PHP CSS Parser

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.

Usage

Installation using composer

Add php-css-parser to your composer.json

{
    "require": {
        "sabberworm/php-css-parser": "*"
    }
}

Extraction

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

new Sabberworm\CSS\Parser($sText);

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

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

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

Options

Charset

The charset option is used only if no @charset declaration is found in the CSS file. 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.

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

Strict parsing

To have the parser choke on invalid rules, supply a thusly configured Sabberworm\CSS\Settings object:

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

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 to use this with input you have no control over as it’s not thoroughly covered by test cases.

$oSettings = Sabberworm\CSS\Settings::create()->withMultibyteSupport(false);
new Sabberworm\CSS\Parser($sText, $oSettings);

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. CSSList has the following concrete subtypes:

• Document – representing the root of a CSS file.
• MediaQuery – represents a subsection of a CSSList that only applies to a output device matching the contained media query.

To access the items stored in a CSSList – like the document you got back when calling $oCssParser->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 which do not match the ones specifically mentioned like @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 $oRule), getRules() and removeRule($mRule) (which accepts either a Rule instance or a rule name; optionally suffixed by a dash to remove all related rules).

Rule

Rules just have a key (the rule) and a value. These values are all instances of 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 multi-valued 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 your selectors are. Aliased as getAllSelectors().
• getAllRuleSets() – does what it says; no matter how deeply nested your rule sets are.
• getAllValues() – finds all Value objects inside Rules.

To-Do

• More convenience methods [like selectorsWithElement($sId/Class/TagName), attributesOfType($sType), removeAttributesOfType($sType)]
• 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

$sMyId = "#my_id";
$oParser = new Sabberworm\CSS\Parser($sText);
$oCss = $oParser->parse();
foreach($oCss->getAllDeclarationBlocks() as $oBlock) {
	foreach($oBlock->getSelectors() as $oSelector) {
		//Loop over all selector parts (the comma-separated strings in a selector) and prepend the id
		$oSelector->setSelector($sMyId.' '.$oSelector->getSelector());
	}
}

Shrink all absolute sizes to half

$oParser = new Sabberworm\CSS\Parser($sText);
$oCss = $oParser->parse();
foreach($oCss->getAllValues() as $mValue) {
	if($mValue instanceof CSSSize && !$mValue->isRelative()) {
		$mValue->setSize($mValue->getSize()/2);
	}
}

Remove unwanted rules

$oParser = new Sabberworm\CSS\Parser($sText);
$oCss = $oParser->parse();
foreach($oCss->getAllRuleSets() as $oRuleSet) {
	$oRuleSet->removeRule('font-'); //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('cursor');
}

Output

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

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

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

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

Or use one of the predefined formats:

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

To see what you can do with output formatting, look at the tests in tests/Sabberworm/CSS/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; }
}

Structure (var_dump())

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;
}

Structure (var_dump())

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

• raxbg for contributions to parse calc, grid lines, and various bugfixes.
• 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 http://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/phpunit/phpunit/phpunit.

License

PHP-CSS-Parser is freely distributable under the terms of an MIT-style license.

Copyright (c) 2011 Raphael Schweikert, http://sabberworm.com/

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.