Check is value valid.

@param string $value
@return bool
17175
public function isValueValid($value) {
		return $value instanceof Type\AudienceType || $value instanceof Type\OrganizationType || $value instanceof Type\PersonType;
	}
10375
protected function checkValidity($value) : bool
    {
        if (preg_match(static::$regex, $value)) {
            return true;
        } elseif ('' === $value) {
            return true;
        } else {
            return false;
        }
    }
851213
public function isValid($value)
    {
        $result = preg_match('/(.+)/i', $value);
        if (!$result) {
            $this->addMessage('notEmpty');
        }
        return (boolean) $result;
    }
135337
public function isValid($value)
    {
        $result = filter_var($value, FILTER_VALIDATE_INT);
        if (!$result) {
            $this->addMessage('number');
        }
        return ($result === false) ? false : true;
    }
379250
public function isValueValid($value) {
		return $value instanceof Type\PropertyValue || $value instanceof DataType\TextType || $value instanceof DataType\URLType;
	}
1319912
public function isValid($value)
    {
        $valueString = (string) $value;

        $this->_setValue($valueString);

        if (ip2long($valueString) === false) {
            $this->_error();
            return false;
        }

        return true;
    }
253515
public function isValueValid($value) {
		return $value instanceof Type\AlignmentObject || $value instanceof Type\Course || $value instanceof DataType\TextType;
	}
787118
protected function isValid($value)
    {
        $value = (string) $value;
        foreach (static::$enumConstants[get_class($this)] as $constantValue) {
            if ($value === (string) $constantValue) {
                return true;
            }
        }
        return false;
    }
217771
public function isValid($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;
    }
833363
public function isValueValid($value) {
		return $value instanceof Type\CreativeWork || $value instanceof Type\ItemList || $value instanceof DataType\TextType;
	}
770299
public function isValueValid($value) {
		return $value instanceof Type\CreativeWorkType || $value instanceof Type\ProductType || $value instanceof DataType\URLType;
	}
1179696
public function isValueValid($value) {
		return $value instanceof Type\GeoShapeType || $value instanceof Type\PlaceType || $value instanceof DataType\TextType;
	}
111836
public function isValueValid($value) {
		return $value instanceof Type\Place || $value instanceof Type\PostalAddress || $value instanceof DataType\TextType;
	}
186143
public function isValueValid($value) {
		return $value instanceof Type\AlignmentObjectType || $value instanceof Type\CourseType || $value instanceof DataType\TextType;
	}
1296136
public function isValid($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;
    }
620762
public function isValueValid($value) {
		return $value instanceof Type\Product || $value instanceof DataType\TextType || $value instanceof DataType\URLType;
	}
950210
public function isValueValid($value) {
		return $value instanceof DataType\BooleanType || $value instanceof DataType\NumberType || $value instanceof Type\StructuredValueType || $value instanceof DataType\TextType;
	}