Feature collection link to GeoJSON items does not include f=json in href

[mdastous-bentley]

Hi,

I'm relatively new to OGC Features, and I'm currently trying to implement a OGC Feature client.
I'm using Tipg as my test server and just noticed that collection links seem invalid. For example here is the result for the sample countries dataset:
http://localhost:8081/collections/public.countries?f=json

{
  "id": "public.countries",
  "title": "public.countries",
  "links": [
    {
      "href": "http://localhost:8081/collections/public.countries",
      "rel": "self",
      "type": "application/json"
    },
    {
      "href": "http://localhost:8081/collections/public.countries/items",
      "rel": "items",
      "type": "application/geo+json",
      "title": "Items"
    },
    {
      "href": "http://localhost:8081/collections/public.countries/items?f=csv",
      "rel": "alternate",
      "type": "text/csv",
      "title": "Items (CSV)"
    },
    {
      "href": "http://localhost:8081/collections/public.countries/items?f=geojsonseq",
      "rel": "alternate",
      "type": "application/geo+json-seq",
      "title": "Items (GeoJSONSeq)"
    },
    {
      "href": "http://localhost:8081/collections/public.countries/queryables",
      "rel": "queryables",
      "type": "application/schema+json",
      "title": "Queryables"
    }
  ],
  "extent": {
    "spatial": {
      "bbox": [
        [
          -180.0,
          -89.99893188476562,
          180.0,
          83.599609375
        ]
      ],
      "crs": "http://www.opengis.net/def/crs/OGC/1.3/CRS84"
    }
  },
  "itemType": "feature",
  "crs": [
    "http://www.opengis.net/def/crs/OGC/1.3/CRS84"
  ]
}

It looks like the items link for application/geo+json type should be:
http://localhost:8081/collections/public.countries/items?f=geojson
instead of:
http://localhost:8081/collections/public.countries/items
which in fact returns an HTML format.

Or maybe I'm missing something?

Thanks

[vincentsarago]

@mdastous-bentley thank's for the report, I agree that we should have f=geojson there

[vincentsarago]

also I think by default without any accept headers the response should be of type application/geo+json not html

http://localhost:8081/collections/public.countries/items will only return an HTML if used in a browser

[mdastous-bentley]

Do you mean the self link here? If so, it currently return html in the browser but advertised as application/json

[vincentsarago]

both self

    {
      "href": "http://localhost:8081/collections/public.countries",
      "rel": "self",
      "type": "application/json"
    }

and items

   {
      "href": "http://localhost:8081/collections/public.countries/items",
      "rel": "items",
      "type": "application/geo+json",
      "title": "Items"
    }

have default to json and geo+json (you can verify this when using curl)

# COLLECTION
curl http://127.0.0.1:8000/collections/public.countries --verbose                      
*   Trying 127.0.0.1:8000...
* Connected to 127.0.0.1 (127.0.0.1) port 8000 (#0)
> GET /collections/public.countries HTTP/1.1
> Host: 127.0.0.1:8000
> User-Agent: curl/8.1.2
> Accept: */*
> 
< HTTP/1.1 200 OK
< date: Tue, 05 Mar 2024 13:48:15 GMT
< server: uvicorn
< content-length: 961
< content-type: application/json
< cache-control: public, max-age=3600
< 
* Connection #0 to host 127.0.0.1 left intact

# ITEMS
curl http://127.0.0.1:8000/collections/public.countries/items --verbose
*   Trying 127.0.0.1:8000...
* Connected to 127.0.0.1 (127.0.0.1) port 8000 (#0)
> GET /collections/public.countries/items HTTP/1.1
> Host: 127.0.0.1:8000
> User-Agent: curl/8.1.2
> Accept: */*
> 
< HTTP/1.1 200 OK
< date: Tue, 05 Mar 2024 13:48:44 GMT
< server: uvicorn
< content-length: 105743
< content-type: application/geo+json
< cache-control: public, max-age=3600
< 

Both links are advertised with their defaults, but in browser, a header Accept: text/html will be automatically added, and thus tipg endpoint will return html content (instead of the default json type).

tipg output format depends on two things:

• query-parameter: f=html
• headers: Accept: text/html

I think this is not well described in the openapi documentation

ref: https://docs.ogc.org/is/17-069r4/17-069r4.html#encodings

[mdastous-bentley]

oh I see, this is probably going to be an infinite source of confusion.