Returns true, if the given value is unique among the groups of the user.

Also returns true, if the given value equals the {@link $allowName}.

@param string $value
@return bool
@see \Zend\Validator\ValidatorInterface::isValid()
322439
public function isValid($value)
    {
        if ($value == $this->allowName) {
            return true;
        }
        
        foreach ($this->getUser()->getGroups() as $group) {
            if ($group->getName() == $value) {
                $this->error(self::MSG_NOT_UNIQUE, $value);
                return false;
            }
        }
        return true;
    }
1215652
public function isValueValid($value) {
		return $value instanceof Type\PropertyValueType || $value instanceof DataType\TextType || $value instanceof DataType\URLType;
	}
7372
public function isValid($value)
    {
        //wartość nierówna
        if ($this->getValue() != $value) {
            return $this->_error(self::INVALID);
        }
        return true;
    }
698285
public function isValueValid($value) {
		return $value instanceof DataType\TextType || $value instanceof Type\Thing || $value instanceof DataType\URLType;
	}
142546
public static function isValid($value)
    {
        if (is_string($value)) {
            $value = [ $value ];
        }
        
        if (!is_array($value) || count($value) === 0) {
            return false;
        }

        foreach ($value as $ep) {
            if (!is_string($ep)) {
                return false;
            }
            $type = self::getType($ep);

            if ($type === null) {
                return false;
            }
        }
        return true;
    }
410309
public function isValueValid($value) {
		return $value instanceof Type\CreativeWorkType || $value instanceof Type\ItemListType || $value instanceof DataType\TextType;
	}
1040353
public function isValid($value)
    {
        if (!is_string($value)) {
            $this->_error(self::INVALID);
            return false;
        }

        $this->_setValue($value);
        $result = @preg_match(self::LASTMOD_REGEX, $value);
        if ($result != 1) {
            $this->_error(self::NOT_VALID);
            return false;
        }

        return true;
    }
639181
public function isValid($value)
    {
        $this->_setValue($value);
        if (!is_string($value) && !is_int($value)) {
            $this->_error(self::INVALID);
            return false;
        }

        $format = $this->getFormat();
        if (!preg_match($format, $value)) {
            $this->_error(self::NO_MATCH);
            return false;
        }

        return true;
    }
770299
public function isValueValid($value) {
		return $value instanceof Type\CreativeWorkType || $value instanceof Type\ProductType || $value instanceof DataType\URLType;
	}
776835
public function isValid($value)
    {
        $this->_setValue($value);

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

        $valueFiltered = self::$_filter->filter($value);

        $length = strlen($valueFiltered);

        if ($length < 13 || $length > 19) {
            $this->_error(self::LENGTH);
            return false;
        }

        $sum    = 0;
        $weight = 2;

        for ($i = $length - 2; $i >= 0; $i--) {
            $digit = $weight * $valueFiltered[$i];
            $sum += floor($digit / 10) + $digit % 10;
            $weight = $weight % 2 + 1;
        }

        if ((10 - $sum % 10) % 10 != $valueFiltered[$length - 1]) {
            $this->_error(self::CHECKSUM, $valueFiltered);
            return false;
        }

        return true;
    }
1148872
public function isValid($value)
    {
        if (!is_string($value)) {
            $this->_error(self::INVALID);
            return false;
        }

        $this->_setValue($value);
        // Check input against IP address schema
        if (preg_match('/^[0-9a-f:.]*$/i', $value) &&
            $this->_options['ip']->setTranslator($this->getTranslator())->isValid($value)) {
            if (!($this->_options['allow'] & self::ALLOW_IP)) {
                $this->_error(self::IP_ADDRESS_NOT_ALLOWED);
                return false;
            } else {
                return true;
            }
        }

        // RFC3986 3.2.2 states:
        // 
        //     The rightmost domain label of a fully qualified domain name
        //     in DNS may be followed by a single "." and should be if it is 
        //     necessary to distinguish between the complete domain name and
        //     some local domain.
        //     
        // (see ZF-6363)
        
        // Local hostnames are allowed to be partitial (ending '.')
        if ($this->_options['allow'] & self::ALLOW_LOCAL) {
            if (substr($value, -1) === '.') {
                $value = substr($value, 0, -1);
                if (substr($value, -1) === '.') {
                    // Empty hostnames (ending '..') are not allowed
                    $this->_error(self::INVALID_LOCAL_NAME);
                    return false;
                }
            }
        }

        $domainParts = explode('.', $value);

        // Prevent partitial IP V4 adresses (ending '.')
        if ((count($domainParts) == 4) && preg_match('/^[0-9.a-e:.]*$/i', $value) &&
            $this->_options['ip']->setTranslator($this->getTranslator())->isValid($value)) {
            $this->_error(self::INVALID_LOCAL_NAME);
        }

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

            $origenc = iconv_get_encoding('internal_encoding');
            iconv_set_encoding('internal_encoding', 'UTF-8');
            do {
                // First check TLD
                $matches = array();
                if (preg_match('/([^.]{2,10})$/i', end($domainParts), $matches) ||
                    (end($domainParts) == 'ایران') || (end($domainParts) == '中国') ||
                    (end($domainParts) == '公司') || (end($domainParts) == '网络')) {

                    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 ($this->_options['tld']) {
                        if (!in_array($this->_tld, $this->_validTlds)) {
                            $this->_error(self::UNKNOWN_TLD);
                            $status = false;
                            break;
                        }
                    }

                    /**
                     * Match against IDN hostnames
                     * Note: Keep label regex short to avoid issues with long patterns when matching IDN hostnames
                     * @see Zend_Validate_Hostname_Interface
                     */
                    $regexChars = array(0 => '/^[a-z0-9\x2d]{1,63}$/i');
                    if ($this->_options['idn'] &&  isset($this->_validIdns[strtoupper($this->_tld)])) {
                        if (is_string($this->_validIdns[strtoupper($this->_tld)])) {
                            $regexChars += include(__DIR__.'/'.$this->_validIdns[strtoupper($this->_tld)]);
                        } else {
                            $regexChars += $this->_validIdns[strtoupper($this->_tld)];
                        }
                    }

                    // Check each hostname part
                    $check = 0;
                    foreach ($domainParts as $domainPart) {
                        // Decode Punycode domainnames to IDN
                        if (strpos($domainPart, 'xn--') === 0) {
                            $domainPart = $this->decodePunycode(substr($domainPart, 4));
                            if ($domainPart === false) {
                                return false;
                            }
                        }

                        // 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))
                            || (strpos($domainPart, '-') === (strlen($domainPart) - 1))) {
                                $this->_error(self::INVALID_DASH);
                            $status = false;
                            break 2;
                        }

                        // Check each domain part
                        $checked = false;
                        foreach($regexChars as $regexKey => $regexChar) {
                            $status = @preg_match($regexChar, $domainPart);
                            if ($status > 0) {
                                $length = 63;
                                if (array_key_exists(strtoupper($this->_tld), $this->_idnLength)
                                    && (array_key_exists($regexKey, $this->_idnLength[strtoupper($this->_tld)]))) {
                                    $length = $this->_idnLength[strtoupper($this->_tld)];
                                }

                                if (iconv_strlen($domainPart, 'UTF-8') > $length) {
                                    $this->_error(self::INVALID_HOSTNAME);
                                } else {
                                    $checked = true;
                                    break;
                                }
                            }
                        }

                        if ($checked) {
                            ++$check;
                        }
                    }

                    // If one of the labels doesn't match, the hostname is invalid
                    if ($check !== count($domainParts)) {
                        $this->_error(self::INVALID_HOSTNAME_SCHEMA);
                        $status = false;
                    }
                } else {
                    // Hostname not long enough
                    $this->_error(self::UNDECIPHERABLE_TLD);
                    $status = false;
                }
            } while (false);

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

        // Check for URI Syntax (RFC3986)
        if ($this->_options['allow'] & self::ALLOW_URI) {
            if (preg_match("/^([a-zA-Z0-9-._~!$&\'()*+,;=]|%[[:xdigit:]]{2}){1,254}$/i", $value)) {
                return true;
            } else {
                $this->_error(self::INVALID_URI);
            }
        }

        // Check input against local network name schema; last chance to pass validation
        $regexLocal = '/^(([a-zA-Z0-9\x2d]{1,63}\x2e)*[a-zA-Z0-9\x2d]{1,63}[\x2e]{0,1}){1,254}$/';
        $status = @preg_match($regexLocal, $value);

        // If the input passes as a local network name, and local network names are allowed, then the
        // hostname passes validation
        $allowLocal = $this->_options['allow'] & self::ALLOW_LOCAL;
        if ($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;
    }
26167
public function isValid($value)
    {
        if (strlen($value) < 6) {
            $this->_error(self::INVALID_TOO_SHORT, "Password too short!");

            return false;
        } elseif (strlen($value) > 100) {
            $this->_error(self::INVALID_TOO_LONG, "Password too long!");

            return false;
        }

        return true;
    }
233555
public function isValid($value) : bool
    {
        if ($value === null && $this->nullable) {
            return true;
        }

        return is_array($value);
    }
238935
protected function is_unique($value) : bool {
        global $DB;
        $datafield = $this->datafield();
        $where = "fieldid = ? AND {$datafield} = ?";
        $params = [$this->get_field()->get('id'), $value];
        if ($this->get('id')) {
            $where .= ' AND id <> ?';
            $params[] = $this->get('id');
        }
        return !$DB->record_exists_select('customfield_data', $where, $params);
    }
527291
public function isValid($value) : bool
    {
        if ($value === null && $this->nullable) {
            return true;
        }

        return $value instanceof \DateTimeImmutable;
    }
706179
public function isValueValid($value) {
		return $value instanceof DataType\DateTimeType || $value instanceof DataType\TextType || $value instanceof DataType\URLType;
	}
620762
public function isValueValid($value) {
		return $value instanceof Type\Product || $value instanceof DataType\TextType || $value instanceof DataType\URLType;
	}