尝试为 Haml 创建 Template::Plugin::Filter

Question

我正在尝试创建一个将 Text::Haml 集成到模板工具包中的 cpan 模块。我认为 Haml 是一种有趣的模板语言，但相当有限，它不支持循环或条件，更不用说更高级的东西了。但我似乎无法让夏娃有一个非常简单的版本来工作。以下是一些测试脚本，可确保我的逻辑正常工作。

这是我使用 Template:: 的过滤器模块的尝试Plugin::Filter 文档

use strict;
use warnings;
package Template::Plugin::Haml;

use Template::Plugin::Filter;

use parent 'Template::Plugin::Filter';

sub filter {
    my ( $self, $text ) = @_;

# thes aren't actually the problem
#   my $haml = Text::Haml->new;
#   my $html = $haml->render($text);
#   return $html;

    return $text;
}
1;

和一些使用它的代码

#!/usr/bin/perl
# test0.pl
use strict;
use warnings;

use Template;

my $tt = Template->new;

my $vars = {};
my $output = \do{my $i};

$tt->process(\*DATA, $vars, $output);

print $$output;
__DATA__
[% USE Haml %]
[% FILTER Haml %]
#profile
[% END %]

，但我收到此警告 Use of uninitialized value in print at test0.pl line 15,第 1 行。

我知道这个错误意味着什么...但我不确定为什么过滤器会导致这个错误。任何帮助将不胜感激

以下是我的逻辑其他部分工作的一些测试脚本，这样我们就不会查看错误的代码来解决问题。否则它们对于问题来说并不是真正必要的

这显示了如何使用 Template::Toolkit

#!/usr/bin/perl
# test1.pl - show how to use tt
use strict;
use warnings;

use Template;

my $tt = Template->new;

my $vars = {};
my $output = \do{my $i};

$tt->process(\*DATA, $vars, $output);

print $$output; # #profile
__DATA__
#profile

这向我们展示了如何使用 Text::Haml

#!/usr/bin/perl
# test2.pl
use 5.010;
use strict;
use warnings;

use Text::Haml;

my $text = '#profile';
my $haml = Text::Haml->new;
my $html = $haml->render($text);
say $html; # <div id='profile'></div>

UPDATE 1

我已经尝试过这个（这几乎与markdown 插件和一个几乎与 Textile 插件相同的插件）

use strict;
use warnings;
package Template::Plugin::Haml;

use parent 'Template::Plugin::Filter';
use 'Text::Haml';

sub init {
    my $self = shift;
    $self->{_DYNAMIC} = 1;
    $self->install_filter( $self->{_ARGS}->[0] || 'haml');
    $self;
}

sub filter {
    my ( $self, $text, $args, $config ) = @_;

    my $haml = Text::Haml->new;
    return $haml->render($text);
}
1;

更新 2 启用 DEBUG => 的输出'all', 在 TT 初始化时

[Template::Provider] creating cache of unlimited slots for [ . ]
[Template::Service] process(GLOB(0x1719608), HASH(0x16f1650))
[Template::Context] template(GLOB(0x1719608))
[Template::Context] asking providers for [GLOB(0x1719608)] []
[Template::Provider] _load(GLOB(0x1719608), <no alias>)
[Template::Provider] _compile(HASH(0x1a947a0), <no compfile>)
[Template::Parser] compiled main template document block:
sub {
    my $context = shift || die "template sub called without context\n";
    my $stash   = $context->stash;
    my $output  = '';
    my $_tt_error;

    eval { BLOCK: {
#line 1 "input file handle"
$output .=  $context->debugging('msg', { 'line' => '1', 'text' => 'USE Haml', 'file' => 'input file handle' }); ## DEBUG ##
#line 1 "input file handle"
# USE
$stash->set('Haml',
            $context->plugin('Haml'));
#line 2 "input file handle"
$output .=  $context->debugging('msg', { 'line' => '2', 'text' => 'FILTER haml', 'file' => 'input file handle' }); ## DEBUG ##
#line 4 "input file handle"

# FILTER
$output .=  do {
    my $output = '';
    my $_tt_filter = $context->filter('haml')
              || $context->throw($context->error);

$output .=  "#profile";
#line 4 "input file handle"
$output .=  $context->debugging('msg', { 'line' => '4', 'text' => 'END', 'file' => 'input file handle' }); ## DEBUG ##

    &$_tt_filter($output);
};

    } };
    if ($@) {
        $_tt_error = $context->catch($@, \$output);
        die $_tt_error unless $_tt_error->type eq 'return';
    }

    return $output;
}
[Template::Service] PROCESS: Template::Document=HASH(0x1c69ba0)
[Template::Context] process([ Template::Document=HASH(0x1c69ba0) ], <no params>, <unlocalized>)
[Template::Context] template(Template::Document=HASH(0x1c69ba0))
[Template::Context] plugin(Haml, [ ])
[Template::Plugins] fetch(Haml, <no args>, Template::Context=HASH(0x1972040))
[Template::Plugins] loading Template/Plugin/Haml.pm (PLUGIN_BASE)
[Template::Plugins] calling Template::Plugin::Haml->load()
[Template::Plugins] Haml => Template::Plugin::Haml
[Template::Filters] store(haml, ARRAY(0x1c1f4d8))
[Template::Context] filter(haml, [ ]<no alias>)
[Template::Filters] fetch(haml, <no args>, Template::Context=HASH(0x1972040))
Use of uninitialized value in string eq at /usr/share/perl5/vendor_perl/Text/Haml.pm line 452, <DATA> line 1.
Use of uninitialized value in string eq at /usr/share/perl5/vendor_perl/Text/Haml.pm line 452, <DATA> line 1.
Use of uninitialized value in string eq at /usr/share/perl5/vendor_perl/Text/Haml.pm line 452, <DATA> line 1.
Use of uninitialized value in string eq at /usr/share/perl5/vendor_perl/Text/Haml.pm line 452, <DATA> line 1.
Use of uninitialized value in string eq at /usr/share/perl5/vendor_perl/Text/Haml.pm line 452, <DATA> line 1.
Use of uninitialized value in string eq at /usr/share/perl5/vendor_perl/Text/Haml.pm line 452, <DATA> line 1.
Use of uninitialized value in string eq at /usr/share/perl5/vendor_perl/Text/Haml.pm line 452, <DATA> line 1.
Use of uninitialized value in string eq at /usr/share/perl5/vendor_perl/Text/Haml.pm line 452, <DATA> line 1.
Use of uninitialized value in string eq at /usr/share/perl5/vendor_perl/Text/Haml.pm line 452, <DATA> line 1.
Use of uninitialized value in string eq at /usr/share/perl5/vendor_perl/Text/Haml.pm line 452, <DATA> line 1.
Use of uninitialized value in concatenation (.) or string at /usr/share/perl5/vendor_perl/Text/Haml.pm line 674, <DATA> line 1.
Use of uninitialized value in concatenation (.) or string at /usr/share/perl5/vendor_perl/Text/Haml.pm line 683, <DATA> line 1.

## input file handle line 1 : [% USE Haml %] ##

## input file handle line 2 : [% FILTER haml %] ##
<div id='profile'></div>
<>## input file handle line 4 : [% END %] ##</>

Answer 1

以下是 CPAN 最终产品的链接 模板::Plugin::Haml

明白了

use strict;
use warnings;
package Template::Plugin::Haml;

use parent 'Template::Plugin::Filter';
use Text::Haml;

sub init {
    my $self = shift;
    $self->{_DYNAMIC} = 1;
    $self->install_filter( $self->{_ARGS}->[0] || 'haml');
    $self;
}

sub filter {
    my ( $self, $text, $args, $config ) = @_;

    my $haml = Text::Haml->new;
    return $haml->render($text);
}
1;

，test0.pl

#!/usr/bin/perl
# test0.pl
use strict;
use warnings;

use Template;

my $tt = Template->new; #or die $Template::Error, "\n";

my $vars = {};
my $output = \do{my $i};

$tt->process(\*DATA, $vars, $output);

print $output; # \n\n<div id='profile'></div>\n\n
__DATA__
[% USE Haml %]
[% FILTER haml %]
#profile
[% END %]

似乎我引用了 use 'Text::Haml' 并且我需要一些初始化代码。

Answer 2

好吧，我也无法让它工作。

稍微改进测试脚本以消除可能的干扰：

#!/usr/bin/env perl
use strict;
use warnings;
use FindBin qw/$Bin/;
use lib "$Bin/../lib";

use Template;
my $tt = Template->new(
    STRICT => 1,
    PLUGINS => { MyFilter => 'Template::Plugin::Haml'},
    );

$tt->process(\*DATA, {});

__DATA__
Some non haml stuff
[% USE Haml %]
[% FILTER Haml %]
%h1. some haml stuff
[% END %]

当我使用 perl -Ilib t/01-test.t 运行它时（设置了 cpan dist），我没有得到任何输出。但是，如果我在模板中没有 HAML 块的情况下运行此命令，我会得到输出：（

Some non haml stuff

如果我注释掉 Filter HAML 和 END 位，那么我也会得到预期的完整输出）