README

A Parser for CSS Files written in PHP. Allows extraction of CSS files into a data structure, manipulation of said structure and output as (optimized) CSS.

This is the Totara-specific fork, which adds on some Totara-specific compatibility feature/fixes. If you're not using Totara, highly recommend you use the original package.

Usage

Installation using Composer

composer require totara/php-css-parser

Extraction

To use the CSS Parser, create a new instance. The constructor takes the following form:

new \Sabberworm\CSS\Parser($css);

To read a file, for example, you’d do the following:

$parser = new \Sabberworm\CSS\Parser(file_get_contents('somefile.css')); $cssDocument = $parser->parse();

The resulting CSS document structure can be manipulated prior to being output.

Options

Charset

The charset option will only be used if the CSS file does not contain an @charset declaration. UTF-8 is the default, so you won’t have to create a settings object at all if you don’t intend to change that.

$settings = \Sabberworm\CSS\Settings::create() ->withDefaultCharset('windows-1252'); $parser = new \Sabberworm\CSS\Parser($css, $settings);

Strict parsing

To have the parser throw an exception when encountering invalid/unknown constructs (as opposed to trying to ignore them and carry on parsing), supply a thusly configured \Sabberworm\CSS\Settings object:

$parser = new \Sabberworm\CSS\Parser( file_get_contents('somefile.css'), \Sabberworm\CSS\Settings::create()->beStrict() );

Note that this will also disable a workaround for parsing the unquoted variant of the legacy IE-specific filter rule.

Disable multibyte functions

To achieve faster parsing, you can choose to have PHP-CSS-Parser use regular string functions instead of mb_* functions. This should work fine in most cases, even for UTF-8 files, as all the multibyte characters are in string literals. Still it’s not recommended using this with input you have no control over as it’s not thoroughly covered by test cases.

$settings = \Sabberworm\CSS\Settings::create()->withMultibyteSupport(false); $parser = new \Sabberworm\CSS\Parser($css, $settings);

Manipulation

The resulting data structure consists mainly of five basic types: CSSList, RuleSet, Rule, Selector and Value. There are two additional types used: Import and Charset, which you won’t use often.

CSSList

CSSList represents a generic CSS container, most likely containing declaration blocks (rule sets with a selector), but it may also contain at-rules, charset declarations, etc.

To access the items stored in a CSSList – like the document you got back when calling $parser->parse() –, use getContents(), then iterate over that collection and use instanceof to check whether you’re dealing with another CSSList, a RuleSet, a Import or a Charset.

To append a new item (selector, media query, etc.) to an existing CSSList, construct it using the constructor for this class and use the append($oItem) method.

RuleSet

RuleSet is a container for individual rules. The most common form of a rule set is one constrained by a selector. The following concrete subtypes exist:

• AtRuleSet – for generic at-rules for generic at-rules which are not covered by specific classes, i.e., not @import, @charset or @media. A common example for this is @font-face.
• DeclarationBlock – a RuleSet constrained by a Selector; contains an array of selector objects (comma-separated in the CSS) as well as the rules to be applied to the matching elements.

Note: A CSSList can contain other CSSLists (and Imports as well as a Charset), while a RuleSet can only contain Rules.

If you want to manipulate a RuleSet, use the methods addRule(Rule $rule), getRules() and removeRule($rule) (which accepts either a Rule or a rule name; optionally suffixed by a dash to remove all related rules).

Rule

Rules just have a string key (the rule) and a Value.

Value

Value is an abstract class that only defines the render method. The concrete subclasses for atomic value types are:

• Size – consists of a numeric size value and a unit.
• Color – colors can be input in the form #rrggbb, #rgb or schema(val1, val2, …) but are always stored as an array of ('s' => val1, 'c' => val2, 'h' => val3, …) and output in the second form.
• CSSString – this is just a wrapper for quoted strings to distinguish them from keywords; always output with double quotes.
• URL – URLs in CSS; always output in URL("") notation.

There is another abstract subclass of Value, ValueList: A ValueList represents a lists of Values, separated by some separation character (mostly ,, whitespace, or /).

There are two types of ValueLists:

• RuleValueList – The default type, used to represent all multivalued rules like font: bold 12px/3 Helvetica, Verdana, sans-serif; (where the value would be a whitespace-separated list of the primitive value bold, a slash-separated list and a comma-separated list).
• CSSFunction – A special kind of value that also contains a function name and where the values are the function’s arguments. Also handles equals-sign-separated argument lists like filter: alpha(opacity=90);.

Convenience methods

There are a few convenience methods on Document to ease finding, manipulating and deleting rules:

• getAllDeclarationBlocks() – does what it says; no matter how deeply nested the selectors are. Aliased as getAllSelectors().
• getAllRuleSets() – does what it says; no matter how deeply nested the rule sets are.
• getAllValues() – finds all Value objects inside Rules.

To-Do

• More convenience methods (like selectorsWithElement($sId/Class/TagName), attributesOfType($type), removeAttributesOfType($type))
• Real multibyte support. Currently, only multibyte charsets whose first 255 code points take up only one byte and are identical with ASCII are supported (yes, UTF-8 fits this description).
• Named color support (using Color instead of an anonymous string literal)

Use cases

Use Parser to prepend an ID to all selectors

$myId = "#my_id"; $parser = new \Sabberworm\CSS\Parser($css); $cssDocument = $parser->parse(); foreach ($cssDocument->getAllDeclarationBlocks() as $block) { foreach ($block->getSelectors() as $selector) { // Loop over all selector parts (the comma-separated strings in a // selector) and prepend the ID. $selector->setSelector($myId.' '.$selector->getSelector()); } }

Shrink all absolute sizes to half

$parser = new \Sabberworm\CSS\Parser($css); $cssDocument = $parser->parse(); foreach ($cssDocument->getAllValues() as $value) { if ($value instanceof CSSSize && !$value->isRelative()) { $value->setSize($value->getSize() / 2); } }

Remove unwanted rules

$parser = new \Sabberworm\CSS\Parser($css); $cssDocument = $parser->parse(); foreach($cssDocument->getAllRuleSets() as $oRuleSet) { // Note that the added dash will make this remove all rules starting with // `font-` (like `font-size`, `font-weight`, etc.) as well as a potential // `font` rule. $oRuleSet->removeRule('font-'); $oRuleSet->removeRule('cursor'); }

Output

To output the entire CSS document into a variable, just use ->render():

$parser = new \Sabberworm\CSS\Parser(file_get_contents('somefile.css')); $cssDocument = $parser->parse(); print $cssDocument->render();

If you want to format the output, pass an instance of type \Sabberworm\CSS\OutputFormat:

$format = \Sabberworm\CSS\OutputFormat::create() ->indentWithSpaces(4)->setSpaceBetweenRules("\n"); print $cssDocument->render($format);

Or use one of the predefined formats:

print $cssDocument->render(Sabberworm\CSS\OutputFormat::createPretty()); print $cssDocument->render(Sabberworm\CSS\OutputFormat::createCompact());

To see what you can do with output formatting, look at the tests in tests/OutputFormatTest.php.

Examples

Example 1 (At-Rules)

Input

@charset "utf-8"; @font-face { font-family: "CrassRoots"; src: url("../media/cr.ttf"); } html, body { font-size: 1.6em; } @keyframes mymove { from { top: 0px; } to { top: 200px; } }

class Sabberworm\CSS\CSSList\Document#4 (2) { protected $aContents => array(4) { [0] => class Sabberworm\CSS\Property\Charset#6 (2) { private $sCharset => class Sabberworm\CSS\Value\CSSString#5 (2) { private $sString => string(5) "utf-8"  protected $iLineNo =>  int(1)  }  protected $iLineNo =>  int(1)  }  [1] =>  class Sabberworm\CSS\RuleSet\AtRuleSet#7 (4) {  private $sType =>  string(9) "font-face" private $sArgs => string(0) ""  private $aRules =>  array(2) {  'font-family' =>  array(1) {  [0] =>  class Sabberworm\CSS\Rule\Rule#8 (4) {  private $sRule =>  string(11) "font-family" private $mValue => class Sabberworm\CSS\Value\CSSString#9 (2) { private $sString => string(10) "CrassRoots"  protected $iLineNo =>  int(4)  }  private $bIsImportant =>  bool(false)  protected $iLineNo =>  int(4)  }  }  'src' =>  array(1) {  [0] =>  class Sabberworm\CSS\Rule\Rule#10 (4) {  private $sRule =>  string(3) "src"  private $mValue =>  class Sabberworm\CSS\Value\URL#11 (2) {  private $oURL =>  class Sabberworm\CSS\Value\CSSString#12 (2) {  private $sString =>  string(15) "../media/cr.ttf" protected $iLineNo => int(5) } protected $iLineNo => int(5) } private $bIsImportant => bool(false) protected $iLineNo => int(5) } } } protected $iLineNo => int(3) } [2] => class Sabberworm\CSS\RuleSet\DeclarationBlock#13 (3) { private $aSelectors => array(2) { [0] => class Sabberworm\CSS\Property\Selector#14 (2) { private $sSelector => string(4) "html" private $iSpecificity => NULL } [1] => class Sabberworm\CSS\Property\Selector#15 (2) { private $sSelector => string(4) "body" private $iSpecificity => NULL } } private $aRules => array(1) { 'font-size' => array(1) { [0] => class Sabberworm\CSS\Rule\Rule#16 (4) { private $sRule => string(9) "font-size" private $mValue => class Sabberworm\CSS\Value\Size#17 (4) { private $fSize => double(1.6) private $sUnit => string(2) "em" private $bIsColorComponent => bool(false) protected $iLineNo => int(9) } private $bIsImportant => bool(false) protected $iLineNo => int(9) } } } protected $iLineNo => int(8) } [3] => class Sabberworm\CSS\CSSList\KeyFrame#18 (4) { private $vendorKeyFrame => string(9) "keyframes" private $animationName => string(6) "mymove" protected $aContents => array(2) { [0] => class Sabberworm\CSS\RuleSet\DeclarationBlock#19 (3) { private $aSelectors => array(1) { [0] => class Sabberworm\CSS\Property\Selector#20 (2) { private $sSelector => string(4) "from" private $iSpecificity => NULL } } private $aRules => array(1) { 'top' => array(1) { [0] => class Sabberworm\CSS\Rule\Rule#21 (4) { private $sRule => string(3) "top" private $mValue => class Sabberworm\CSS\Value\Size#22 (4) { private $fSize => double(0) private $sUnit => string(2) "px" private $bIsColorComponent => bool(false) protected $iLineNo => int(13) } private $bIsImportant => bool(false) protected $iLineNo => int(13) } } } protected $iLineNo => int(13) } [1] => class Sabberworm\CSS\RuleSet\DeclarationBlock#23 (3) { private $aSelectors => array(1) { [0] => class Sabberworm\CSS\Property\Selector#24 (2) { private $sSelector => string(2) "to" private $iSpecificity => NULL } } private $aRules => array(1) { 'top' => array(1) { [0] => class Sabberworm\CSS\Rule\Rule#25 (4) { private $sRule => string(3) "top" private $mValue => class Sabberworm\CSS\Value\Size#26 (4) { private $fSize => double(200) private $sUnit => string(2) "px" private $bIsColorComponent => bool(false) protected $iLineNo => int(14) } private $bIsImportant => bool(false) protected $iLineNo => int(14) } } } protected $iLineNo => int(14) } } protected $iLineNo => int(12) } } protected $iLineNo => int(1) }

Output (render())

@charset "utf-8"; @font-face {font-family: "CrassRoots";src: url("../media/cr.ttf");} html, body {font-size: 1.6em;} @keyframes mymove {from {top: 0px;} to {top: 200px;}}

Example 2 (Values)

Input

#header { margin: 10px 2em 1cm 2%; font-family: Verdana, Helvetica, "Gill Sans", sans-serif; color: red !important; }

class Sabberworm\CSS\CSSList\Document#4 (2) { protected $aContents => array(1) { [0] => class Sabberworm\CSS\RuleSet\DeclarationBlock#5 (3) { private $aSelectors => array(1) { [0] => class Sabberworm\CSS\Property\Selector#6 (2) { private $sSelector => string(7) "#header"  private $iSpecificity =>  NULL  }  }  private $aRules =>  array(3) {  'margin' =>  array(1) {  [0] =>  class Sabberworm\CSS\Rule\Rule#7 (4) {  private $sRule =>  string(6) "margin"  private $mValue =>  class Sabberworm\CSS\Value\RuleValueList#12 (3) {  protected $aComponents =>  array(4) {  [0] =>  class Sabberworm\CSS\Value\Size#8 (4) {  private $fSize =>  double(10)  private $sUnit =>  string(2) "px"  private $bIsColorComponent =>  bool(false)  protected $iLineNo =>  int(2)  }  [1] =>  class Sabberworm\CSS\Value\Size#9 (4) {  private $fSize =>  double(2)  private $sUnit =>  string(2) "em"  private $bIsColorComponent =>  bool(false)  protected $iLineNo =>  int(2)  }  [2] =>  class Sabberworm\CSS\Value\Size#10 (4) {  private $fSize =>  double(1)  private $sUnit =>  string(2) "cm"  private $bIsColorComponent =>  bool(false)  protected $iLineNo =>  int(2)  }  [3] =>  class Sabberworm\CSS\Value\Size#11 (4) {  private $fSize =>  double(2)  private $sUnit =>  string(1) "%"  private $bIsColorComponent =>  bool(false)  protected $iLineNo =>  int(2)  }  }  protected $sSeparator =>  string(1) " "  protected $iLineNo =>  int(2)  }  private $bIsImportant =>  bool(false)  protected $iLineNo =>  int(2)  }  }  'font-family' =>  array(1) {  [0] =>  class Sabberworm\CSS\Rule\Rule#13 (4) {  private $sRule =>  string(11) "font-family" private $mValue => class Sabberworm\CSS\Value\RuleValueList#15 (3) { protected $aComponents => array(4) { [0] => string(7) "Verdana" [1] => string(9) "Helvetica" [2] => class Sabberworm\CSS\Value\CSSString#14 (2) { private $sString => string(9) "Gill Sans" protected $iLineNo => int(3) } [3] => string(10) "sans-serif" } protected $sSeparator => string(1) "," protected $iLineNo => int(3) } private $bIsImportant => bool(false) protected $iLineNo => int(3) } } 'color' => array(1) { [0] => class Sabberworm\CSS\Rule\Rule#16 (4) { private $sRule => string(5) "color" private $mValue => string(3) "red" private $bIsImportant => bool(true) protected $iLineNo => int(4) } } } protected $iLineNo => int(1) } } protected $iLineNo => int(1) }

Output (render())

#header {margin: 10px 2em 1cm 2%;font-family: Verdana,Helvetica,"Gill Sans",sans-serif;color: red !important;}

Contributors/Thanks to

• oliverklee for lots of refactorings, code modernizations and CI integrations
• raxbg for contributions to parse calc, grid lines, and various bugfixes.
• westonruter for bugfixes and improvements.
• FMCorz for many patches and suggestions, for being able to parse comments and IE hacks (in lenient mode).
• Lullabot for a patch that allows to know the line number for each parsed token.
• ju1ius for the specificity parsing code and the ability to expand/compact shorthand properties.
• ossinkine for a 150 time performance boost.
• GaryJones for lots of input and https://css-specificity.info/.
• docteurklein for output formatting and CSSList->remove() inspiration.
• nicolopignatelli for PSR-0 compatibility.
• diegoembarcadero for keyframe at-rule parsing.
• goetas for @namespace at-rule support.
• View full list

Misc

• Legacy Support: The latest pre-PSR-0 version of this project can be checked with the 0.9.0 tag.
• Running Tests: To run all unit tests for this project, run composer install to install phpunit and use ./vendor/bin/phpunit.