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CSS cpan:WARRINGD last updated on 2021-04-06


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class CSS

CSS Stylesheet processing


use CSS;
use CSS::Properties;
use CSS::Units :px; # define 'px' postfix operator
use CSS::TagSet::XHTML;
use LibXML::Document;

my $string = q:to<\_(ツ)_/>;
  <!DOCTYPE html>
        body {background-color: powderblue; font-size: 12pt}
        @media screen { h1:first-child {color: blue !important;} }
        @media print { h2 {color: green;} }
        p    {color: red;}
        div {font-size: 10pt }
      <h1>This is a heading</h1>
      <h2>This is a sub-heading</h2>
      <h1>This is another heading</h1>
      <p>This is a paragraph.</p>
      <div style="color:green">This is a div</div>

my LibXML::Document $doc .= parse: :$string, :html;

# define a selection media
my CSS::Media $media .= new: :type<screen>, :width(480px), :height(640px), :color;

# Create a tag-set for XHTML specific loading of style-sheets and styling
my CSS::TagSet::XHTML $tag-set .= new();

my CSS $css .= new: :$doc, :$tag-set, :$media, :inherit;

# show some computed styles, based on CSS Selectors, media, inline styles and xhtml tags

my CSS::Properties $body-props = $'/html/body');
say $body-props.font-size; # 12pt
say $body-props;           # background-color:powderblue; display:block; font-size:12pt; margin:8px; unicode-bidi:embed;
say $'/html/body/h1[1]');
# color:blue; display:block; font-size:12pt; font-weight:bolder; margin-bottom:0.67em; margin-top:0.67em; unicode-bidi:embed;
say $'/html/body/div');

# color:green; display:block; font-size:10pt; unicode-bidi:embed;
say $$doc.first('/html/body/div'));
# color:green; display:block; font-size:10pt; unicode-bidi:embed;


CSS is a module for parsing style-sheets and applying them to HTML or XML documents.

This module aims to be W3C compliant and complete, including: style-sheets, media specific and inline styling and the application of HTML specific styling (based on tags and attributes).


method new

method new(
    LibXML::Document :$doc!,       # document to be styled.
    CSS::Stylesheet :$stylesheet!, # stylesheet to apply
    CSS::TagSet :$tag-set,         # tag-specific styling
    CSS::Media :$media,            # target media
    Bool :$inherit = True,         # perform property inheritance
) returns CSS;

In particular, the CSS::TagSet :$tag-set options specifies a tag-specific styler; For example CSS::TagSet::XHTML.

method style

multi method style(LibXML::Element:D $elem) returns CSS::Properties;
multi method style(Str:D $xpath) returns CSS::Properties;

Computes a style for an individual element, or XPath to an element.

method prune

method prune(LibXML::Element $node? --> LibXML::Element)

Removes all XML nodes with CSS property display:none;, giving an approximate representation of a CSS rendering tree.

For example, for a XHTML tag-set the head element will be removed, along with any other elements that have had `display:none;' applied to them via inline CSS or CSS Selectors.

By default, this method acts on the root element of the associated $.doc XML document.


Utility Scripts

Rebuild a CSS Style-sheet with various checks and optimizations.

See Also