{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "background": "white",
  "padding": 5,
  "data": [
    {
      "name": "data_source",
      "values": [
        {"location": "US", "category": "low", "value": 1},
        {"location": "US", "category": "high", "value": 2},
        {"location": "US", "category": "high", "value": 3},
        {"location": "UK", "category": "low", "value": 2},
        {"location": "UK", "category": "high", "value": 3},
        {"location": "UK", "category": "high", "value": 4}
      ]
    },
    {
      "name": "column_domain",
      "source": "data_source",
      "transform": [{"type": "aggregate", "groupby": ["location"]}]
    },
    {
      "name": "data_2",
      "source": "data_source",
      "transform": [
        {
          "type": "aggregate",
          "groupby": ["category", "location"],
          "ops": ["sum"],
          "fields": ["value"],
          "as": ["sum_value"]
        },
        {
          "type": "stack",
          "groupby": ["category", "location"],
          "field": "sum_value",
          "sort": {"field": ["location"], "order": ["ascending"]},
          "as": ["sum_value_start", "sum_value_end"],
          "offset": "zero"
        },
        {
          "type": "filter",
          "expr": "isValid(datum[\"sum_value\"]) && isFinite(+datum[\"sum_value\"])"
        }
      ]
    }
  ],
  "signals": [
    {"name": "child_width", "value": 300},
    {"name": "y_step", "value": 20},
    {
      "name": "child_height",
      "update": "bandspace(domain('y').length, 0.1, 0.05) * y_step"
    }
  ],
  "layout": {
    "padding": 20,
    "offset": {"columnTitle": 10},
    "columns": {"signal": "length(data('column_domain'))"},
    "bounds": "full",
    "align": "all"
  },
  "marks": [
    {
      "name": "column-title",
      "type": "group",
      "role": "column-title",
      "title": {"text": "location", "style": "guide-title", "offset": 10}
    },
    {
      "name": "row_header",
      "type": "group",
      "role": "row-header",
      "encode": {"update": {"height": {"signal": "child_height"}}},
      "axes": [
        {
          "scale": "y",
          "orient": "left",
          "grid": false,
          "title": "category",
          "zindex": 0
        }
      ]
    },
    {
      "name": "column_header",
      "type": "group",
      "role": "column-header",
      "from": {"data": "column_domain"},
      "sort": {"field": "datum[\"location\"]", "order": "ascending"},
      "title": {
        "text": {
          "signal": "isValid(parent[\"location\"]) ? parent[\"location\"] : \"\"+parent[\"location\"]"
        },
        "style": "guide-label",
        "frame": "group",
        "offset": 10
      },
      "encode": {"update": {"width": {"signal": "child_width"}}}
    },
    {
      "name": "column_footer",
      "type": "group",
      "role": "column-footer",
      "from": {"data": "column_domain"},
      "sort": {"field": "datum[\"location\"]", "order": "ascending"},
      "encode": {"update": {"width": {"signal": "child_width"}}},
      "axes": [
        {
          "scale": "x",
          "orient": "bottom",
          "grid": false,
          "title": "Sum of value",
          "labelFlush": true,
          "labelOverlap": true,
          "tickCount": {"signal": "ceil(child_width/40)"},
          "zindex": 0
        }
      ]
    },
    {
      "name": "cell",
      "type": "group",
      "style": "cell",
      "from": {
        "facet": {
          "name": "facet",
          "data": "data_source",
          "groupby": ["location"]
        }
      },
      "sort": {"field": ["datum[\"location\"]"], "order": ["ascending"]},
      "data": [
        {
          "source": "facet",
          "name": "data_0",
          "transform": [
            {
              "type": "aggregate",
              "groupby": ["category", "location"],
              "ops": ["sum"],
              "fields": ["value"],
              "as": ["sum_value"]
            },
            {
              "type": "stack",
              "groupby": ["category"],
              "field": "sum_value",
              "sort": {"field": ["location"], "order": ["ascending"]},
              "as": ["sum_value_start", "sum_value_end"],
              "offset": "zero"
            },
            {
              "type": "filter",
              "expr": "isValid(datum[\"sum_value\"]) && isFinite(+datum[\"sum_value\"])"
            }
          ]
        }
      ],
      "encode": {
        "update": {
          "width": {"signal": "child_width"},
          "height": {"signal": "child_height"}
        }
      },
      "marks": [
        {
          "name": "child_marks",
          "type": "rect",
          "style": ["bar"],
          "from": {"data": "data_0"},
          "encode": {
            "update": {
              "fill": {"scale": "color", "field": "location"},
              "ariaRoleDescription": {"value": "bar"},
              "description": {
                "signal": "\"Sum of value: \" + (format(datum[\"sum_value\"], \"\")) + \"; category: \" + (isValid(datum[\"category\"]) ? datum[\"category\"] : \"\"+datum[\"category\"]) + \"; location: \" + (isValid(datum[\"location\"]) ? datum[\"location\"] : \"\"+datum[\"location\"])"
              },
              "x": {"scale": "x", "field": "sum_value_end"},
              "x2": {"scale": "x", "field": "sum_value_start"},
              "y": {"scale": "y", "field": "category"},
              "height": {"signal": "max(0.25, bandwidth('y'))"}
            }
          }
        }
      ],
      "axes": [
        {
          "scale": "x",
          "orient": "bottom",
          "gridScale": "y",
          "grid": true,
          "tickCount": {"signal": "ceil(child_width/40)"},
          "domain": false,
          "labels": false,
          "aria": false,
          "maxExtent": 0,
          "minExtent": 0,
          "ticks": false,
          "zindex": 0
        }
      ]
    }
  ],
  "scales": [
    {
      "name": "x",
      "type": "linear",
      "domain": {
        "data": "data_2",
        "fields": ["sum_value_start", "sum_value_end"]
      },
      "range": [0, {"signal": "child_width"}],
      "nice": true,
      "zero": true
    },
    {
      "name": "y",
      "type": "band",
      "domain": {
        "data": "data_source",
        "field": "category",
        "sort": {"op": "sum", "field": "value", "order": "descending"}
      },
      "range": {"step": {"signal": "y_step"}},
      "paddingInner": 0.1,
      "paddingOuter": 0.05
    },
    {
      "name": "color",
      "type": "ordinal",
      "domain": {"data": "data_2", "field": "location", "sort": true},
      "range": "category"
    }
  ],
  "legends": [{"fill": "color", "symbolType": "square", "title": "location"}]
}