class Emogrifier in HTML Mail 5

Hierarchy

• class \Emogrifier

1 string reference to 'Emogrifier'

htmlmail_admin_settings in ./htmlmail.module

File

emogrifier/emogrifier.php, line 45

CSS to Inline Converter Class

class Emogrifier {
  private $html = '';
  private $css = '';
  private $unprocessableHTMLTags = array(
    'wbr',
  );
  public function __construct($html = '', $css = '') {
    $this->html = $html;
    $this->css = $css;
  }
  public function setHTML($html = '') {
    $this->html = $html;
  }
  public function setCSS($css = '') {
    $this->css = $css;
  }

  // there are some HTML tags that DOMDocument cannot process, and will throw an error if it encounters them.
  // these functions allow you to add/remove them if necessary.
  // it only strips them from the code (does not remove actual nodes).
  public function addUnprocessableHTMLTag($tag) {
    $this->unprocessableHTMLTags[] = $tag;
  }
  public function removeUnprocessableHTMLTag($tag) {
    if (($key = array_search($tag, $this->unprocessableHTMLTags)) !== false) {
      unset($this->unprocessableHTMLTags[$key]);
    }
  }

  // applies the CSS you submit to the html you submit. places the css inline
  public function emogrify() {
    $body = $this->html;

    // process the CSS here, turning the CSS style blocks into inline css
    if (count($this->unprocessableHTMLTags)) {
      $unprocessableHTMLTags = implode('|', $this->unprocessableHTMLTags);
      $body = preg_replace("/<({$unprocessableHTMLTags})[^>]*>/i", '', $body);
    }
    $xmldoc = new DOMDocument();
    $xmldoc->strictErrorChecking = false;
    $xmldoc->formatOutput = true;
    $xmldoc
      ->loadHTML($body);
    $xmldoc
      ->normalizeDocument();
    $xpath = new DOMXPath($xmldoc);

    // get rid of css comment code
    $re_commentCSS = '/\\/\\*.*\\*\\//sU';
    $css = preg_replace($re_commentCSS, '', $this->css);

    // process the CSS file for selectors and definitions
    $re_CSS = '/^\\s*([^{]+){([^}]+)}/mis';
    preg_match_all($re_CSS, $css, $matches);
    foreach ($matches[1] as $key => $selectorString) {

      // if there is a blank definition, skip
      if (!strlen(trim($matches[2][$key]))) {
        continue;
      }

      // split up the selector
      $selectors = explode(',', $selectorString);
      foreach ($selectors as $selector) {

        // don't process pseudo-classes
        if (strpos($selector, ':') !== false) {
          continue;
        }

        // query the body for the xpath selector
        $nodes = $xpath
          ->query($this
          ->translateCSStoXpath(trim($selector)));
        foreach ($nodes as $node) {

          // if it has a style attribute, get it, process it, and append (overwrite) new stuff
          if ($node
            ->hasAttribute('style')) {
            $style = $node
              ->getAttribute('style');

            // break it up into an associative array
            $oldStyleArr = $this
              ->cssStyleDefinitionToArray($node
              ->getAttribute('style'));
            $newStyleArr = $this
              ->cssStyleDefinitionToArray($matches[2][$key]);

            // new styles overwrite the old styles (not technically accurate, but close enough)
            $combinedArr = array_merge($oldStyleArr, $newStyleArr);
            $style = '';
            foreach ($combinedArr as $k => $v) {
              $style .= $k . ':' . $v . ';';
            }
          }
          else {

            // otherwise create a new style
            $style = trim($matches[2][$key]);
          }
          $node
            ->setAttribute('style', $style);
        }
      }
    }

    // This removes styles from your email that contain display:none;. You could comment these out if you want.
    $nodes = $xpath
      ->query('//*[contains(translate(@style," ",""),"display:none;")]');
    foreach ($nodes as $node) {
      $node->parentNode
        ->removeChild($node);
    }
    return $xmldoc
      ->saveHTML();
  }

  // right now we only support CSS 1 selectors, but include CSS2/3 selectors are fully possible.
  // http://plasmasturm.org/log/444/
  private function translateCSStoXpath($css_selector) {

    // returns an Xpath selector
    $search = array(
      '/\\s+>\\s+/',
      // Matches any F element that is a child of an element E.
      '/(\\w+)\\s+\\+\\s+(\\w+)/',
      // Matches any F element that is a child of an element E.
      '/\\s+/',
      // Matches any F element that is a descendant of an E element.
      '/(\\w+)?\\#([\\w\\-]+)/e',
      // Matches id attributes
      '/(\\w+)?\\.([\\w\\-]+)/e',
    );
    $replace = array(
      '/',
      '\\1/following-sibling::*[1]/self::\\2',
      '//',
      "(strlen('\\1') ? '\\1' : '*').'[@id=\"\\2\"]'",
      "(strlen('\\1') ? '\\1' : '*').'[contains(concat(\" \",@class,\" \"),concat(\" \",\"\\2\",\" \"))]'",
    );
    return '//' . preg_replace($search, $replace, trim($css_selector));
  }
  private function cssStyleDefinitionToArray($style) {
    $definitions = explode(';', $style);
    $retArr = array();
    foreach ($definitions as $def) {
      list($key, $value) = explode(':', $def);
      if (empty($key) || empty($value)) {
        continue;
      }
      $retArr[trim($key)] = trim($value);
    }
    return $retArr;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
Emogrifier::$css	private	property
Emogrifier::$html	private	property
Emogrifier::$unprocessableHTMLTags	private	property
Emogrifier::addUnprocessableHTMLTag	public	function
Emogrifier::cssStyleDefinitionToArray	private	function
Emogrifier::emogrify	public	function
Emogrifier::removeUnprocessableHTMLTag	public	function
Emogrifier::setCSS	public	function
Emogrifier::setHTML	public	function
Emogrifier::translateCSStoXpath	private	function
Emogrifier::__construct	public	function