@param mixed $value

@return bool
513025
private static function boolval($value)
    {
        if (is_numeric($value)) {
            $value = (float) $value > 0;
        } elseif (is_string($value)) {
            $value = 'false' !== $value;
        }

        return is_bool($value) ? $value : false;
    }
1124362
public function isValid($value)
    {
        if (!is_string($value) && !is_int($value) && !is_float($value)) {
            $this->_error(self::INVALID);
            return false;
        }

        $this->_setValue($value);

        if ('' === $value) {
            $this->_error(self::STRING_EMPTY);
            return false;
        }

        if (null === self::$_filter) {
            /**
             * @see Zend_Filter_Alnum
             */
            // require_once 'Zend/Filter/Alnum.php';
            self::$_filter = new Zend_Filter_Alnum();
        }

        self::$_filter->allowWhiteSpace = $this->allowWhiteSpace;

        if ($value != self::$_filter->filter($value)) {
            $this->_error(self::NOT_ALNUM);
            return false;
        }

        return true;
    }
887708
public function server($value)
    {
        if (!isset($this->server[$value])) {
            return false;
        } else {
            return $this->server[$value];
        }
    }
264066
public function validate($value)
    {
        foreach ($this->items as $item) {
            if ($item->validate($value)) {
                return true;
            }
        }

        return false;
    }
1229004
public function isValid($value)
    {
        try {
            if (null === \json_decode($value, true)) {
                return $this->_error(self::INVALID);
            }
        } catch (\Exception $e) {
            return $this->_error(self::INVALID);
        }
        return true;
    }
1369914
public function isValid($value)
    {
        if (!is_string($value)) {
            $this->_error(self::INVALID);
            return false;
        }

        $this->_setValue($value);
        $result = Zend_Uri::check($value);
        if ($result !== true) {
            $this->_error(self::NOT_VALID);
            return false;
        }

        return true;
    }
856002
public static function datetime($value): bool
    {
        if ($value instanceof \DateTime) {
            return true;
        } elseif (strtotime($value) !== false) {
            return true;
        }

        return false;
    }
836559
private function check($value) {

		if(true === is_string($value)) {
			
			@json_decode($value);

	 		return true === (json_last_error() == JSON_ERROR_NONE);
	 	}

	 	return false;
	}
920484
public function isValid($value)
    {
        $result = filter_var($value, FILTER_VALIDATE_EMAIL);
        if (!$result) {
            $this->addMessage('email');
        }
        return (boolean) $result;
    }
1296136
public function isValid($value)
    {
        $this->_setValue((string) $value);

        if (is_string($value)
            && (('' === $value) 
            || preg_match('/^\s+$/s', $value))
        ) {
            $this->_error();
            return false;
        } elseif (!is_string($value) && empty($value)) {
            $this->_error();
            return false;
        }

        return true;
    }
221154
public static function isBooleanValue($value): bool
    {
        return is_bool($value) || self::isBooleanStringValue($value) || self::isBooleanNumericValue($value);
    }
1207604
public function isValid($value)
    {
        if (!is_string($value) && !is_int($value) && !is_float($value)) {
            $this->_error(self::INVALID);
            return false;
        }

        $this->_setValue($value);

        $status = @preg_match($this->_pattern, $value);
        if (false === $status) {
            $this->_error(self::ERROROUS);
            return false;
        }

        if (!$status) {
            $this->_error(self::NOT_MATCH);
            return false;
        }

        return true;
    }
1091713
public function isValid($value)
    {
        $valid = true;
        $this->setValue($value);

        $result = $this->query($value);
        if ($result) {
            $valid = false;
            $this->error(self::ERROR_RECORD_FOUND);
        }

        return $valid;
    }
132530
public function isValid($value)
    {
        if (!is_null($value) && !is_string($value) && !is_int($value) && !is_float($value) &&
            !is_bool($value) && !is_array($value)) {
            $this->_error(self::INVALID);
            return false;
        }
        if (is_string($value) && (('' === $value) || preg_match('/^\s+$/s', $value))) {
            $this->_error(self::INVALID);
            return false;
        } elseif (is_int($value) && (0 === $value)) {
            return true;
        } elseif (!is_string($value) && empty($value)) {
            $this->_error(self::INVALID);
            return false;
        }
        return true;
    }
785074
public function isValid ($value)
    {
        if (!is_numeric($value)) {
            $this->error(self::INVALID);
            return false;
        }

        if (!preg_match('/^-?[0-9]+([.,][0-9]+)?$/', $value)) {
            $this->error(self::INVALID);
            return false;
        }

        return true;
    }
855694
public function isValid($value)
    {
        foreach ($this as $type) {
            if ($type->isValid($value)) {
                return true;
            }
        }

        return false;
    }
975544
public static function has($value)
    {
        if ($value instanceof static && get_class($value) === get_called_class()) {
            return true;
        }
        $class = get_called_class();
        $constants = static::detectConstants($class);
        return in_array($value, $constants, true);
    }