NAME

Template::Semantic - Use pure XHTML/XML as a template

SYNOPSIS

use Template::Semantic;

print Template::Semantic->process('template.html', {
    'title, h1' => 'Naoki Tomita',
    'ul.urls li' => [
        { 'a' => 'Profile & Contacts', 'a@href' => 'http://e8y.net/', },
        { 'a' => 'Twitter',            'a@href' => 'http://twitter.com/tomita/', },
    ],
});

template.html

<html>
    <head><title>person name</title></head>
    <body>
        <h1>person name</h1>
        <ul class="urls">
            <li><a href="#">his page</a></li>
        </ul>
    </body>
</html>

output:

<html>
    <head><title>Naoki Tomita</title></head>
    <body>
        <h1>Naoki Tomita</h1>
        <ul class="urls">
            <li><a href="http://e8y.net/">Profile &amp; Contacts</a></li>
            <li><a href="http://twitter.com/tomita/">Twitter</a></li>
        </ul>
    </body>
</html>

DESCRIPTION

Template::Semantic is a template engine for XHTML/XML based on XML::LibXML that doesn't use any template syntax. This module takes pure XHTML/XML as a template, and uses XPath or CSS selectors to assign values.

METHODS

$ts = Template::Semantic->new( %options )

Constructs a new Template::Semantic object.

my $ts = Template::Semantic->new(
    ...
);
my $res = $ts->process(...);

If you do not want to change the options from the defaults, you may skip new() and call process() directly:

my $res = Template::Semantic->process(...);

Set %options if you want to change parser options:

  • parser => $your_libxml_parser

    Set if you want to replace XML parser. It should be XML::LibXML based.

    my $ts = Template::Semantic->new(
        parser => My::LibXML->new,
    );
  • (others)

    All other parameters are applied to the XML parser as method calls ($parser->$key($value)). Template::Semantic uses this configuration by default:

    no_newwork => 1  # faster
    recover    => 2  # "no warnings" style

    See "PARSER OPTIONS" in XML::LibXML::Parser for details.

    # "use strict;" style
    my $ts = Template::Semantic->new( recover => 0 );
    
    # "use warnings;" style
    my $ts = Template::Semantic->new( recover => 1 );
$res = $ts->process($filename, \%vars)
$res = $ts->process(\$text, \%vars)
$res = $ts->process(FH, \%vars)

Process a template and return a Template::Semantic::Document object.

The first parameter is the input template, which may take one of several forms:

# filename
my $res = Template::Semantic->process('template.html', $vars);

# text reference
my $res = Template::Semantic->process(\'<html><body>foo</body></html>', $vars);

# file handle, GLOB
my $res = Template::Semantic->process($fh, $vars);
my $res = Template::Semantic->process(\*DATA, $vars);

The second parameter is a value set to bind the template. $vars should be a hash-ref of selectors and corresponding values. See the "SELECTOR" and "VALUE TYPE" sections below. For example:

{
  '.foo'    => 'hello',
  '//title' => 'This is a title',
}
$ts->define_filter($filter_name, \&code)
$ts->call_filter($filter_name)

See the "Filter" section.

SELECTOR

Use XPath expression or CSS selector as a selector. If the expression doesn't look like XPath, it is considered CSS selector and converted into XPath internally.

print Template::Semantic->process($template, {
    
    # XPath sample that indicate <tag>
    '/html/body/h2[2]' => ...,
    '//title | //h1'   => ...,
    '//img[@id="foo"]' => ...,
    'id("foo")'        => ...,
    
    # XPath sample that indicate @attr
    '//a[@id="foo"]/@href'              => ...,
    '//meta[@name="keywords"]/@content' => ...,
    
    # CSS selector sample that indicate <tag>
    'title'         => ...,
    '#foo'          => ...,
    '.foo span.bar' => ...,
    
    # CSS selector sample that indicate @attr
    'img#foo@src'     => ...,
    'span.bar a@href' => ...,
    '@alt, @title'    => ...,

});

Template::Semantic allows some selector syntax that is different from usual XPath for your convenience.

1. You can use xpath '//div' without using XML::LibXML::XPathContext even if your template has default namespace (<html xmlns="...">).

2. You can use 'id("foo")' function to find element with id="foo" instead of xml:id="foo" without DTD. Note: use '//*[@xml:id="foo"]' if your template uses xml:id="foo".

3. You can '@attr' syntax with CSS selector that specifies the attribute. This is original syntax of this module.

VALUE TYPE

Basics

  • selector => $text

    Scalar: Replace the inner content with this as Text.

    $ts->process($template, {
        'h1' => 'foo & bar',   # <h1></h1> =>
                               # <h1>foo &amp; bar</h1>
         
        '.foo@href' => '/foo', # <a href="#" class="foo">bar</a> =>
                               # <a href="/foo" class="foo">bar</a>
    });
  • selector => \$html

    Scalar-ref: Replace the inner content with this as fragment XML/HTML.

    $ts->process($template, {
        'h1' => \'<a href="#">foo</a>bar', # <h1></h1> =>
                                           # <h1><a href="#">foo</a>bar</h1>
    });
  • selector => undef

    undef: Delete the element/attirbute that the selector indicates.

    $ts->process($template, {
        'h1'            => undef, # <div><h1>foo</h1>bar</div> =>
                                  # <div>bar</div>
        
        'div.foo@class' => undef, # <div class="foo">foo</div> =>
                                  # <div>foo</div>
    });
  • selector => XML::LibXML::Node

    Replace the inner content by the node. XML::LibXML::Attr isn't supported.

    $ts->process($template, {
        'h1' => do { XML::LibXML::Text->new('foo') },
    });
  • selector => Template::Semantic::Document

    Replace the inner content by another process()-ed result.

    $ts->process('wrapper.html', {
        'div#content' => $ts->process('inner.html', ...),
    });
  • selector => { 'selector' => $value, ... }

    Hash-ref: Sub query of the part.

    $ts->process($template, {
        # All <a> tag *in <div class="foo">* disappears
        'div.foo' => {
            'a' => undef,
        },
        
        # same as above
        'div.foo a' => undef,
        
        # xpath '.' = current node (itself)
        'a#bar' => {
            '.'       => 'foobar',
            './@href' => 'foo.html',
        },
        
        # same as above
        'a#bar'       => 'foobar',
        'a#bar/@href' => 'foo.html',
    });

Loop

  • selector => [ \%row, \%row, ... ]

    Array-ref of Hash-refs: Loop the part as template. Each item of the array-ref should be hash-ref.

    $ts->process(\*DATA, {
        'table.list tr' => [
            { 'th' => 'aaa', 'td' => '001' },
            { 'th' => 'bbb', 'td' => '002' },
            { 'th' => 'ccc', 'td' => '003' },
        ],
    });
    
    __DATA__
    <table class="list">
        <tr>
            <th></th>
            <td></td>
        </tr>
    </table>

    Output:

    <table class="list">
        <tr>
            <th>aaa</th>
            <td>001</td>
        </tr>
        <tr>
            <th>bbb</th>
            <td>002</td>
        </tr>
        <tr>
            <th>ccc</th>
            <td>003</td>
        </tr>
    </table>

Callback

  • selector => \&foo

    Code-ref: Callback subroutine. The callback receives

    $_    => innerHTML
    $_[0] => XML::LibXML::Node object (X::L::Element, X::L::Attr, ...)

    Its return value is handled per this list of value types (scalar to replace content, undef to delete, etc.).

    $ts->process($template, {
        # samples
        'h1' => sub { "bar" }, # <h1>foo</h1> => <h1>bar</h1>
        'h1' => sub { undef }, # <h1>foo</h1> => disappears
        
        # sample: use $_
        'h1' => sub { uc },  # <h1>foo</h1> => <h1>FOO</h1>
        
        # sample: use $_[0]
        'h1' => sub {
            my $node = shift;
            $node->nodeName; # <h1>foo</h1> => <h1>h1</h1>
        },
    });

Filter

  • selector => [ $value, filter, filter, ... ]

    Array-ref of Scalars: Value and filters. Filters may be

    A) Callback subroutine (code reference)

    B) Defined filter name

    C) Object like Text::Pipe (it->can('filter'))

    $ts->process($template, {
        'h1' => [ 'foo', sub { uc }, sub { "$_!" } ], # => <h1>FOO!</h1>
        'h2' => [ ' foo ', 'trim', sub { "$_!" } ],   # => <h2>FOO!</h2>
        'h3' => [ 'foo', PIPE('UppercaseFirst') ],    # => <h3>Foo</h3>
    });
    Defined basic filters

    Some basic filters included. See Template::Semantic::Filter.

    $ts->define_filter($filter_name, \&code)

    You can define your own filters using define_filter().

    use Text::Markdown qw/markdown/;
    $ts->define_filter(markdown => sub { \ markdown($_) })
    $ts->process($template, {
        'div.content' => [ $text, 'markdown' ],
    });
    $code = $ts->call_filter($filter_name)

    Accessor to defined filter.

    $ts->process($template, {
        'div.entry'      => ...,
        'div.entry-more' => ...,
    })->process({
        'div.entry, div.entry-more' => $ts->call_filter('markdown'),
    });

SEE ALSO

Template::Semantic::Cookbook

Template::Semantic::Document

XML::LibXML, HTML::Selector::XPath

I got a lot of ideas from Template, Template::Refine, Web::Scraper. thanks!

AUTHOR

Naoki Tomita <tomita@cpan.org>

Feedback, patches, POD English check are always welcome!

LICENSE

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.