Viewhelper-arguments are marked as wrong, if the arguments-names are defined with php constants.
The extension remarks an error, if I define the custom argument of my viewhelper in the following way:
const SVG_VIEWHELPER_ARGUMENTS_REMOVE_WHITESPACE = 'removeWhitespace';
....
$this->registerArgument(self::SVG_VIEWHELPER_ARGUMENTS_REMOVE_WHITESPACE,
'string',
'This definition will mark the attribute "removeWhitespace" in the template as wrong/undefined.'
);
The following definition allow the attribute 'removeWhitespace' in my custom viewhelper.
$this->registerArgument('removeWhitespace',
'string',
'This definition allow the attribute "removeWhitespace" in my viewhelper.'
);