snappymail/plugins/convert-headers-styles/CssToInlineStyles.php
2013-11-20 16:26:00 +04:00

700 lines
21 KiB
PHP

<?php
namespace TijsVerkoyen\CssToInlineStyles;
/**
* CSS to Inline Styles class
*
* @author Tijs Verkoyen <php-css-to-inline-styles@verkoyen.eu>
* @version 1.1.0
* @copyright Copyright (c), Tijs Verkoyen. All rights reserved.
* @license BSD License
*/
class CssToInlineStyles
{
/**
* The CSS to use
*
* @var string
*/
private $css;
/**
* The processed CSS rules
*
* @var array
*/
private $cssRules;
/**
* Should the generated HTML be cleaned
*
* @var bool
*/
private $cleanup = false;
/**
* The encoding to use.
*
* @var string
*/
private $encoding = 'UTF-8';
/**
* The HTML to process
*
* @var string
*/
private $html;
/**
* Use inline-styles block as CSS
*
* @var bool
*/
private $useInlineStylesBlock = false;
/*
* Strip original style tags
*
* @var bool
*/
private $stripOriginalStyleTags = false;
/**
* Creates an instance, you could set the HTML and CSS here, or load it
* later.
*
* @return void
* @param string[optional] $html The HTML to process.
* @param string[optional] $css The CSS to use.
*/
public function __construct($html = null, $css = null)
{
if($html !== null) $this->setHTML($html);
if($css !== null) $this->setCSS($css);
}
/**
* Convert a CSS-selector into an xPath-query
*
* @return string
* @param string $selector The CSS-selector.
*/
private function buildXPathQuery($selector)
{
// redefine
$selector = (string) $selector;
// the CSS selector
$cssSelector = array(
// E F, Matches any F element that is a descendant of an E element
'/(\w)\s+(\w)/',
// E > F, Matches any F element that is a child of an element E
'/(\w)\s*>\s*(\w)/',
// E:first-child, Matches element E when E is the first child of its parent
'/(\w):first-child/',
// E + F, Matches any F element immediately preceded by an element
'/(\w)\s*\+\s*(\w)/',
// E[foo], Matches any E element with the "foo" attribute set (whatever the value)
'/(\w)\[([\w\-]+)]/',
// E[foo="warning"], Matches any E element whose "foo" attribute value is exactly equal to "warning"
'/(\w)\[([\w\-]+)\=\"(.*)\"]/',
// div.warning, HTML only. The same as DIV[class~="warning"]
'/(\w+|\*)+\.([\w\-]+)+/',
// .warning, HTML only. The same as *[class~="warning"]
'/\.([\w\-]+)/',
// E#myid, Matches any E element with id-attribute equal to "myid"
'/(\w+)+\#([\w\-]+)/',
// #myid, Matches any element with id-attribute equal to "myid"
'/\#([\w\-]+)/'
);
// the xPath-equivalent
$xPathQuery = array(
// E F, Matches any F element that is a descendant of an E element
'\1//\2',
// E > F, Matches any F element that is a child of an element E
'\1/\2',
// E:first-child, Matches element E when E is the first child of its parent
'*[1]/self::\1',
// E + F, Matches any F element immediately preceded by an element
'\1/following-sibling::*[1]/self::\2',
// E[foo], Matches any E element with the "foo" attribute set (whatever the value)
'\1 [ @\2 ]',
// E[foo="warning"], Matches any E element whose "foo" attribute value is exactly equal to "warning"
'\1[ contains( concat( " ", @\2, " " ), concat( " ", "\3", " " ) ) ]',
// div.warning, HTML only. The same as DIV[class~="warning"]
'\1[ contains( concat( " ", @class, " " ), concat( " ", "\2", " " ) ) ]',
// .warning, HTML only. The same as *[class~="warning"]
'*[ contains( concat( " ", @class, " " ), concat( " ", "\1", " " ) ) ]',
// E#myid, Matches any E element with id-attribute equal to "myid"
'\1[ @id = "\2" ]',
// #myid, Matches any element with id-attribute equal to "myid"
'*[ @id = "\1" ]'
);
// return
$xPath = (string) '//' . preg_replace($cssSelector, $xPathQuery, $selector);
return str_replace('] *', ']//*', $xPath);
}
/**
* Calculate the specifity for the CSS-selector
*
* @return int
* @param string $selector The selector to calculate the specifity for.
*/
private function calculateCSSSpecifity($selector)
{
// cleanup selector
$selector = str_replace(array('>', '+'), array(' > ', ' + '), $selector);
// init var
$specifity = 0;
// split the selector into chunks based on spaces
$chunks = explode(' ', $selector);
// loop chunks
foreach ($chunks as $chunk) {
// an ID is important, so give it a high specifity
if(strstr($chunk, '#') !== false) $specifity += 100;
// classes are more important than a tag, but less important then an ID
elseif(strstr($chunk, '.')) $specifity += 10;
// anything else isn't that important
else $specifity += 1;
}
// return
return $specifity;
}
/**
* Cleanup the generated HTML
*
* @return string
* @param string $html The HTML to cleanup.
*/
private function cleanupHTML($html)
{
// remove classes
$html = preg_replace('/(\s)+class="(.*)"(\s)+/U', ' ', $html);
// remove IDs
$html = preg_replace('/(\s)+id="(.*)"(\s)+/U', ' ', $html);
// return
return $html;
}
/**
* Converts the loaded HTML into an HTML-string with inline styles based on the loaded CSS
*
* @return string
* @param bool[optional] $outputXHTML Should we output valid XHTML?
*/
public function convert($outputXHTML = false)
{
// redefine
$outputXHTML = (bool) $outputXHTML;
// validate
if($this->html == null) throw new Exception('No HTML provided.');
// should we use inline style-block
if ($this->useInlineStylesBlock) {
// init var
$matches = array();
// match the style blocks
preg_match_all('|<style(.*)>(.*)</style>|isU', $this->html, $matches);
// any style-blocks found?
if (!empty($matches[2])) {
// add
foreach($matches[2] as $match) $this->css .= trim($match) ."\n";
}
}
// process css
$this->processCSS();
// create new DOMDocument
$document = new \DOMDocument('1.0', $this->getEncoding());
// set error level
libxml_use_internal_errors(true);
// load HTML
// $document->loadHTML($this->html);
$document->loadHTML('<'.'?xml version="1.0" encoding="'.$this->getEncoding().'"?'.'><head><meta http-equiv="Content-Type" content="text/html; charset='.$this->getEncoding().'"></head>'.$this->html);
// create new XPath
$xPath = new \DOMXPath($document);
// any rules?
if (!empty($this->cssRules)) {
// loop rules
foreach ($this->cssRules as $rule) {
// init var
$query = $this->buildXPathQuery($rule['selector']);
// validate query
if($query === false) continue;
// search elements
$elements = $xPath->query($query);
// validate elements
if($elements === false) continue;
// loop found elements
foreach ($elements as $element) {
// no styles stored?
if ($element->attributes->getNamedItem(
'data-css-to-inline-styles-original-styles'
) == null) {
// init var
$originalStyle = '';
if ($element->attributes->getNamedItem('style') !== null) {
$originalStyle = $element->attributes->getNamedItem('style')->value;
}
// store original styles
$element->setAttribute(
'data-css-to-inline-styles-original-styles',
$originalStyle
);
// clear the styles
$element->setAttribute('style', '');
}
// init var
$properties = array();
// get current styles
$stylesAttribute = $element->attributes->getNamedItem('style');
// any styles defined before?
if ($stylesAttribute !== null) {
// get value for the styles attribute
$definedStyles = (string) $stylesAttribute->value;
// split into properties
$definedProperties = (array) explode(';', $definedStyles);
// loop properties
foreach ($definedProperties as $property) {
// validate property
if($property == '') continue;
// split into chunks
$chunks = (array) explode(':', trim($property), 2);
// validate
if(!isset($chunks[1])) continue;
// loop chunks
$properties[$chunks[0]] = trim($chunks[1]);
}
}
// add new properties into the list
foreach ($rule['properties'] as $key => $value) {
$properties[$key] = $value;
}
// build string
$propertyChunks = array();
// build chunks
foreach ($properties as $key => $values) {
foreach ((array) $values as $value) {
$propertyChunks[] = $key . ': ' . $value . ';';
}
}
// build properties string
$propertiesString = implode(' ', $propertyChunks);
// set attribute
if ($propertiesString != '') {
$element->setAttribute('style', $propertiesString);
}
}
}
// reapply original styles
$query = $this->buildXPathQuery(
'*[@data-css-to-inline-styles-original-styles]'
);
// validate query
if($query === false) return;
// search elements
$elements = $xPath->query($query);
// loop found elements
foreach ($elements as $element) {
// get the original styles
$originalStyle = $element->attributes->getNamedItem(
'data-css-to-inline-styles-original-styles'
)->value;
if ($originalStyle != '') {
$originalProperties = array();
$originalStyles = (array) explode(';', $originalStyle);
foreach ($originalStyles as $property) {
// validate property
if($property == '') continue;
// split into chunks
$chunks = (array) explode(':', trim($property), 2);
// validate
if(!isset($chunks[1])) continue;
// loop chunks
$originalProperties[$chunks[0]] = trim($chunks[1]);
}
// get current styles
$stylesAttribute = $element->attributes->getNamedItem('style');
$properties = array();
// any styles defined before?
if ($stylesAttribute !== null) {
// get value for the styles attribute
$definedStyles = (string) $stylesAttribute->value;
// split into properties
$definedProperties = (array) explode(';', $definedStyles);
// loop properties
foreach ($definedProperties as $property) {
// validate property
if($property == '') continue;
// split into chunks
$chunks = (array) explode(':', trim($property), 2);
// validate
if(!isset($chunks[1])) continue;
// loop chunks
$properties[$chunks[0]] = trim($chunks[1]);
}
}
// add new properties into the list
foreach ($originalProperties as $key => $value) {
$properties[$key] = $value;
}
// build string
$propertyChunks = array();
// build chunks
foreach ($properties as $key => $values) {
foreach ((array) $values as $value) {
$propertyChunks[] = $key . ': ' . $value . ';';
}
}
// build properties string
$propertiesString = implode(' ', $propertyChunks);
// set attribute
if($propertiesString != '') $element->setAttribute(
'style', $propertiesString
);
}
// remove placeholder
$element->removeAttribute(
'data-css-to-inline-styles-original-styles'
);
}
}
// should we output XHTML?
if ($outputXHTML) {
// set formating
$document->formatOutput = true;
// get the HTML as XML
$html = $document->saveXML(null, LIBXML_NOEMPTYTAG);
// get start of the XML-declaration
$startPosition = strpos($html, '<?xml');
// valid start position?
if ($startPosition !== false) {
// get end of the xml-declaration
$endPosition = strpos($html, '?>', $startPosition);
// remove the XML-header
$html = ltrim(substr($html, $endPosition + 1));
}
}
// just regular HTML 4.01 as it should be used in newsletters
else {
// get the HTML
$html = $document->saveHTML();
}
// cleanup the HTML if we need to
if($this->cleanup) $html = $this->cleanupHTML($html);
// strip original style tags if we need to
if ($this->stripOriginalStyleTags) {
$html = $this->stripOriginalStyleTags($html);
}
// return
return $html;
}
/**
* Get the encoding to use
*
* @return string
*/
private function getEncoding()
{
return $this->encoding;
}
/**
* Process the loaded CSS
*
* @return void
*/
private function processCSS()
{
// init vars
$css = (string) $this->css;
// remove newlines
$css = str_replace(array("\r", "\n"), '', $css);
// replace double quotes by single quotes
$css = str_replace('"', '\'', $css);
// remove comments
$css = preg_replace('|/\*.*?\*/|', '', $css);
// remove spaces
$css = preg_replace('/\s\s+/', ' ', $css);
// rules are splitted by }
$rules = (array) explode('}', $css);
// init var
$i = 1;
// loop rules
foreach ($rules as $rule) {
// split into chunks
$chunks = explode('{', $rule);
// invalid rule?
if(!isset($chunks[1])) continue;
// set the selectors
$selectors = trim($chunks[0]);
// get cssProperties
$cssProperties = trim($chunks[1]);
// split multiple selectors
$selectors = (array) explode(',', $selectors);
// loop selectors
foreach ($selectors as $selector) {
// cleanup
$selector = trim($selector);
// build an array for each selector
$ruleSet = array();
// store selector
$ruleSet['selector'] = $selector;
// process the properties
$ruleSet['properties'] = $this->processCSSProperties(
$cssProperties
);
// calculate specifity
$ruleSet['specifity'] = $this->calculateCSSSpecifity(
$selector
) + $i;
// add into global rules
$this->cssRules[] = $ruleSet;
}
// increment
$i++;
}
// sort based on specifity
if (!empty($this->cssRules)) {
usort($this->cssRules, array(__CLASS__, 'sortOnSpecifity'));
}
}
/**
* Process the CSS-properties
*
* @return array
* @param string $propertyString The CSS-properties.
*/
private function processCSSProperties($propertyString)
{
// split into chunks
$properties = (array) explode(';', $propertyString);
// init var
$pairs = array();
// loop properties
foreach ($properties as $property) {
// split into chunks
$chunks = (array) explode(':', $property, 2);
// validate
if(!isset($chunks[1])) continue;
// cleanup
$chunks[0] = trim($chunks[0]);
$chunks[1] = trim($chunks[1]);
// add to pairs array
if(!isset($pairs[$chunks[0]]) ||
!in_array($chunks[1], $pairs[$chunks[0]])) {
$pairs[$chunks[0]][] = $chunks[1];
}
}
// sort the pairs
ksort($pairs);
// return
return $pairs;
}
/**
* Should the IDs and classes be removed?
*
* @return void
* @param bool[optional] $on Should we enable cleanup?
*/
public function setCleanup($on = true)
{
$this->cleanup = (bool) $on;
}
/**
* Set CSS to use
*
* @return void
* @param string $css The CSS to use.
*/
public function setCSS($css)
{
$this->css = (string) $css;
}
/**
* Set the encoding to use with the DOMDocument
*
* @return void
* @param string $encoding The encoding to use.
*/
public function setEncoding($encoding)
{
$this->encoding = (string) $encoding;
}
/**
* Set HTML to process
*
* @return void
* @param string $html The HTML to process.
*/
public function setHTML($html)
{
$this->html = (string) $html;
}
/**
* Set use of inline styles block
* If this is enabled the class will use the style-block in the HTML.
*
* @return void
* @param bool[optional] $on Should we process inline styles?
*/
public function setUseInlineStylesBlock($on = true)
{
$this->useInlineStylesBlock = (bool) $on;
}
/**
* Set strip original style tags
* If this is enabled the class will remove all style tags in the HTML.
*
* @return void
* @param bool[optional] $onShould we process inline styles?
*/
public function setStripOriginalStyleTags($on = true)
{
$this->stripOriginalStyleTags = (bool) $on;
}
/**
* Strip style tags into the generated HTML
*
* @return string
* @param string $html The HTML to strip style tags.
*/
private function stripOriginalStyleTags($html)
{
return preg_replace('|<style(.*)>(.*)</style>|isU', '', $html);
}
/**
* Sort an array on the specifity element
*
* @return int
* @param array $e1 The first element.
* @param array $e2 The second element.
*/
private static function sortOnSpecifity($e1, $e2)
{
// validate
if(!isset($e1['specifity']) || !isset($e2['specifity'])) return 0;
// lower
if($e1['specifity'] < $e2['specifity']) return -1;
// higher
if($e1['specifity'] > $e2['specifity']) return 1;
// fallback
return 0;
}
}