firefox - Is there a reliable way to determine if a browser supports a particular SVG filter from within SVG code? -

firefox - Is there a reliable way to determine if a browser supports a particular SVG filter from within SVG code? -

in theory requiredfeatures attribute in svg should solve that, seems browsers not study abilities correctly. illustration firefox reports false requiredfeatures ="http://www.w3.org/tr/svg11/feature#basicfilter" , requiredfeatures="http://www.w3.org/tr/svg11/feature#filter" though back upwards filters. here's feature test svg: https://mdn.mozillademos.org/files/3286/requiredfeatures.svg

firefox svg