Why do we need geojson type?

[domoritz]

We only use the type geojson for shapes. However, we don't need it if we join a dataset into an existing geojson.

We can reverse the geo repeat example

{
  "$schema": "https://vega.github.io/schema/vega-lite/v2.1.json",
  "description": "the population per state, engineers per state, and hurricanes per state",
  "repeat": {"row": ["population", "engineers", "hurricanes"]},
  "resolve": {
    "scale": {
      "color": "independent"
    }
  },
  "spec": {
    "width": 500,
    "height": 300,
    "data": {
      "url": "data/us-10m.json",
      "format": {
        "type": "topojson",
        "feature": "states"
      }
    },
    "transform": [
      {
        "lookup": "id",
        "from": {
          "data": {
            "url": "data/population_engineers_hurricanes.csv"
          },
          "key": "id",
          "fields": ["population", "engineers", "hurricanes"]
        }
      }
    ],
    "projection": {"type": "albersUsa"},
    "mark": "geoshape",
    "encoding": {
      "color": {
        "field": {"repeat": "row"},
        "type": "quantitative"
      }
    }
  }
}

I understand that it sometimes may make sense to do this the other way around. For instance, if data is missing or you want to run an aggregation. However, how important are these cases? Do we have one or two compelling use cases?

[kanitw]

We also discussed that geoshape may be a better name that we might consider changing later.

[iliatimofeev]

This might be related to current topic vega/vega#1319 .

"format": {
      "type": "geojson",
      "feature": "features", // like topojson or jpath 
      "properties": "foreign" // default value "nested"
}

Suggestion is to support GeoJSON format directly, see @mattijn motivation in vega issue.

[kanitw]

I think that we won't change this.

Note that the format type discussion is different from the field type here.