Check is value valid.

@param string $value
@return bool
770299
public function isValueValid($value) {
		return $value instanceof Type\CreativeWorkType || $value instanceof Type\ProductType || $value instanceof DataType\URLType;
	}
333365
public function isValid($value)
    {
        $this->_setValue($value);

        if (!$value || !is_string($value) && !is_int($value) && !is_float($value)) {
            $this->_error(self::INVALID_PRICE);
            return false;
        }

        if (false === $this->_options['negative'] && '-' === $value[0]) {
            $this->_error(self::PRICE_NEGATIVE, $value);
            return false;
        }

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

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

        return true;
    }
111836
public function isValueValid($value) {
		return $value instanceof Type\Place || $value instanceof Type\PostalAddress || $value instanceof DataType\TextType;
	}
233555
public function isValid($value) : bool
    {
        if ($value === null && $this->nullable) {
            return true;
        }

        return is_array($value);
    }
939899
public function isValueValid($value) {
		return $value instanceof DataType\NumberType || $value instanceof Type\QuantitativeValueType || $value instanceof DataType\TextType;
	}
1275350
public function isValueValid($value) {
		return $value instanceof Type\GeoShape || $value instanceof Type\Place || $value instanceof DataType\TextType;
	}
871316
public function isValid($value)
    {
        $valueString = (string) $value;

        $this->_setValue($valueString);

        // Check input against IP address schema
        if ($this->_ipValidator->setTranslator($this->getTranslator())->isValid($valueString)) {
            if (!($this->_allow & self::ALLOW_IP)) {
                $this->_error(self::IP_ADDRESS_NOT_ALLOWED);
                return false;
            } else{
                return true;
            }
        }

        // Check input against DNS hostname schema
        $domainParts = explode('.', $valueString);
        if ((count($domainParts) > 1) && (strlen($valueString) >= 4) && (strlen($valueString) <= 254)) {
            $status = false;

            do {
                // First check TLD
                if (preg_match('/([a-z]{2,10})$/i', end($domainParts), $matches)) {

                    reset($domainParts);

                    // Hostname characters are: *(label dot)(label dot label); max 254 chars
                    // label: id-prefix [*ldh{61} id-prefix]; max 63 chars
                    // id-prefix: alpha / digit
                    // ldh: alpha / digit / dash

                    // Match TLD against known list
                    $this->_tld = strtolower($matches[1]);
                    if ($this->_validateTld) {
                        if (!in_array($this->_tld, $this->_validTlds)) {
                            $this->_error(self::UNKNOWN_TLD);
                            $status = false;
                            break;
                        }
                    }

                    /**
                     * Match against IDN hostnames
                     *
                     * @see Zend_Validate_Hostname_Interface
                     */
                    $labelChars = 'a-z0-9';
                    $utf8 = false;
                    $classFile = 'Zend/Validate/Hostname/' . ucfirst($this->_tld) . '.php';
                    if ($this->_validateIdn) {
                        if (Zend_Loader::isReadable($classFile)) {

                            // Load additional characters
                            $className = 'Zend_Validate_Hostname_' . ucfirst($this->_tld);
                            Zend_Loader::loadClass($className);
                            $labelChars .= call_user_func(array($className, 'getCharacters'));
                            $utf8 = true;
                        }
                    }

                    // Keep label regex short to avoid issues with long patterns when matching IDN hostnames
                    $regexLabel = '/^[' . $labelChars . '\x2d]{1,63}$/i';
                    if ($utf8) {
                        $regexLabel .= 'u';
                    }

                    // Check each hostname part
                    $valid = true;
                    foreach ($domainParts as $domainPart) {

                        // Check dash (-) does not start, end or appear in 3rd and 4th positions
                        if (strpos($domainPart, '-') === 0 
                            || (strlen($domainPart) > 2 && strpos($domainPart, '-', 2) == 2 && strpos($domainPart, '-', 3) == 3) 
                            || strrpos($domainPart, '-') === strlen($domainPart) - 1
                        ) {

                            $this->_error(self::INVALID_DASH);
                            $status = false;
                            break 2;
                        }

                        // Check each domain part
                        $status = @preg_match($regexLabel, $domainPart);
                        if ($status === false) {
                            /**
                             * Regex error
                             *
                             * @see Zend_Validate_Exception
                             */
                            include_once 'Zend/Validate/Exception.php';
                            throw new Zend_Validate_Exception('Internal error: DNS validation failed');
                        } elseif ($status === 0) {
                            $valid = false;
                        }
                    }

                    // If all labels didn't match, the hostname is invalid
                    if (!$valid) {
                        $this->_error(self::INVALID_HOSTNAME_SCHEMA);
                        $status = false;
                    }

                } else {
                    // Hostname not long enough
                    $this->_error(self::UNDECIPHERABLE_TLD);
                    $status = false;
                }
            } while (false);

            // If the input passes as an Internet domain name, and domain names are allowed, then the hostname
            // passes validation
            if ($status && ($this->_allow & self::ALLOW_DNS)) {
                return true;
            }
        } else {
            $this->_error(self::INVALID_HOSTNAME);
        }

        // Check input against local network name schema; last chance to pass validation
        $regexLocal = '/^(([a-zA-Z0-9\x2d]{1,63}\x2e)*[a-zA-Z0-9\x2d]{1,63}){1,254}$/';
        $status = @preg_match($regexLocal, $valueString);
        if (false === $status) {
            /**
             * Regex error
             *
             * @see Zend_Validate_Exception
             */
            include_once 'Zend/Validate/Exception.php';
            throw new Zend_Validate_Exception('Internal error: local network name validation failed');
        }

        // If the input passes as a local network name, and local network names are allowed, then the
        // hostname passes validation
        $allowLocal = $this->_allow & self::ALLOW_LOCAL;
        if ($status && $allowLocal) {
            return true;
        }

        // If the input does not pass as a local network name, add a message
        if (!$status) {
            $this->_error(self::INVALID_LOCAL_NAME);
        }

        // If local network names are not allowed, add a message
        if ($status && !$allowLocal) {
            $this->_error(self::LOCAL_NAME_NOT_ALLOWED);
        }

        return false;
    }
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 $valid;
    }
634797
public function isValueValid($value) {
		return $value instanceof Type\DistanceType || $value instanceof DataType\NumberType || $value instanceof DataType\TextType;
	}
261786
public function isValueValid($value) {
		return $value instanceof Type\QualitativeValue || $value instanceof DataType\TextType || $value instanceof DataType\URLType;
	}
1297774
public static function isValid($value)
    {
        if ($value instanceof \DateTime)
            return true;
        try {
            new static($value);
            return !is_null($value);
        } catch (\Exception $e) {
            return false;
        }
    }
253515
public function isValueValid($value) {
		return $value instanceof Type\AlignmentObject || $value instanceof Type\Course || $value instanceof DataType\TextType;
	}
1335174
public function isValid($value)
    {
        $valueString = (string) $value;

        $this->_setValue($valueString);

        if ((ip2long($valueString) === false) || (long2ip(ip2long($valueString)) !== $valueString)) {
            if (!function_exists('inet_pton')) {
                $this->_error();
                return false;
            } else if ((@inet_pton($value) === false) ||(inet_ntop(@inet_pton($value)) !== $valueString)) {
                $this->_error();
                return false;
            }
        }

        return true;
    }
879189
public function validateValue($value)
    {
        // make sure string length is limited to avoid DOS attacks
        $valid = is_string($value) && strlen($value) <= 254 && (preg_match($this->pattern, $value) || $this->allowName && preg_match($this->fullPattern, $value));
        return $valid;
    }
1247203
public function isValueValid($value) {
		return $value instanceof Type\Menu || $value instanceof DataType\TextType || $value instanceof DataType\URLType;
	}
655628
protected function checkValidity($value) : bool
    {
        if ('' === $value) {
            return true;
        }
        $date = date_create($value);
        if (false === $date) {
            return false;
        }
        return true;
    }
63333
public function isValueValid($value) {
		return $value instanceof Type\DataFeedItem || $value instanceof DataType\TextType || $value instanceof Type\Thing;
	}