private function _ParseExpression()
{
$arrTokens = Toolset_Tokenizer::Tokanize($this->strInFix);
if (!isset($arrTokens)) {
throw new Exception("Unable to tokanize the expression!");
}
if (count($arrTokens) <= 0) {
throw new Exception("Unable to tokanize the expression!");
}
//print_r($arrTokens);
$myarrPostFix = $this->_InFixToPostFix($arrTokens);
if (!isset($myarrPostFix)) {
throw new Exception("Unable to convert the expression to postfix form!");
}
if (count($myarrPostFix) <= 0) {
throw new Exception("Unable to convert the expression to postfix form!");
}
//print_r($myarrPostFix);
return $myarrPostFix;
}
/**
* Uses the Toolset_Tokenizer to break down the expression, replace problematic operators by their text-only
* equivalents and glue the expression back together.
*
* Side-effects: Loses custom whitespace characters. All operators (except parentheses) will be surrounded by spaces
* while everywhere else the whitespace characters will be trimmed.
*
* Note: If an invalid expression is provided, it doesn't do anything with it.
*
* @param string $expression Condition expression.
* @return string Equivalent expression but without <, <=, etc.
* @since 2.0
*/
protected function transform_operators_to_text_equivalents($expression)
{
try {
// The expression may come directly from parse_str() which may add backslashes to quotes. The tokenizer
// wouldn't survive that.
$expression = stripslashes($expression);
$toolset_bootstrap = Toolset_Common_Bootstrap::getInstance();
$toolset_bootstrap->register_parser();
$tokenizer = new Toolset_Tokenizer();
$tokens = $tokenizer->Tokanize($expression);
$token_value_replacements = array('<' => 'lt', '>' => 'gt', '<=' => 'lte', '>=' => 'gte', '<>' => 'ne', '=' => 'eq');
$result = '';
foreach ($tokens as $token) {
if ($token->isCompOp) {
$token->val = wpcf_getarr($token_value_replacements, $token->val, $token->val);
}
if ($token->isCompOp || $token->isArithmeticOp || $token->isLogicOp) {
$result .= ' ' . $token->val . ' ';
} else {
if ($token->isStringLiteral) {
$result .= '\'' . $token->val . '\'';
} else {
$result .= $token->val;
}
}
}
return $result;
} catch (Exception $e) {
// Most probably we were unable to tokenize the expression. We give up.
return $expression;
}
}
