Optional GET parameter on webservice call

[rdubois-mel]

Hi,

I use Hop webservices to launch pipelines as explained in the documentation (https://hop.apache.org/manual/latest/hop-server/web-service.html). It works very well.
But I would like to pass optional GET parameters to my pipeline.

Currently I use the "Get variables" transform, but if I do not pass my parameter or if I pass an empty string as an integer, I get a Serialization error.
I have tested all possible types and still encounter an error.

Is there a way around this? or another way to retrieve GET parameters?

Thanks !
Remi