SYNOPSIS

use CSS::Squish;
my $concatenated = CSS::Squish->concatenate(@files);
my $squisher = CSS::Squish->new( roots => ['/root1', '/root2'] );
my $concatenated = $squisher->concatenate(@files);

DESCRIPTION

The benefit of this is that you get to keep your CSS as individual files, but can serve it to users in one big file, saving the overhead of possibly dozens of HTTP requests.

Following the CSS 2.1 spec, @import statements must be the first rules in a CSS file. Media-specific @import statements will be honored by enclosing the included file in an @media rule. This has the side effect of actually improving compatibility in Internet Explorer, which ignores media-specific @import rules but understands @media rules.

It is possible that future versions will include methods to compact whitespace and other parts of the CSS itself, but this functionality is not supported at the current time.

COMMON METHODS

new( [roots=>[...]] )

if you're using persistent environment (like mod_perl) then it's very recomended to use objects.

concatenate( @files )

concatenate_to( $dest, @files )

RESOLVING METHODS

In common situation you control CSS and can adopt it to use imports with relative URIs and most probably only have to set root(s).

However, you can subclass these methods to parse css files before submitting, implement advanced mapping of URIs to file system and other things.

Mapping works in the following way. When you call concatenate method we get content of file using file_handle method which as well lookup files in roots. If roots are not defined then files are treated as absolute paths or relative to the current directory. Using of absolute paths is not recommended as unhide server dirrectory layout to clients in css comments and as well don't allow to handle @import commands with absolute URIs. When files is found we parse its content for @import commands. On each URI we call resolve_uri method that convert absolute and relative URIs into file paths.

Here is example of processing:

    roots: /www/overlay/, /www/shared/
    $squisher->concatenate('/css/main.css');
    
    ->file_handle('/css/main.css');
        ->resolve_file('/css/main.css');
        <- '/www/shared/css/main.css';
    <- handle;
    content parsing
    find '@import url(nav.css)'
    -> resolve_uri('nav.css', '/css/main.css');
    <- '/css/nav.css';
        ... recursivly process file
    find '@import url(/css/another.css)'
    -> resolve_uri('/css/another.css', '/css/main.css');
    <- '/css/another.css'
    ...

roots( @dirs )

The paths specified here are searched for files. This is useful if your server has multiple document roots or document root doesn't match the current dir.

See also 'resolve_file' below.

file_handle( $file )

Returns undef if file couldn't be resolved or it's impossible to open file.

You can subclass it to filter content, process it with templating system or generate it on the fly:

    package My::CSS::Squish;
    use base qw(CSS::Squish);
    sub file_handle {
        my $self = shift;
        my $file = shift;
        
        my $content = $self->my_prepare_content($file);
        return undef unless defined $content;
        open my $fh, "<", \$content or warn "Couldn't open handle: $!";
        return $fh;
    }

Note that the file is not resolved yet and is relative to the root(s), so you have to resolve it yourself or call resolve_file method.

resolve_file( $file )

When roots are not set just checks if file exists.

_resolve_file( $file, @roots )

resolve_uri( $uri_string, $base_file )

AUTHOR

COPYRIGHT AND LICENSE

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.3 or, at your option, any later version of Perl 5 you may have available.