README

#CSS reader and writer

##Introduction CSS reader and writer with full CSS3 support, already supporting huge parts of the current CSS4 spec. It supports media queries, comments, value optimization and more... It offers full Unicode support and can handle also large CSS sources.

##Installation This is a composer package. See the composer website for basic installation information.

Add the following line to your composer.json file:

{
    "require": {
        "crossjoin/css": "1.0.*"
    }
}

###Requirements

PHP 5.4+
Multibyte String (mbstring) extension
DOM extension (to extract CSS from HTML sources)

##Features

Full CSS3 support
Full Unicode support
Support for huge parts of CSS4
Supports at-rules with an unlimited level of nesting
Supports CSS comments
Can handle large, compressed CSS files
Integrated checks for invalid CSS
...

##Basic usage

###Reading CSS You can read the CSS information from different sources.

// Read CSS file
$cssFileName = "path/to/file.css";
$reader = new \Crossjoin\Css\Reader\CssFile($cssFileName);

// Read CSS string
$cssString = "body { background:red; }";
$reader = new \Crossjoin\Css\Reader\CssFile($cssString);

// Extract CSS from <style> tags in a HTML file
// (multiple tags are merges to one style sheet)
$htmlFileName = "path/to/file.html";
$reader = new \Crossjoin\Css\Reader\HtmlFile($htmlFileName);

// Extract CSS from <style> tags in a HTML string
// (multiple tags are merges to one style sheet)
$htmlString = "<html><head><style>body{color:red;}</style></head><body></body></html>";
$reader = new \Crossjoin\Css\Reader\HtmlFile($htmlString);

###Charset detection The charset of the CSS file is detected automatically (depending on Byte-Order-Markers or a charset rule within the CSS) and defaults to "UTF-8". You can change the default value by setting the environment encoding.

// Sets the environment encoding of the referencing (!) document, e.g. if defined 
// in a link tag of an HTML page.
// This is used as a fall back value to determine the charset of the CSS file.
$reader->setEnvironmentEncoding("UTF-8");

###Writing CSS The writer can create CSS in different formats.

// Gets the CSS content in compact format (no comments, no line breaks,...)
$writer = new \Crossjoin\Css\Writer\Compact($reader->getStyleSheet());
$cssContent = $writer->getContent();

// Gets the CSS content in prettified format
// (with comments, line breaks, indentations,...)
$writer = new \Crossjoin\Css\Writer\Pretty($reader->getStyleSheet());
$cssContent = $writer->getContent();

###Error handling While parsing the CSS source, the content is checked for invalid rules, selectors and declarations. Furthermore the reader and the writer do additional checks regarding the composition of the rules, e.g. invalid rule positions or unnecessary empty rules.

$cssString = 'body{color:black} @charset "UTF-8"; @media print{@page{margin:1cm;}}';
$reader = new \Crossjoin\Css\Reader\CssString($cssString);
$writer = new \Crossjoin\Css\Writer\Pretty($reader->getStyleSheet());
$content = $writer->getContent();
$errors = $writer->getErrors();

print_r($content);
// body { color: black; }

print_r($errors);
// Array (
// [0] => Ignored @charset rule, because at wrong position in style sheet.
// [1] => Rule instance of type 'Crossjoin\Css\Format\Rule\AtPage\PageRule'
//        not allowed in conditional group rule of type
//        'Crossjoin\Css\Format\Rule\AtMedia\MediaRule'.
// [2] => Empty media at-rule '@media print' ignored.
// )

##Advanced usage TODO

##To Do

Additional checks for valid CSS rules, properties and values
Additional optimizations of CSS properties and values
Optimized auto-correction of invalid CSS, following the specs (example)
Support for CSS Paged Media Module Level 3 (page type selectors, margin at-rules)
Support for "supports" in import at-rule (not final)

crossjoin / css

Maintainers

Details

README