/ 
CSS-Object-v0.2.0
River stage one • 2 direct dependents • 3 total dependents
/ CSS::Object

NAME

CSS::Object - CSS Object Oriented

SYNOPSIS

use CSS::Object;
use LWP::UserAgent;
my $ua = LWP::UserAgent->new;
my $resp = $ua->get( $style_uri );
die( $resp->message ) if( $resp->is_error );
my $style = $resp->decoded_content;
my $css = CSS::Object->new;
$css->read_string( $style );
$css->rules->foreach(sub
{
    my $rule = shift( @_ );
    # more processing
});

or, parsing inline stylesheets from a remote document:

use HTML::Object;
use HTML::Object::XQuery;
use LWP::UserAgent;
my $ua = LWP::UserAgent->new;
my $resp = $ua->get( $document_uri );
die( $resp->message ) if( $resp->is_error );
my $html = $resp->decoded_content;
my $parser = HTML::Object->new;
my $doc = $parser->parse( $html ) || die( $parser->error );
my $styles = $doc->find( 'style' ) || die( $doc->error );
say "Nothing found", exit(0) unless( $styles->length > 0 );
my $data = $styles->children->first->text();
my $css = CSS::Object->new;
$css->read_string( $data );
$css->rules->foreach(sub
{
    my $rule = shift( @_ );
    # more processing
});

Creating dynamically rules:

use CSS::Object;
my $css = CSS::Object->new ||
    die( CSS::Object->error );
my $b = $css->builder;
$b->select( ['#main_section > .article', 'section .article'] )
    ->display( 'none' )
    ->font_size( '+0.2rem' )
    ->comment( ['Some multiline comment', 'that are made possible with array reference'] )
    ->text_align( 'center' )
    ->comment( 'Making it look pretty' )
    ->padding( 5 );
$b->charset( 'UTF-8' );
$b->at( _webkit_keyframes => 'error' )
    ->frame( 0, { _webkit_transform => 'translateX( 0px )' })
    ->frame( 25, { _webkit_transform => 'translateX( 30px )' })
    ->frame( 45, { _webkit_transform => 'translateX( -30px )' })
    ->frame( 65, { _webkit_transform => 'translateX( 30px )' })
    ->frame( 82, { _webkit_transform => 'translateX( -30px )' })
    ->frame( 94, { _webkit_transform => 'translateX( 30px )' })
    ->frame( [qw( 35 55 75 87 97 100 )], { _webkit_transform => 'translateX( 0px )' } );
say $css->as_string;

VERSION

v0.2.0

DESCRIPTION

CSS::Object is a object oriented CSS parser and manipulation interface.

CONSTRUCTOR

new

To instantiate a new CSS::Object object, pass an hash reference of following parameters:

debug

This is an integer. The bigger it is and the more verbose is the output.

format

This is a CSS::Object::Format object or one of its child modules.

parser

This is a CSS::Object::Parser object or one of its child modules.

EXCEPTION HANDLING

Whenever an error has occurred, CSS::Object will set a Module::Generic::Exception object containing the detail of the error and return undef.

The error object can be retrieved with the inherited "error" in Module::Generic method. For example:

my $css = CSS::Object->new( debug => 3 ) || die( CSS::Object->error );

METHODS

add_element

Provided with a CSS::Object::Element object and this adds it to the list of css elements.

It uses an array object "elements" which is an Module::Generic::Array object.

add_rule

Provided with a CSS::Object::Rule object and this adds it to our list of rules. It returns the rule object that was added.

as_string

This will return the css data structure, currently registered, as a string.

It takes an optional CSS::Object::Format object as a parameter, to control the output. If none are provided, it will use the default one calling "format"

builder

This returns a new CSS::Object::Builder object.

charset

This sets or gets the css charset. It stores the value in a Module::Generic::Scalar object.

elements

Sets or gets the array of CSS elements. This is a Module::Generic::Array object that accepts only CSS::Object::Element objects or its child classes, such as CSS::Object::Rule, CSS::Object::Comment, etc

format

Sets or gets a CSS::Object::Format object. See "as_string" below for more detail about their use.

CSS::Object::Format objects control the stringification of the css structure. By default, it will return the data in a string identical or at least very similar to the one parsed if it was parsed.

get_rule_by_selector

Provided with a selector and this returns a CSS::Object::Rule object or an empty string.

Hoever, if this method is called in an object context, such as chaining, then it returns a Module::Generic::Null object instead of an empty string to prevent the perl error of xxx method called on an undefined value. For example:

$css->get_rule_by_selector( '.does-not-exists' )->add_element( $elem ) ||
die( "Unable to add css element to rule \".does-not-exists\": ", $css->error );

But, in a non-object context, such as:

my $rule = $css->get_rule_by_selector( '.does-not-exists' ) ||
die( "Unable to add css element to rule \".does-not-exists\": ", $css->error );

"get_rule_by_selector" will return an empty value.

load_parser

This will instantiate a new object based on the parser name specified with "parser" or during css object instantiation.

It returns a new CSS::Object::Parser object, or one of its child module matching the "parser" specified.

new_comment

This returns a new CSS::Object::Comment object and pass its instantiation method the provided arguments.

return( $css->new_comment( $array_ref_of_comment_ilnes ) );

new_property

This takes a property name, and an optional value o array of values and return a new CSS::Object::Property object

new_rule

This returns a new CSS::Object::Rule object.

new_selector

This takes a selector name and returns a new CSS::Object::Selector object.

new_value

This takes a property value and returns a new CSS::Object::Value object.

parse_string

Provided with some css data and this will instantiate the "parser", call "parse_string" in CSS::Object::Parser and returns an array of CSS::Object::Rule objects. The array is an array object from Module::Generic::Array and can be used as a regular array or as an object.

parser

Sets or gets the CSS::Object::Parser object to be used by "parse_string" to parse css data.

A valid parser object can be from CSS::Object::Parser or any of its sub modules.

It returns the current parser object.

purge

This empties the array containing all the CSS::Object::Rule objects.

read_file

Provided with a css file, and this will load it into memory and parse it using the parser name registered with "parser".

It can also take an array reference of css files who will be each fed to "read_file"

It returns the CSS::Object used to call this method.

read_string

Provided with some css data, and this will call "parse_string". It also accepts an array reference of data.

It returns the css object used to call this method.

rules

This sets or gets the Module::Generic::Array object used to store all the CSS::Object::Rule objects.

AUTHOR

Jacques Deguest <jack@deguest.jp>

SEE ALSO

CSS::Object

Mozilla documentation on Custom CSS Properties

COPYRIGHT & LICENSE

Copyright (c) 2020 DEGUEST Pte. Ltd.

You can use, copy, modify and redistribute this package and associated files under the same terms as Perl itself.