Uses columns_for from VegaLite (#48)

Co-authored-by: José Valim <jose.valim@gmail.com>

lib/kino_vega_lite/chart_cell.ex

@@ -555,23 +555,15 @@ defmodule KinoVegaLite.ChartCell do
 
   defp missing_dep() do
     unless Code.ensure_loaded?(VegaLite) do
-      ~s/{:vega_lite, "~> 0.1.4"}/
+      ~s/{:vega_lite, "~> 0.1.8"}/
     end
   end
 
   defp columns_for(data) do
-    with true <- implements?(Table.Reader, data),
-         data = {_, %{columns: [_ | _] = columns}, _} <- Table.Reader.init(data),
-         true <- Enum.all?(columns, &implements?(String.Chars, &1)) do
-      types = infer_types(data)
-      Enum.zip_with(columns, types, fn column, type -> %{name: to_string(column), type: type} end)
-    else
-      _ -> nil
-    end
+    if cols = VegaLite.Data.columns_for(data),
+      do: Enum.map(cols, fn {k, v} -> %{name: k, type: to_string(v)} end)
   end
 
-  defp implements?(protocol, value), do: protocol.impl_for(value) != nil
-
   defp encode(@count_field), do: :encode
   defp encode(_), do: :encode_field
 
@@ -590,33 +582,6 @@ defmodule KinoVegaLite.ChartCell do
     end
   end
 
-  defp infer_types({:columns, %{columns: _columns}, data}) do
-    Enum.map(data, fn data -> data |> Enum.at(0) |> type_of() end)
-  end
-
-  defp infer_types({:rows, %{columns: columns}, data}) do
-    case Enum.fetch(data, 0) do
-      {:ok, row} -> Enum.map(row, &type_of/1)
-      :error -> Enum.map(columns, fn _ -> nil end)
-    end
-  end
-
-  defp type_of(%mod{}) when mod in [Decimal], do: "quantitative"
-  defp type_of(%mod{}) when mod in [Date, NaiveDateTime, DateTime], do: "temporal"
-
-  defp type_of(data) when is_number(data), do: "quantitative"
-
-  defp type_of(data) when is_binary(data) do
-    if date?(data) or date_time?(data), do: "temporal", else: "nominal"
-  end
-
-  defp type_of(data) when is_atom(data), do: "nominal"
-
-  defp type_of(_), do: nil
-
-  defp date?(value), do: match?({:ok, _}, Date.from_iso8601(value))
-  defp date_time?(value), do: match?({:ok, _, _}, DateTime.from_iso8601(value))
-
   defp default_layer() do
     %{
       "chart_type" => "point",

mix.exs

@@ -28,7 +28,7 @@ defmodule KinoVegaLite.MixProject do
     [
       {:kino, "~> 0.7"},
       {:table, "~> 0.1.0"},
-      {:vega_lite, "~> 0.1.4"},
+      {:vega_lite, "~> 0.1.8"},
       {:ex_doc, "~> 0.28", only: :dev, runtime: false}
     ]
   end

mix.lock

@@ -7,5 +7,5 @@
   "makeup_erlang": {:hex, :makeup_erlang, "0.1.1", "3fcb7f09eb9d98dc4d208f49cc955a34218fc41ff6b84df7c75b3e6e533cc65f", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "174d0809e98a4ef0b3309256cbf97101c6ec01c4ab0b23e926a9e17df2077cbb"},
   "nimble_parsec": {:hex, :nimble_parsec, "1.2.3", "244836e6e3f1200c7f30cb56733fd808744eca61fd182f731eac4af635cc6d0b", [:mix], [], "hexpm", "c8d789e39b9131acf7b99291e93dae60ab48ef14a7ee9d58c6964f59efb570b0"},
   "table": {:hex, :table, "0.1.2", "87ad1125f5b70c5dea0307aa633194083eb5182ec537efc94e96af08937e14a8", [:mix], [], "hexpm", "7e99bc7efef806315c7e65640724bf165c3061cdc5d854060f74468367065029"},
-  "vega_lite": {:hex, :vega_lite, "0.1.4", "97f3f59f1a8b65169aa7dd861b0e13d10fb73e18b1f8546b953c34a74cab33ef", [:mix], [{:table, "~> 0.1.0", [hex: :table, repo: "hexpm", optional: false]}], "hexpm", "b9d0ec3e978b9d1b1a37024e218391f9c1d5a90b783ed2ed988bf5a9b2fddefb"},
+  "vega_lite": {:hex, :vega_lite, "0.1.8", "7f6119126ecaf4bc2c1854084370d7091424f5cce4795fbac044eee9963f0752", [:mix], [{:table, "~> 0.1.0", [hex: :table, repo: "hexpm", optional: false]}], "hexpm", "6c8a9271f850612dd8a90de8d1ebd433590ed07ffef76fc2397c240dc04d3fdc"},
 }

test/kino_vega_lite/chart_cell_test.exs

@@ -76,16 +76,16 @@ defmodule KinoVegaLite.ChartCellTest do
 
     data_options = [
       %{
-        variable: "row_data",
-        columns: [%{name: "x", type: "quantitative"}, %{name: "y", type: "quantitative"}]
+        columns: [%{name: "x", type: "quantitative"}, %{name: "y", type: "quantitative"}],
+        variable: "row_data"
       },
       %{
-        variable: "column_data",
-        columns: [%{name: "x", type: "quantitative"}, %{name: "y", type: "quantitative"}]
+        columns: [%{name: "x", type: "quantitative"}, %{name: "y", type: "quantitative"}],
+        variable: "column_data"
       },
       %{
-        variable: "temporal_data",
-        columns: [%{name: "x", type: "nominal"}, %{name: "y", type: "temporal"}]
+        columns: [%{name: "x", type: "nominal"}, %{name: "y", type: "temporal"}],
+        variable: "temporal_data"
       }
     ]