Checks the keyframes selector value.

@param string $value
@return bool
558123
public function checkValue(&$value)
    {
        if (parent::checkValue($value) === true) {
            if (!preg_match('/^(?:from|to|(?:\d{1,2}|100)%)$/D', $value)) {
                $this->setIsValid(false);
                $this->addValidationError("Invalid value '$value' for the keyframe selector.");

                return false;
            }
            return true;
        }

        return false;
    }
683858
public function isValueValid($value) {
		return $value instanceof DataType\BooleanType || $value instanceof DataType\TextType || $value instanceof DataType\URLType;
	}
10375
protected function checkValidity($value) : bool
    {
        if (preg_match(static::$regex, $value)) {
            return true;
        } elseif ('' === $value) {
            return true;
        } else {
            return false;
        }
    }
593879
public function check($value)
    {
        $this->validateStructure($value);

        if (! $this->refreshFlow) {
            $this->validateTimestamps($value);
        } else {
            $this->validateRefresh($value);
        }
    }
1338425
public static function matches(?string $value): bool
    {
        return $value !== null && 1 === preg_match(self::FORMATTER_PATTERN, $value);
    }
1312272
protected function isValueTooHigh($value)
    {
        // check if the value is not to high.
        if ($this->max !== null) {
            if (((function_exists('bcsub') && floatval(bcsub(
                $this->max,
                $value,
                4
            )) < 0) || $value > $this->max) && ((string)$this->max) != ((string)$value)
            ) {
                return true;
            }
        }
        return false;
    }
66257
public function hasValue($value)
    {
        $index = array_search($value, $this->values);

        if ($index === false) {
            return false;
        }

        return true;
    }
658633
private static function isBooleanValue( $value )
	{
		if ( is_bool( $value ) ) return true;

		$result = filter_var( $value, FILTER_VALIDATE_BOOLEAN, array( 'flags' => FILTER_NULL_ON_FAILURE ) );
		return $result !== null;
	}
253849
private function check($value) {

		if(true === is_string($value)) {
			return false !== filter_var(trim($value), \FILTER_VALIDATE_EMAIL);
		}

		return false;
	}
1256702
public function isValid($value)
    {
        if (!$value) {
            $this->error(self::MISSING_VALUE);
            return false;
        }

        $response = $this->getService()->verify($value);

        if ($response->getStatus() === true) {
            return true;
        }

        $this->error(self::ERR_CAPTCHA);
        return false;
    }
1082464
public static function isValidHtml($value)
    {
        return (true === self::isValidHtmlName($value))
            || (true === self::isValidHtmlValue($value));
    }
510075
public function checkChars($value)
    {
        if ($value[0] == '(') {
            $value = substr($value, 1);

            if ($value[strlen($value) - 1] == ')') {
                $value = substr($value, 0, -1);
            } else {
                return false;
            }
        }

        return parent::checkChars($value);
    }
609213
protected function isValueDisabled($value)
	{
		$disabled = $this->disabled;
		if (is_array($disabled)) {
			return isset($disabled[ $value ]) && $disabled[ $value ];
		}
		elseif (!is_bool($disabled)) {
			return $disabled == $value;
		}

		return FALSE;
	}
851213
public function isValid($value)
    {
        $result = preg_match('/(.+)/i', $value);
        if (!$result) {
            $this->addMessage('notEmpty');
        }
        return (boolean) $result;
    }
849786
public static function isValueType($value)
    {
        if (is_scalar($value) || $value === null) {
            return true;
        } elseif (is_array($value)) {
            $isScalar = true;
            array_walk_recursive($value,
                    function ($value) use (&$isScalar) {
                        if ($isScalar && !(is_scalar($value) || $value === null)) {
                            $isScalar = false;
                        }
                    });

            return $isScalar;
        } else {
            return false;
        }
    }
153355
public function isValid($value)
    {
        $result = (boolean) filter_var($value, FILTER_VALIDATE_URL);
        if (!$result) {
            $this->addMessage('url');
        }
        return $result;
    }
221154
public static function isBooleanValue($value): bool
    {
        return is_bool($value) || self::isBooleanStringValue($value) || self::isBooleanNumericValue($value);
    }