Check if $value is a valid QTI Identifier.

@throws \InvalidArgumentException If $value is not a valid QTI Identifier.
775168
protected function checkType($value)
    {
        if (gettype($value) !== 'string') {
            $msg = "IdentifierCollection class only accept string values, '" . gettype($value) . "' given.";
            throw new InvalidArgumentException($msg);
        } elseif (!Format::isIdentifier($value)) {
            $msg = "IdentifierCollection class only accept valid QTI Identifiers, '${value}' given.";
            throw new InvalidArgumentException($msg);
        }
    }
103205
protected function verifyElement($value)
    {
        if (!$this->elementType->isOfType($value)) {
            throw Exception\InvalidArgumentException::format(
                'Invalid element supplied to collection: expecting type of %s, %s given',
                $this->elementType->asTypeString(), Debug::getType($value)
            );
        }
    }
1162151
protected function isValid($value) {

		if(!($value instanceof PersistentResource)) {
			$this->addError('Given value is no Flow Resource', 1433344498);
		}

		$fileMimeType = $value->getMediaType();

		if(!\in_array($fileMimeType, $this->options['allowedMimeTypes'], true)) {
			$this->addError(
				'The given asset was not of type %1$s but is of type %2$s',
				1433343575,
				array(
					implode(', ', $this->options['allowedMimeTypes']),
					$fileMimeType
				)
		);
		}

	}
662361
protected function isValid($value)
    {
        if (!is_numeric($value)) {
            $this->addError('A valid number is expected.', 1221563685);
            return;
        }

        $minimum = $this->options['minimum'];
        $maximum = $this->options['maximum'];
        if ($minimum > $maximum) {
            $x = $minimum;
            $minimum = $maximum;
            $maximum = $x;
        }
        if ($value < $minimum || $value > $maximum) {
            $this->addError('Please enter a valid number between %1$d and %2$d.', 1221561046, [$minimum, $maximum]);
        }
    }
113635
public function isValueValid($value) {
		return $value instanceof Type\MonetaryAmountType || $value instanceof DataType\NumberType || $value instanceof Type\PriceSpecificationType;
	}
217771
public function isValid($value)
    {
        $valueString = (string) $value;

        $this->_setValue($valueString);

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

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

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

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

        return true;
    }
1000801
public function isValueValid($value) {
		return $value instanceof Type\Distance || $value instanceof DataType\NumberType || $value instanceof DataType\TextType;
	}
450703
protected function isValid($value)
    {
        if (is_null($value)) {
            return;
        } elseif ($value) {
            $context = [$value];
        } else {
            $context = [];
        }

        $q = new FlowQuery($context);

        if ($q->is('[instanceof ' . $this->options['type'] . ']')) {
            return;
        }

        $this->addError('The value is expected to satisfy the %s flowQuery condition.', 1515144113, [
            $this->options['type']
        ]);
    }
299934
public function isValueValid($value) {
		return $value instanceof Type\MenuType || $value instanceof DataType\TextType || $value instanceof DataType\URLType;
	}
450467
public function isValueValid($value) {
		return $value instanceof Type\QualitativeValueType || $value instanceof DataType\TextType || $value instanceof DataType\URLType;
	}
937672
public function isValid($value)
    {
        $acceptedValues = GeneralUtility::trimExplode('|', $this->options['values']);

        if (false === in_array($value, $acceptedValues)) {
            $errorMessage = $this->translateErrorMessage('validator.has_values.not_valid', 'configuration_object', [implode(', ', $acceptedValues)]);
            $this->addError($errorMessage, 1456140151);
        }
    }
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;
    }
298000
public function isValid($value)
    {
        $value = (string) $value;
        if (strlen($value) !== 10) {
            $this->_error(self::INVALID_NIP, $value);
            return false;
        }

        $intSum = 0;

        for ($i = 0; $i < 9; $i++) {
            $intSum += $this->_weights[$i] * $value[$i];
        }

        $int = $intSum % 11;
        $intControlNr = ($int === 10) ? 0 : $int;

        if ($intControlNr !== (int) $value[9]) {
            $this->_error(self::INVALID_NIP, $value);
            return false;
        }

        return true;
    }
379250
public function isValueValid($value) {
		return $value instanceof Type\PropertyValue || $value instanceof DataType\TextType || $value instanceof DataType\URLType;
	}
393972
public function isValid($value) {
		if (is_int($value) || is_float($value)) {
			return true;
		}
		
		$this->addMessage('Value must be a digital');
		
		return false;
	}
292318
public function isValid($value)
    {
        if (false === Core::get()->classExists($value)) {
            $errorMessage = $this->translateErrorMessage('validator.class_exists.not_valid', 'configuration_object', [$value]);
            $this->addError($errorMessage, 1457610460);
        }
    }
1215652
public function isValueValid($value) {
		return $value instanceof Type\PropertyValueType || $value instanceof DataType\TextType || $value instanceof DataType\URLType;
	}