importing specs into a layer

[grsr]

Hi - In a complex plot we're building up we'd like to reuse the same spec as a layer in multiple views concatenated together in an outer plot. The docs suggests this might be possible, and works fine for concatenation but I get an error "Error: LayerView accepts only unit or layer specs as children!" I'm trying something like:

"layer": [ {"import": {"url": "my_common_spec.json"} }, { ... }]

Does importing a spec into a layer, rather than in a concat, break some assumptions in GenomeSpy? The alternative approach is just to copy the same layer config into each spec, resulting in a bit of redundancy, but not the end of the world.

Thanks for any pointers or suggestions on how to work around this.

[tuner]

Ah, layer views can have only units (i.e., marks) or other layers as its children. It makes no sense to have, for example, concatenation as one of the layers.

I think the main problem in having imported layers is difficulty in validating the view hierarchy. Currently a view specification is converted into a view hierarchy in the constructors of the View classes (e.g.., View, LayerView, UnitView, ...). When there's "import" in the spec, a temporary ImportView is created and it's later changed into the actual view. Thus, it cannot be know beforehand whether the imported views make sense as children of, for example, a LayerView.

Maybe the current behavior could be relaxed a bit. I'm anyway not satisfied with the current implementation because there are some typing issues (I'm using typescript through JSDoc tags), and parametrised imports should be implemented at some point: #56

[tuner]

Btw, this should work now.

I'm using the following:

      "spec": {
        "title": "Genomic data",

        "resolve": {
          "scale": { "color": "independent", "fill": "independent" }
        },

        "layer": [
          { "import": { "url": "cnv-segments.json" } },
          { "import": { "url": "short-variants.json" } }
        ]
      }

And it's now possible to do (some) parameterization: https://genomespy.app/docs/grammar/import/#repeating-with-named-templates