Prevent launch when there are build errors

[scala-ide]

Prevent launch when there are build errors

[milessabin]

Hmm ... I'm not super keen on hard-coding a dependency on Scala IDE bundles. Isn't there a more generic way of recognizing build errors?

[dragos]

I agree. AFAIK, there's no way around that: the launcher has to decide what marker ID it recognises, and by default it's the JDT ones. One way is to have an optional dependency, and at runtime check to see if the bundle is loaded.. if it is, perform the additional checks, otherwise do nothing.

An alternative is to hardcode the ID (it's a string, unlikely to change). I can implement either one, just let me know what you prefer :)

[milessabin]

How about an extension point? You could register marker ids of interest with the launcher (which would default to the JDT ones as it does now).

[dragos]

We run into the same issue: I don't want to have a hard dependency on the weaving launcher either :) Most Scala projects don't need it, it's only for Scala IDE devs.

[milessabin]

Hmm ... How about adding an attribute to the error markers?

[dragos]

Yes, this would work. But then we have the problem of where to define the attribute name. If it's on the weaving-launcher side, we'd need a dependency in Scala IDE. And the other way around.

Here's an alternative: markers have super-types, and Scala problem markers extend jdt.core problem markers. The default implementation checks for exact match, but the weaving launcher could check that the marker is a subtype of the jdt problem marker. WDYT?

[milessabin]

So long as the string is well-known and guaranteed to be fixed I don't think that's too much of a problem. OTOH checking for a JDT problem marker subtype works too and arguably ought to be done anyway. So, yup, something along those lines would be good :-)

[dragos]

I'd go for subtyping any day! :)