Support extending views, not just models

[kcaswick]

This would allow making extensions completely independent of the base files, which might also be maintained elsewhere. (i.e. a submodule from another team, an open source project that includes diagrams you want to reference, or an automatically generated file)

For example, in next.c4, it could contain:

views {
  extend cloud {
    include next.*
    exclude next -> legacy
  }
}

This would add the planned new system to views, without mentioning next at all in views.c4, which might still be needed for projects that only need to see the legacy system.

It probably makes sense to allow extending in specification at the same time, though at the moment it would only be useful for having a centralized place to add styles to elements.

[davydkov]

Hi @kcaswick

I already have a draft implementation (as a part of the "presentation/slides" mode I was working a while back), like

views {

  view index {
    include ...
  }
  
  view index2 extends index {  
    exclude ...
    include ..
    style ...
  }
  
  view index3 extends index2 {
    ...
  }

}

Implementation could be more subtle, but it does the job. I will release it soon and let you know.

Does this syntax look good for you?

[kcaswick]

Yeah, that looks pretty close.

The only thing missing is being able to add a "viewOf", which I did when I was doing the workaround of copying it and then editing. If that's not easy, I can get by without it though. (I'm combining diagrams for 2 packages, so I want to move an index view from 1 package to be seen when clicking the package element for that package.)

Thanks!

[davydkov]

Released in v0.37.0.

As for “viewOf” - I want to have custom navigation rules, maybe defined per view.

Be honest, I have no idea yet how this might be presented in syntax.