polyfill.module

<?php
/**
 * Implements hook_init().
 * Adds modernizr.min.js
 */
function polyfill_init() {
  drupal_add_css(drupal_get_path('module', 'polyfill') . '/modernizr.js');
}

function polyfill_flush_caches() {
  file_unmanaged_delete_recursive(drupal_realpath(file_default_scheme() . '://polyfill', TRUE));
}

/**
 * Implements hook_css_alter().
 * Searches for files with .less ending in css files array
 * and applies lessc.php and polyfills.
 */
function polyfill_css_alter(&$css) {
  if (variable_get('preprocess_css') != 0) {
    return;
  }
  $path = file_default_scheme() . '://polyfill';
  $files_keys = array_keys($css);
  $files_values = array_values($css);
  foreach ($files_keys as $key => $input_file) {
    if (drupal_substr($input_file, -5) == '.less') {
      $css_path = $path . '/' . dirname($input_file);

      if (!is_dir($css_path)) {
        drupal_mkdir($css_path, 0777, TRUE);
      }

      $output_file = $css_path . '/' . basename($input_file, '.less');
      if (drupal_substr($output_file, -4) != '.css') {
        $output_file .= '.css';
      }

      if (!file_exists($output_file) || ( filemtime($input_file) > filemtime($output_file) )) {
        require_once('sites/all/libraries/cssparser/CSSParser.php');
        require_once('sites/all/libraries/lessphp/lessc.inc.php');
        $contents = drupal_load_stylesheet($input_file, FALSE);
        // Build the base URL of this CSS file: start with the full URL.
        $css_base_url = file_create_url($input_file);
        // Move to the parent.
        $css_base_url = substr($css_base_url, 0, strrpos($css_base_url, '/'));
        // Simplify to a relative URL if the stylesheet URL starts with the
        // base URL of the website.
        if (substr($css_base_url, 0, strlen($GLOBALS['base_root'])) == $GLOBALS['base_root']) {
          $css_base_url = substr($css_base_url, strlen($GLOBALS['base_root']));
        }

        _drupal_build_css_path(NULL, $css_base_url . '/');
        // Prefix all paths within this CSS file, ignoring external and absolute paths.
        $contents = preg_replace_callback('/url\(\s*[\'"]?(?![a-z]+:|\/+)([^\'")]+)[\'"]?\s*\)/i', '_drupal_build_css_path', $contents);
        $less = new lessc();  
        $contents = $less->parse($contents);
        $parser = new CSSParser($contents);
        $css = $parser->parse();
        $processors = module_invoke_all('polyfill_processors');
        foreach ($css->getAllDeclarationBlocks() as $block) {
          foreach ($processors as $property => $callbacks) {
            foreach ($block->getRules($property) as $rule) {
              foreach ($callbacks as $callback) {
                foreach (call_user_func($callback, $rule) as $newrule) {
                  $block->addRule($newrule);
                }
              }
            }
          }
        }
        $contents = $css->__toString();
        file_save_data($contents, $output_file, FILE_EXISTS_REPLACE);
      }

      if (file_exists($output_file)) {
        array_splice($files_keys, $key, 1, $output_file);
        $files_values[$key]['data'] = $output_file;
      }
    }
  }
  $css = array_combine($files_keys, $files_values);
}

/**
 * Mapping of properties and corresponding alteration hooks.
 * Polyfill hooks will be provided with the current selector
 * and an array of properties their values, which is passed
 * by reference to be alterable.
 */
function polyfill_polyfill_processors() {
  return array(
    'border-radius' => array('polyfill_vendor_prefix'),
    'box-shadow' => array('polyfill_vendor_prefix'),
    'transition' => array('polyfill_vendor_prefix'),
    'transform' => array('polyfill_vendor_prefix'),
    'border-image' => array('polyfill_vendor_prefix'),
    'column-count' => array('polyfill_vendor_prefix'),
    'column-gap' => array('polyfill_vendor_prefix'),
  );
}


/**
 * Adds vendor prefixes to all properties which require them.
 */
function polyfill_vendor_prefix($rule) {
  $prefixes = array('-webkit-', '-moz-', '-o-', '-ms-');
  $new = array();
  foreach ($prefixes as $p) {
    $r = new CSSRule($p . $rule->getRule());
    $r->setValue($rule->getValue());
    $new[] = $r;
  }
  return $new;
}

/* ====================================================================== */
/* UNUSED - PORT TO NEW SUBMODULES                                        */
/* ====================================================================== */
function polyfill_box($sel, &$prop) {
  if (in_array('box', $prop['display'])) {
    $prop['display'][] = '-webkit-box';
    $prop['display'][] = '-moz-box';
  }
}

/**
 * Search for linear gradients.
 */
function polyfill_linear_gradient($sel, &$prop) {
  foreach (array_keys($prop) as $p) {
    foreach ($prop[$p] as $v) {
      if (preg_match('/.*(linear-gradient\((.*?)\)).*$/', $v, $matches)) {
        // Basic prefixes
        $prefixes = array('webkit', 'moz', 'ms', 'o');
        foreach ($prefixes as $pre) {
          polyfill_add_rule($p, '-' . $pre . '-' . $matches[0], $prop);
        }
        list($d, $colors) = _polyfill_parse_gradient($v);
        // Webkit syntax
        $dir = array('0', '0', '0', '0');
        $rule = '-webkit-gradient(linear, ';
        if(preg_match('/left/', $d)) {
            $dir[2] = '100%';
        }
        else if(preg_match('/right/', $d)) {
            $dir[0] = '100%';
        }
        if(preg_match('/top/', $d)) {
            $dir[3] = '100%';
        }
        else if(preg_match('/bottom/', $d)) {
            $dir[1] = '100%';
        }
        $rule .= $dir[0] . ' ' . $dir[1] . ', ' . $dir[2] . ' ' . $dir[3];
        foreach ($colors as  $k => $c) {
          if ($k == 0) {
            $rule .= ', from';
          }
          else if($k == (count($colors) - 1)) {
            $rule .= ', to';
          }
          else {
            $rule .= ', color-stop';
          } 
          if ($c['p']) {
            $rule .= '(' . $c['p']/100 . ', ' . $c['c'] . ')';
          }
          else {
            $rule .= '(' . $c['c'] . ')';
          }
        }
        $rule .= ')';
        $rule = str_replace($matches[1], $rule, $matches[0]);
        polyfill_add_rule($p, $rule, $prop);
        // IE Gradient FIXXME!
        $rule = 'progid:DXImageTransform.Microsoft.Gradient(StartColorstr="' . $colors[0]['c'] . '", EndColorStr="' . $colors[count($colors) - 1]['c'] . '")';
        polyfill_add_rule('filter', $rule, $prop); 
        polyfill_add_rule('-ms-filter', $rule, $prop); 
      }
    }
  }
}

function _polyfill_parse_gradient($v) {
  $edirection = '/(?:(?<direction>(?:top\s+|bottom\s+)?(?:right|left)|(?:right\s+|left\s+)?(?:top|bottom)))/';
  $epercent = "(?<percent>[0-9]+)\%";
  $ecolor = "(?<color>\#[a-zA-Z0-9]+)";
  $ecolorstop = "/(?:$ecolor(?:\s*$epercent)?)/";
  $directions = array();
  $colorstops = array();
  $colors = array();
  preg_match_all($edirection, $v, $directions);
  preg_match_all($ecolorstop, $v, $colorstops);
  $direction = (count($directions['direction']) > 0) ? $directions['direction'][0] : FALSE;
  for ($k = 0; $k < count($colorstops['color']); $k++) {
    $colors[] = array(
      'c' => $colorstops['color'][$k],
      'p' => $colorstops['percent'][$k],
    );
  } 
  return array($direction, $colors);
}

/**
 * Adds CSSPIE behavior for CSS3 decorations in IE6-8.
 */
function polyfill_pie($sel, &$prop) {
  $pie = 'url(' . file_create_url(drupal_get_path('module', 'polyfill') . '/PIE.htc') . ')';
  polyfill_add_rule('behavior', $pie, $prop);
  // IE8 doesn't display statically positioned PIE elements
  if (!array_key_exists('position', $prop)) {
    polyfill_add_rule('position', 'relative', $prop);
  }
}