class JSMinPlus in Advanced CSS/JS Aggregation 7

Hierarchy

• class \JSMinPlus

File

advagg_js_compress/jsminplus.inc, line 174

class JSMinPlus {
  private $parser;
  private $reserved = array(
    'break',
    'case',
    'catch',
    'continue',
    'default',
    'delete',
    'do',
    'else',
    'finally',
    'for',
    'function',
    'if',
    'in',
    'instanceof',
    'new',
    'return',
    'switch',
    'this',
    'throw',
    'try',
    'typeof',
    'var',
    'void',
    'while',
    'with',
    // Words reserved for future use
    'abstract',
    'boolean',
    'byte',
    'char',
    'class',
    'const',
    'debugger',
    'double',
    'enum',
    'export',
    'extends',
    'final',
    'float',
    'goto',
    'implements',
    'import',
    'int',
    'interface',
    'long',
    'native',
    'package',
    'private',
    'protected',
    'public',
    'short',
    'static',
    'super',
    'synchronized',
    'throws',
    'transient',
    'volatile',
    // These are not reserved, but should be taken into account
    // in isValidIdentifier (See jslint source code)
    'arguments',
    'eval',
    'true',
    'false',
    'Infinity',
    'NaN',
    'null',
    'undefined',
  );
  private function __construct() {
    $this->parser = new JSParser($this);
  }
  public static function minify($js, $filename = '') {
    static $instance;

    // this is a singleton
    if (!$instance) {
      $instance = new JSMinPlus();
    }
    return $instance
      ->min($js, $filename);
  }
  private function min($js, $filename) {
    try {
      $n = $this->parser
        ->parse($js, $filename, 1);
      return $this
        ->parseTree($n);
    } catch (Exception $e) {
      echo $e
        ->getMessage() . "\n";
    }
    return false;
  }
  public function parseTree($n, $noBlockGrouping = false) {
    $s = '';
    switch ($n->type) {
      case JS_MINIFIED:
        $s = $n->value;
        break;
      case JS_SCRIPT:

        // we do nothing yet with funDecls or varDecls
        $noBlockGrouping = true;

      // FALL THROUGH
      case JS_BLOCK:
        $childs = $n->treeNodes;
        $lastType = 0;
        for ($c = 0, $i = 0, $j = count($childs); $i < $j; $i++) {
          $type = $childs[$i]->type;
          $t = $this
            ->parseTree($childs[$i]);
          if (strlen($t)) {
            if ($c) {
              $s = rtrim($s, ';');
              if ($type == KEYWORD_FUNCTION && $childs[$i]->functionForm == DECLARED_FORM) {

                // put declared functions on a new line
                $s .= "\n";
              }
              elseif ($type == KEYWORD_VAR && $type == $lastType) {

                // mutiple var-statements can go into one
                $t = ',' . substr($t, 4);
              }
              else {

                // add terminator
                $s .= ';';
              }
            }
            $s .= $t;
            $c++;
            $lastType = $type;
          }
        }
        if ($c > 1 && !$noBlockGrouping) {
          $s = '{' . $s . '}';
        }
        break;
      case KEYWORD_FUNCTION:
        $s .= 'function' . ($n->name ? ' ' . $n->name : '') . '(';
        $params = $n->params;
        for ($i = 0, $j = count($params); $i < $j; $i++) {
          $s .= ($i ? ',' : '') . $params[$i];
        }
        $s .= '){' . $this
          ->parseTree($n->body, true) . '}';
        break;
      case KEYWORD_IF:
        $s = 'if(' . $this
          ->parseTree($n->condition) . ')';
        $thenPart = $this
          ->parseTree($n->thenPart);
        $elsePart = $n->elsePart ? $this
          ->parseTree($n->elsePart) : null;

        // empty if-statement
        if ($thenPart == '') {
          $thenPart = ';';
        }
        if ($elsePart) {

          // be carefull and always make a block out of the thenPart; could be more optimized but is a lot of trouble
          if ($thenPart != ';' && $thenPart[0] != '{') {
            $thenPart = '{' . $thenPart . '}';
          }
          $s .= $thenPart . 'else';

          // we could check for more, but that hardly ever applies so go for performance
          if ($elsePart[0] != '{') {
            $s .= ' ';
          }
          $s .= $elsePart;
        }
        else {
          $s .= $thenPart;
        }
        break;
      case KEYWORD_SWITCH:
        $s = 'switch(' . $this
          ->parseTree($n->discriminant) . '){';
        $cases = $n->cases;
        for ($i = 0, $j = count($cases); $i < $j; $i++) {
          $case = $cases[$i];
          if ($case->type == KEYWORD_CASE) {
            $s .= 'case' . ($case->caseLabel->type != TOKEN_STRING ? ' ' : '') . $this
              ->parseTree($case->caseLabel) . ':';
          }
          else {
            $s .= 'default:';
          }
          $statement = $this
            ->parseTree($case->statements, true);
          if ($statement) {
            $s .= $statement;

            // no terminator for last statement
            if ($i + 1 < $j) {
              $s .= ';';
            }
          }
        }
        $s .= '}';
        break;
      case KEYWORD_FOR:
        $s = 'for(' . ($n->setup ? $this
          ->parseTree($n->setup) : '') . ';' . ($n->condition ? $this
          ->parseTree($n->condition) : '') . ';' . ($n->update ? $this
          ->parseTree($n->update) : '') . ')';
        $body = $this
          ->parseTree($n->body);
        if ($body == '') {
          $body = ';';
        }
        $s .= $body;
        break;
      case KEYWORD_WHILE:
        $s = 'while(' . $this
          ->parseTree($n->condition) . ')';
        $body = $this
          ->parseTree($n->body);
        if ($body == '') {
          $body = ';';
        }
        $s .= $body;
        break;
      case JS_FOR_IN:
        $s = 'for(' . ($n->varDecl ? $this
          ->parseTree($n->varDecl) : $this
          ->parseTree($n->iterator)) . ' in ' . $this
          ->parseTree($n->object) . ')';
        $body = $this
          ->parseTree($n->body);
        if ($body == '') {
          $body = ';';
        }
        $s .= $body;
        break;
      case KEYWORD_DO:
        $s = 'do{' . $this
          ->parseTree($n->body, true) . '}while(' . $this
          ->parseTree($n->condition) . ')';
        break;
      case KEYWORD_BREAK:
      case KEYWORD_CONTINUE:
        $s = $n->value . ($n->label ? ' ' . $n->label : '');
        break;
      case KEYWORD_TRY:
        $s = 'try{' . $this
          ->parseTree($n->tryBlock, true) . '}';
        $catchClauses = $n->catchClauses;
        for ($i = 0, $j = count($catchClauses); $i < $j; $i++) {
          $t = $catchClauses[$i];
          $s .= 'catch(' . $t->varName . ($t->guard ? ' if ' . $this
            ->parseTree($t->guard) : '') . '){' . $this
            ->parseTree($t->block, true) . '}';
        }
        if ($n->finallyBlock) {
          $s .= 'finally{' . $this
            ->parseTree($n->finallyBlock, true) . '}';
        }
        break;
      case KEYWORD_THROW:
      case KEYWORD_RETURN:
        $s = $n->type;
        if ($n->value) {
          $t = $this
            ->parseTree($n->value);
          if (strlen($t)) {
            if ($this
              ->isWordChar($t[0]) || $t[0] == '\\') {
              $s .= ' ';
            }
            $s .= $t;
          }
        }
        break;
      case KEYWORD_WITH:
        $s = 'with(' . $this
          ->parseTree($n->object) . ')' . $this
          ->parseTree($n->body);
        break;
      case KEYWORD_VAR:
      case KEYWORD_CONST:
        $s = $n->value . ' ';
        $childs = $n->treeNodes;
        for ($i = 0, $j = count($childs); $i < $j; $i++) {
          $t = $childs[$i];
          $s .= ($i ? ',' : '') . $t->name;
          $u = $t->initializer;
          if ($u) {
            $s .= '=' . $this
              ->parseTree($u);
          }
        }
        break;
      case KEYWORD_IN:
      case KEYWORD_INSTANCEOF:
        $left = $this
          ->parseTree($n->treeNodes[0]);
        $right = $this
          ->parseTree($n->treeNodes[1]);
        $s = $left;
        if ($this
          ->isWordChar(substr($left, -1))) {
          $s .= ' ';
        }
        $s .= $n->type;
        if ($this
          ->isWordChar($right[0]) || $right[0] == '\\') {
          $s .= ' ';
        }
        $s .= $right;
        break;
      case KEYWORD_DELETE:
      case KEYWORD_TYPEOF:
        $right = $this
          ->parseTree($n->treeNodes[0]);
        $s = $n->type;
        if ($this
          ->isWordChar($right[0]) || $right[0] == '\\') {
          $s .= ' ';
        }
        $s .= $right;
        break;
      case KEYWORD_VOID:
        $s = 'void(' . $this
          ->parseTree($n->treeNodes[0]) . ')';
        break;
      case KEYWORD_DEBUGGER:
        throw new Exception('NOT IMPLEMENTED: DEBUGGER');
        break;
      case TOKEN_CONDCOMMENT_START:
      case TOKEN_CONDCOMMENT_END:
        $s = $n->value . ($n->type == TOKEN_CONDCOMMENT_START ? ' ' : '');
        $childs = $n->treeNodes;
        for ($i = 0, $j = count($childs); $i < $j; $i++) {
          $s .= $this
            ->parseTree($childs[$i]);
        }
        break;
      case OP_SEMICOLON:
        if ($expression = $n->expression) {
          $s = $this
            ->parseTree($expression);
        }
        break;
      case JS_LABEL:
        $s = $n->label . ':' . $this
          ->parseTree($n->statement);
        break;
      case OP_COMMA:
        $childs = $n->treeNodes;
        for ($i = 0, $j = count($childs); $i < $j; $i++) {
          $s .= ($i ? ',' : '') . $this
            ->parseTree($childs[$i]);
        }
        break;
      case OP_ASSIGN:
        $s = $this
          ->parseTree($n->treeNodes[0]) . $n->value . $this
          ->parseTree($n->treeNodes[1]);
        break;
      case OP_HOOK:
        $s = $this
          ->parseTree($n->treeNodes[0]) . '?' . $this
          ->parseTree($n->treeNodes[1]) . ':' . $this
          ->parseTree($n->treeNodes[2]);
        break;
      case OP_OR:
      case OP_AND:
      case OP_BITWISE_OR:
      case OP_BITWISE_XOR:
      case OP_BITWISE_AND:
      case OP_EQ:
      case OP_NE:
      case OP_STRICT_EQ:
      case OP_STRICT_NE:
      case OP_LT:
      case OP_LE:
      case OP_GE:
      case OP_GT:
      case OP_LSH:
      case OP_RSH:
      case OP_URSH:
      case OP_MUL:
      case OP_DIV:
      case OP_MOD:
        $s = $this
          ->parseTree($n->treeNodes[0]) . $n->type . $this
          ->parseTree($n->treeNodes[1]);
        break;
      case OP_PLUS:
      case OP_MINUS:
        $left = $this
          ->parseTree($n->treeNodes[0]);
        $right = $this
          ->parseTree($n->treeNodes[1]);
        switch ($n->treeNodes[1]->type) {
          case OP_PLUS:
          case OP_MINUS:
          case OP_INCREMENT:
          case OP_DECREMENT:
          case OP_UNARY_PLUS:
          case OP_UNARY_MINUS:
            $s = $left . $n->type . ' ' . $right;
            break;
          case TOKEN_STRING:

            //combine concatted strings with same quotestyle
            if ($n->type == OP_PLUS && substr($left, -1) == $right[0]) {
              $s = substr($left, 0, -1) . substr($right, 1);
              break;
            }

          // FALL THROUGH
          default:
            $s = $left . $n->type . $right;
        }
        break;
      case OP_NOT:
      case OP_BITWISE_NOT:
      case OP_UNARY_PLUS:
      case OP_UNARY_MINUS:
        $s = $n->value . $this
          ->parseTree($n->treeNodes[0]);
        break;
      case OP_INCREMENT:
      case OP_DECREMENT:
        if ($n->postfix) {
          $s = $this
            ->parseTree($n->treeNodes[0]) . $n->value;
        }
        else {
          $s = $n->value . $this
            ->parseTree($n->treeNodes[0]);
        }
        break;
      case OP_DOT:
        $s = $this
          ->parseTree($n->treeNodes[0]) . '.' . $this
          ->parseTree($n->treeNodes[1]);
        break;
      case JS_INDEX:
        $s = $this
          ->parseTree($n->treeNodes[0]);

        // See if we can replace named index with a dot saving 3 bytes
        if ($n->treeNodes[0]->type == TOKEN_IDENTIFIER && $n->treeNodes[1]->type == TOKEN_STRING && $this
          ->isValidIdentifier(substr($n->treeNodes[1]->value, 1, -1))) {
          $s .= '.' . substr($n->treeNodes[1]->value, 1, -1);
        }
        else {
          $s .= '[' . $this
            ->parseTree($n->treeNodes[1]) . ']';
        }
        break;
      case JS_LIST:
        $childs = $n->treeNodes;
        for ($i = 0, $j = count($childs); $i < $j; $i++) {
          $s .= ($i ? ',' : '') . $this
            ->parseTree($childs[$i]);
        }
        break;
      case JS_CALL:
        $s = $this
          ->parseTree($n->treeNodes[0]) . '(' . $this
          ->parseTree($n->treeNodes[1]) . ')';
        break;
      case KEYWORD_NEW:
      case JS_NEW_WITH_ARGS:
        $s = 'new ' . $this
          ->parseTree($n->treeNodes[0]) . '(' . ($n->type == JS_NEW_WITH_ARGS ? $this
          ->parseTree($n->treeNodes[1]) : '') . ')';
        break;
      case JS_ARRAY_INIT:
        $s = '[';
        $childs = $n->treeNodes;
        for ($i = 0, $j = count($childs); $i < $j; $i++) {
          $s .= ($i ? ',' : '') . $this
            ->parseTree($childs[$i]);
        }
        $s .= ']';
        break;
      case JS_OBJECT_INIT:
        $s = '{';
        $childs = $n->treeNodes;
        for ($i = 0, $j = count($childs); $i < $j; $i++) {
          $t = $childs[$i];
          if ($i) {
            $s .= ',';
          }
          if ($t->type == JS_PROPERTY_INIT) {

            // Ditch the quotes when the index is a valid identifier
            if ($t->treeNodes[0]->type == TOKEN_STRING && $this
              ->isValidIdentifier(substr($t->treeNodes[0]->value, 1, -1))) {
              $s .= substr($t->treeNodes[0]->value, 1, -1);
            }
            else {
              $s .= $t->treeNodes[0]->value;
            }
            $s .= ':' . $this
              ->parseTree($t->treeNodes[1]);
          }
          else {
            $s .= $t->type == JS_GETTER ? 'get' : 'set';
            $s .= ' ' . $t->name . '(';
            $params = $t->params;
            for ($i = 0, $j = count($params); $i < $j; $i++) {
              $s .= ($i ? ',' : '') . $params[$i];
            }
            $s .= '){' . $this
              ->parseTree($t->body, true) . '}';
          }
        }
        $s .= '}';
        break;
      case TOKEN_NUMBER:
        $s = $n->value;
        if (preg_match('/^([1-9]+)(0{3,})$/', $s, $m)) {
          $s = $m[1] . 'e' . strlen($m[2]);
        }
        break;
      case KEYWORD_NULL:
      case KEYWORD_THIS:
      case KEYWORD_TRUE:
      case KEYWORD_FALSE:
      case TOKEN_IDENTIFIER:
      case TOKEN_STRING:
      case TOKEN_REGEXP:
        $s = $n->value;
        break;
      case JS_GROUP:
        if (in_array($n->treeNodes[0]->type, array(
          JS_ARRAY_INIT,
          JS_OBJECT_INIT,
          JS_GROUP,
          TOKEN_NUMBER,
          TOKEN_STRING,
          TOKEN_REGEXP,
          TOKEN_IDENTIFIER,
          KEYWORD_NULL,
          KEYWORD_THIS,
          KEYWORD_TRUE,
          KEYWORD_FALSE,
        ))) {
          $s = $this
            ->parseTree($n->treeNodes[0]);
        }
        else {
          $s = '(' . $this
            ->parseTree($n->treeNodes[0]) . ')';
        }
        break;
      default:
        throw new Exception('UNKNOWN TOKEN TYPE: ' . $n->type);
    }
    return $s;
  }
  private function isValidIdentifier($string) {
    return preg_match('/^[a-zA-Z_][a-zA-Z0-9_]*$/', $string) && !in_array($string, $this->reserved);
  }
  private function isWordChar($char) {
    return $char == '_' || $char == '$' || ctype_alnum($char);
  }

}

Members

Name	Modifiers	Type	Description	Overrides
JSMinPlus::$parser	private	property
JSMinPlus::$reserved	private	property
JSMinPlus::isValidIdentifier	private	function
JSMinPlus::isWordChar	private	function
JSMinPlus::min	private	function
JSMinPlus::minify	public static	function
JSMinPlus::parseTree	public	function
JSMinPlus::__construct	private	function