package CSS::Tiny;
=pod
=head1 NAME
CSS::Tiny - Read/Write .css files with as little code as possible
=head1 SYNOPSIS
# In your .css file
H1 { color: blue }
H2 { color: red; font-family: Arial }
.this, .that { color: yellow }
# In your program
use CSS::Tiny;
# Create a CSS stylesheet
my $CSS = CSS::Tiny->new();
# Open a CSS stylesheet
$CSS = CSS::Tiny->read( 'style.css' );
# Reading properties
my $header_color = $CSS->{H1}->{color};
my $header2_hashref = $CSS->{H2};
my $this_color = $CSS->{'.this'}->{color};
my $that_color = $CSS->{'.that'}->{color};
# Changing styles and properties
$CSS->{'.newstyle'} = { color => '#FFFFFF' }; # Add a style
$CSS->{H1}->{color} = 'black'; # Change a property
delete $CSS->{H2}; # Delete a style
# Save a CSS stylesheet
$CSS->write( 'style.css' );
# Get the CSS as a <style>...</style> tag
$CSS->html;
=head1 DESCRIPTION
C<CSS::Tiny> is a perl class to read and write .css stylesheets with as
little code as possible, reducing load time and memory overhead. CSS.pm
requires about 2.6 meg or ram to load, which is a large amount of
overhead if you only want to do trivial things.
Memory usage is normally scoffed at in Perl, but in my opinion should be
at least kept in mind.
This module is primarily for reading and writing simple files, and anything
we write shouldn't need to have documentation/comments. If you need
something with more power, move up to CSS.pm. With the increasing complexity
of CSS, this is becoming more common, but many situations can still live
with simple CSS files.
=head2 CSS Feature Support
C<CSS::Tiny> supports grouped styles of the form
C<this, that { color: blue }> correctly when reading, ungrouping them into
the hash structure. However, it will not restore the grouping should you
write the file back out. In this case, an entry in the original file of
the form
H1, H2 { color: blue }
would become
H1 { color: blue }
H2 { color: blue }
C<CSS::Tiny> handles nested styles of the form C<P EM { color: red }>
in reads and writes correctly, making the property available in the
form
$CSS->{'P EM'}->{color}
C<CSS::Tiny> ignores comments of the form C</* comment */> on read
correctly, however these comments will not be written back out to the
file.
=head1 CSS FILE SYNTAX
Files are written in a relatively human-orientated form, as follows:
H1 {
color: blue;
}
.this {
color: red;
font-size: 10px;
}
P EM {
color: yellow;
}
When reading and writing, all property descriptors, for example C<color>
and C<font-size> in the example above, are converted to lower case. As an
example, take the following CSS.
P {
Font-Family: Verdana;
}
To get the value C<'Verdana'> from the object C<$CSS>, you should
reference the key C<$CSS-E<gt>{P}-E<gt>{font-family}>.
=head1 METHODS
=cut
use strict;
use vars qw{$VERSION $errstr};
BEGIN {
$VERSION = '1.11';
$errstr = '';
}
=pod
=head2 new
The constructor C<new> creates and returns an empty C<CSS::Tiny> object.
=cut
sub new { bless {}, shift }
=pod
=head2 read $filename
The C<read> constructor reads a CSS stylesheet, and returns a new
C<CSS::Tiny> object containing the properties in the file.
Returns the object on success, or C<undef> on error.
=cut
sub read {
my $class = shift;
# Check the file
my $file = shift or return $class->_error( 'You did not specify a file name' );
return $class->_error( "The file '$file' does not exist" ) unless -e $file;
return $class->_error( "'$file' is a directory, not a file" ) unless -f _;
return $class->_error( "Insufficient permissions to read '$file'" ) unless -r _;
# Read the file
local $/ = undef;
open( CSS, $file ) or return $class->_error( "Failed to open file '$file': $!" );
my $contents = <CSS>;
close( CSS );
$class->read_string( $contents )
}
=pod
=head2 read_string $string
The C<read_string> constructor reads a CSS stylesheet from a string.
Returns the object on success, or C<undef> on error.
=cut
sub read_string {
my $self = bless {}, shift;
# Flatten whitespace and remove /* comment */ style comments
my $string = shift;
$string =~ tr/\n\t/ /;
$string =~ s!/\*.*?\*\/!!g;
# Split into styles
foreach ( grep { /\S/ } split /(?<=\})/, $string ) {
unless ( /^\s*([^{]+?)\s*\{(.*)\}\s*$/ ) {
return $self->_error( "Invalid or unexpected style data '$_'" );
}
# Split in such a way as to support grouped styles
my $style = $1;
$style =~ s/\s{2,}/ /g;
my @styles = grep { s/\s+/ /g; 1; } grep { /\S/ } split /\s*,\s*/, $style;
foreach ( @styles ) { $self->{$_} ||= {} }
# Split into properties
foreach ( grep { /\S/ } split /\;/, $2 ) {
unless ( /^\s*([\w._-]+)\s*:\s*(.*?)\s*$/ ) {
return $self->_error( "Invalid or unexpected property '$_' in style '$style'" );
}
foreach ( @styles ) { $self->{$_}->{lc $1} = $2 }
}
}
$self
}
=pod
=head2 clone
The C<clone> method creates an identical copy of an existing C<CSS::Tiny>
object.
=cut
BEGIN {
eval "use Clone 'clone';";
eval <<'END_METHOD' if $@;
sub clone {
my $self = shift;
my $copy = ref($self)->new;
foreach my $key ( keys %$self ) {
my $section = $self->{$key};
$copy->{$key} = {};
foreach ( keys %$section ) {
$copy->{$key}->{$_} = $section->{$_};
}
}
$copy;
}
END_METHOD
}
=pod
=head2 write
The C<write $filename> generates the stylesheet for the properties, and
writes it to disk. Returns true on success. Returns C<undef> on error.
=cut
sub write {
my $self = shift;
my $file = shift or return $self->_error( 'No file name provided' );
# Write the file
open( CSS, '>'. $file ) or return $self->_error( "Failed to open file '$file' for writing: $!" );
print CSS $self->write_string;
close( CSS );
1
}
=pod
=head2 write_string
Generates the stylesheet for the object and returns it as a string.
=cut
sub write_string {
my $self = shift;
# Iterate over the styles
# Note: We use 'reverse' in the sort to avoid a special case related
my $contents = '';
foreach my $style ( reverse sort keys %$self ) {
$contents .= "$style {\n";
foreach ( sort keys %{ $self->{$style} } ) {
$contents .= "\t" . lc($_) . ": $self->{$style}->{$_};\n";
}
$contents .= "}\n";
}
$contents
}
=pod
=head2 html
The C<html> method generates the CSS, but wrapped in a C<style> HTML tag,
so that it can be dropped directly onto a HTML page.
=cut
sub html {
my $css = $_[0]->write_string or return '';
"<style type=\"text/css\">\n<!--\n${css}-->\n</style>";
}
=pod
=head2 xhtml
The C<html> method generates the CSS, but wrapped in a C<style> XHTML tag,
so that it can be dropped directly onto an XHTML page.
=cut
sub xhtml {
my $css = $_[0]->write_string or return '';
"<style type=\"text/css\">\n/* <![CDATA[ */\n${css}/* ]]> */\n</style>";
}
=pod
=head2 errstr
When an error occurs, you can retrieve the error message either from the
C<$CSS::Tiny::errstr> variable, or using the C<errstr> method.
=cut
sub errstr { $errstr }
sub _error { $errstr = $_[1]; undef }
1;
=pod
=head1 SUPPORT
Bugs should be reported via the CPAN bug tracker at
For other issues, or commercial enhancement or support, contact the author.
=head1 AUTHOR
Adam Kennedy E<lt>cpan@ali.asE<gt>, L<http://ali.as/>
=head1 SEE ALSO
L<CSS>, L<http://www.w3.org/TR/REC-CSS1>, L<Config::Tiny>
=head1 COPYRIGHT
Copyright 2002 - 2005 Adam Kennedy. All rights reserved.
This program is free software; you can redistribute
it and/or modify it under the same terms as Perl itself.
The full text of the license can be found in the
LICENSE file included with this module.
=cut