<?php
namespace TijsVerkoyen\CssToInlineStyles\Css\Rule;
use Symfony\Component\CssSelector\Node\Specificity;
use \TijsVerkoyen\CssToInlineStyles\Css\Property\Processor as PropertyProcessor;
class Processor
{
/**
* Splits a string into separate rules
*
* @param string $rulesString
*
* @return string[]
*/
public function splitIntoSeparateRules($rulesString)
{
$rulesString = $this->cleanup($rulesString);
return (array) explode('}', $rulesString);
}
/**
* @param string $string
*
* @return string
*/
private function cleanup($string)
{
$string = str_replace(array("\r", "\n"), '', $string);
$string = str_replace(array("\t"), ' ', $string);
$string = str_replace('"', '\'', $string);
$string = preg_replace('|/\*.*?\*/|', '', $string);
$string = preg_replace('/\s\s+/', ' ', $string);
$string = trim($string);
$string = rtrim($string, '}');
return $string;
}
/**
* Converts a rule-string into an object
*
* @param string $rule
* @param int $originalOrder
*
* @return Rule[]
*/
public function convertToObjects($rule, $originalOrder)
{
$rule = $this->cleanup($rule);
$chunks = explode('{', $rule);
if (!isset($chunks[1])) {
return array();
}
$propertiesProcessor = new PropertyProcessor();
$rules = array();
$selectors = (array) explode(',', trim($chunks[0]));
$properties = $propertiesProcessor->splitIntoSeparateProperties($chunks[1]);
foreach ($selectors as $selector) {
$selector = trim($selector);
$specificity = $this->calculateSpecificityBasedOnASelector($selector);
$rules[] = new Rule(
$selector,
$propertiesProcessor->convertArrayToObjects($properties, $specificity),
$specificity,
$originalOrder
);
}
return $rules;
}
/**
* Calculates the specificity based on a CSS Selector string,
* Based on the patterns from premailer/css_parser by Alex Dunae
*
* @see https://github.com/premailer/css_parser/blob/master/lib/css_parser/regexps.rb
*
* @param string $selector
*
* @return Specificity
*/
public function calculateSpecificityBasedOnASelector($selector)
{
$idSelectorsPattern = " \#";
$classAttributesPseudoClassesSelectorsPattern = " (\.[\w]+) # classes
|
\[(\w+) # attributes
|
(\:( # pseudo classes
link|visited|active
|hover|focus
|lang
|target
|enabled|disabled|checked|indeterminate
|root
|nth-child|nth-last-child|nth-of-type|nth-last-of-type
|first-child|last-child|first-of-type|last-of-type
|only-child|only-of-type
|empty|contains
))";
$typePseudoElementsSelectorPattern = " ((^|[\s\+\>\~]+)[\w]+ # elements
|
\:{1,2}( # pseudo-elements
after|before
|first-letter|first-line
|selection
)
)";
return new Specificity(
preg_match_all("/{$idSelectorsPattern}/ix", $selector, $matches),
preg_match_all("/{$classAttributesPseudoClassesSelectorsPattern}/ix", $selector, $matches),
preg_match_all("/{$typePseudoElementsSelectorPattern}/ix", $selector, $matches)
);
}
/**
* @param string[] $rules
* @param Rule[] $objects
*
* @return Rule[]
*/
public function convertArrayToObjects(array $rules, array $objects = array())
{
$order = 1;
foreach ($rules as $rule) {
$objects = array_merge($objects, $this->convertToObjects($rule, $order));
$order++;
}
return $objects;
}
/**
* Sorts an array on the specificity element in an ascending way
* Lower specificity will be sorted to the beginning of the array
*
* @param Rule $e1 The first element.
* @param Rule $e2 The second element.
*
* @return int
*/
public static function sortOnSpecificity(Rule $e1, Rule $e2)
{
$e1Specificity = $e1->getSpecificity();
$value = $e1Specificity->compareTo($e2->getSpecificity());
// if the specificity is the same, use the order in which the element appeared
if ($value === 0) {
$value = $e1->getOrder() - $e2->getOrder();
}
return $value;
}
}