compiled template document object
=head1 SYNOPSIS
use Template::Document;
$doc = Template::Document->new({
BLOCK => sub { # some perl code; return $some_text },
DEFBLOCKS => {
header => sub { # more perl code; return $some_text },
footer => sub { # blah blah blah; return $some_text },
},
METADATA => {
author => 'Andy Wardley',
version => 3.14,
}
}) || die $Template::Document::ERROR;
print $doc->process($context);
=head1 DESCRIPTION
This module defines an object class whose instances represent compiled
template documents. The L<Template::Parser> module creates a
C<Template::Document> instance to encapsulate a template as it is compiled
into Perl code.
The constructor method, L<new()>, expects a reference to a hash array
containing the C<BLOCK>, C<DEFBLOCKS> and C<METADATA> items.
The C<BLOCK> item should contain a reference to a Perl subroutine or a textual
representation of Perl code, as generated by the L<Template::Parser> module.
This is then evaluated into a subroutine reference using C<eval()>.
The C<DEFLOCKS> item should reference a hash array containing further named
C<BLOCK>s which may be defined in the template. The keys represent C<BLOCK>
names and the values should be subroutine references or text strings of Perl
code as per the main C<BLOCK> item.
The C<METADATA> item should reference a hash array of metadata items relevant
to the document.
The L<process()> method can then be called on the instantiated
C<Template::Document> object, passing a reference to a L<Template::Context>
object as the first parameter. This will install any locally defined blocks
(C<DEFBLOCKS>) in the C<BLOCKS> cache in the context (via a call to
L<visit()|Template::Context#visit()>) so that they may be subsequently
resolved by the context. The main C<BLOCK> subroutine is then executed,
passing the context reference on as a parameter. The text returned from the
template subroutine is then returned by the L<process()> method, after calling
the context L<leave()|Template::Context#leave()> method to permit cleanup and
de-registration of named C<BLOCKS> previously installed.
An C<AUTOLOAD> method provides access to the C<METADATA> items for the
document. The L<Template::Service> module installs a reference to the main
C<Template::Document> object in the stash as the C<template> variable. This allows
metadata items to be accessed from within templates, including C<PRE_PROCESS>
templates.
header:
<html>
<head>
<title>[% template.title %]
</head>
...
C<Template::Document> objects are usually created by the L<Template::Parser>
but can be manually instantiated or sub-classed to provide custom
template components.
=head1 METHODS
=head2 new(\%config)
Constructor method which accept a reference to a hash array containing the
structure as shown in this example:
$doc = Template::Document->new({
BLOCK => sub { # some perl code; return $some_text },
DEFBLOCKS => {
header => sub { # more perl code; return $some_text },
footer => sub { # blah blah blah; return $some_text },
},
METADATA => {
author => 'Andy Wardley',
version => 3.14,
}
}) || die $Template::Document::ERROR;
C<BLOCK> and C<DEFBLOCKS> items may be expressed as references to Perl subroutines
or as text strings containing Perl subroutine definitions, as is generated
by the L<Template::Parser> module. These are evaluated into subroutine references
using C<eval()>.
Returns a new C<Template::Document> object or C<undef> on error. The
L<error()|Template::Base#error()> class method can be called, or the C<$ERROR>
package variable inspected to retrieve the relevant error message.
=head2 process($context)
Main processing routine for the compiled template document. A reference to a
L<Template::Context> object should be passed as the first parameter. The
method installs any locally defined blocks via a call to the context
L<visit()|Template::Context#visit()> method, processes its own template,
(passing the context reference as a parameter) and then calls
L<leave()|Template::Context#leave()> in the context to allow cleanup.
print $doc->process($context);
Returns a text string representing the generated output for the template.
Errors are thrown via C<die()>.
=head2 block()
Returns a reference to the main C<BLOCK> subroutine.
=head2 blocks()
Returns a reference to the hash array of named C<DEFBLOCKS> subroutines.
=head2 variables()
Returns a reference to a hash of variables used in the template.
This requires the L<TRACE_VARS|Template::Manual::Config#TRACE_VARS>
option to be enabled.
=head2 AUTOLOAD
An autoload method returns C<METADATA> items.
print $doc->author();
=head1 CLASS METHODS
These methods are used internally.
=head2 as_perl($content)
This method generate a Perl representation of the template.
my $perl = Template::Document->as_perl({
BLOCK => $main_block,
DEFBLOCKS => {
foo => $foo_block,
bar => $bar_block,
},
METADATA => {
name => 'my_template',
}
});
=head2 write_perl_file(\%config)
This method is used to write compiled Perl templates to disk. If the
C<COMPILE_EXT> option (to indicate a file extension for saving compiled
templates) then the L<Template::Parser> module calls this subroutine before
calling the L<new()> constructor. At this stage, the parser has a
representation of the template as text strings containing Perl code. We can
write that to a file, enclosed in a small wrapper which will allow us to
subsequently C<require()> the file and have Perl parse and compile it into a
C<Template::Document>. Thus we have persistence of compiled templates.
=head1 INTERNAL FUNCTIONS
=head2 catch_warnings()
This is a simple handler used to catch any errors that arise when the
compiled Perl template is first evaluated (that is, evaluated by Perl to
create a template subroutine at compile, rather than the template being
processed at runtime).
=head2 is_utf8()
This is mapped to C<utf8::is_utf8> for versions of Perl that have it (> 5.008)
or to C<Encode::is_utf8> for Perl 5.008. Earlier versions of Perl are not
supported.
=head1 AUTHOR
Andy Wardley E<lt>abw@wardley.orgE<gt> L<http://wardley.org/>
=head1 COPYRIGHT
Copyright (C) 1996-2013 Andy Wardley. All Rights Reserved.
This module is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.
=head1 SEE ALSO
L<Template>, L<Template::Parser>
=cut
# Local Variables:
# mode: perl
# perl-indent-level: 4
# indent-tabs-mode: nil
# End:
#
# vim: expandtab shiftwidth=4:
Zerion Mini Shell 1.0