Ranges with selectors

[stephenwf]

Currently when parsing ranges, the id is pulled out and used as a canvas reference.

https://github.com/IIIF-Commons/parser/blob/main/src/presentation-3/traverse.ts#L348-L350

{
  "type": "Range",
  "items": [
     "https://example.org/canvas-1#xywh=0,1,2,3"
  ]
}

But if the ID contains a #xywh=0,1,2,3 it will produce an invalid reference:

{
  "type": "Range",
  "items": [
    { "id": "https://example.org/canvas-1#xywh=0,1,2,3", "type": "Canvas" }
  ]
}

This is still an improvement on the original, normalising to the id / type but breaks the usual vault.get(ref) model, which you might expect to return.

This also relates to Annotation['target'] types, which are not currently normalized, for the same reason.

[stephenwf]

Also SpecificResource

[stephenwf]

One possibility is to normalise:

{
  "type": "Range",
  "items": [
     "https://example.org/canvas-1#xywh=0,1,2,3",
    { "id": "https://example.org/canvas-2#xywh=0,1,2,3", "type": "Canvas" }
    { 
      "type": "SpecificResource", 
      "source": "https://example.org/canvas-3", 
      "selector": {
        "type": "FragmentSelector",
        "value": "xywh=0,1,2,3"
      } 
    }
  ]
}

into:

{
  "type": "Range",
  "items": [
    { 
      "type": "SpecificResource", 
      "source": {"id": "https://example.org/canvas-1", "type": "Canvas"},
      "selector": {
        "type": "FragmentSelector",
        "value": "xywh=0,1,2,3"
      } 
    }
    { 
      "type": "SpecificResource", 
      "source": {"id": "https://example.org/canvas-2", "type": "Canvas"},
      "selector": {
        "type": "FragmentSelector",
        "value": "xywh=0,1,2,3"
      } 
    }
    { 
      "type": "SpecificResource", 
      "source": {"id": "https://example.org/canvas-3", "type": "Canvas"},
      "selector": {
        "type": "FragmentSelector",
        "value": "xywh=0,1,2,3"
      } 
    }
  ]
}

and then feed that into the pipeline, along side ranges? An ID would be generated, need to make sure that on the way out there is an option for compressing the specific resource.

This could work along side an additional capability for vault.get() to allow:

vault.get('https://example.org/canvas-1');
vault.get({ id: 'https://example.org/canvas-1', type: 'Canvas' });
vault.get({ 
  type: 'SpecificResource', 
  source: { id: 'https://example.org/canvas-1', type: 'Canvas' },
});
vault.get({ 
  type: 'SpecificResource', 
  source: 'https://example.org/canvas-1',
});
vault.get({ 
  type: 'SpecificResource', 
  source: 'https://example.org/canvas-1',
  selector: {
    type: 'FragmentSelector',
    value" 'xywh=0,1,2,3'
  } 
});

Where these would all return the same thing. You would still need something like the Vault helper to parse the selector itself.

[stephenwf]

A new vault helper / part of vault might be an equality helper:

resourceEquals(a, b);

Where a and b could be any of the above (string, reference, specific resource)