[sc34wg3] Explanation in TMCL?

[Lars Marius Garshol]

* Robert Cerny
> 
> As already stated i am using TMCL for form generation. In this use case it is necessary to explain to the user why his input is invalid and what he should do to make it valid. I was wondering if it tmcl:description is appropriate for this message [...]

Probably not. It's meant for a description of the construct it's attached to, and I guess it's not a given that that would make sense as an explanation of what's wrong.

> or whether something like this is necessary:
> 
> tmcl:explanation isa tmcl:occurrence-type;
>  has-datatype(xsd:string).
> 
> tmcl:constraint
>  has-occurrence(tmcl:explanation, 0, *).

Yes, this (except perhaps "0, 1", since presumably one explanation is enough) looks better. However, I think this is outside the scope of TMCL, so that it's better if you define your own occurrence type.

Note that something similar has already been proposed by me and rejected by the committee: http://projects.topicmapslab.de/issues/1447

--Lars M.
http://www.garshol.priv.no/tmphoto/
http://www.garshol.priv.no/blog/