Make geo optional (#90)

Author: wojtekmach

README.md

@@ -113,15 +113,13 @@ point, polygon, ...  %Geo.Point{coordinates: {0.0, 1.0}}, ... *****
 \*\*\*\* MySQL added a native JSON type in version 5.7.8, if you're using earlier versions,
 remember to use TEXT column for your JSON field.
 
-\*\*\*\*\* Encoding/decoding between `Geo.*` structs and the OpenGIS WKB binary format is
-done using the [Geo](https://github.com/bryanjos/geo) package. If you're using MyXQL geometry
-types with Ecto and need to for example accept a WKT format as user input, consider implementing an
-[custom Ecto type](https://hexdocs.pm/ecto/Ecto.Type.html). Note, some structs like `%Geo.PointZ{}`
-does not have equivalent on the MySQL server side and thus shouldn't be used.
+\*\*\*\*\* See "Geometry support" section below
 
 ## JSON support
 
-MyXQL comes with JSON support out of the box via the [Jason](https://github.com/michalmuskala/jason) library. To use it, add `:jason` to your dependencies:
+MyXQL comes with JSON support via the [Jason](https://github.com/michalmuskala/jason) library.
+
+To use it, add `:jason` to your dependencies:
 
 ```elixir
 {:jason, "~> 1.0"}
@@ -133,6 +131,22 @@ You can customize it to use another library via the `:json_library` configuratio
 config :myxql, :json_library, SomeJSONModule
 ```
 
+## Geometry support
+
+MyXQL comes with Geometry types support via the [Geo](https://github.com/bryanjos/geo) package.
+
+To use it, add `:geo` to your dependencies:
+
+```elixir
+{:geo, "~> 3.3"}
+```
+
+Note, some structs like `%Geo.PointZ{}` does not have equivalent on the MySQL server side and thus
+shouldn't be used.
+
+If you're using MyXQL geometry types with Ecto and need to for example accept a WKT format as user
+input, consider implementing an [custom Ecto type](https://hexdocs.pm/ecto/Ecto.Type.html).
+
 ## Contributing
 
 Run tests:

lib/myxql/protocol/values.ex

@@ -223,13 +223,15 @@ defmodule MyXQL.Protocol.Values do
     {:mysql_type_tiny, <<0>>}
   end
 
-  def encode_binary_value(%Geo.Point{} = geo), do: encode_geometry(geo)
-  def encode_binary_value(%Geo.MultiPoint{} = geo), do: encode_geometry(geo)
-  def encode_binary_value(%Geo.LineString{} = geo), do: encode_geometry(geo)
-  def encode_binary_value(%Geo.MultiLineString{} = geo), do: encode_geometry(geo)
-  def encode_binary_value(%Geo.Polygon{} = geo), do: encode_geometry(geo)
-  def encode_binary_value(%Geo.MultiPolygon{} = geo), do: encode_geometry(geo)
-  def encode_binary_value(%Geo.GeometryCollection{} = geo), do: encode_geometry(geo)
+  if Code.ensure_loaded?(Geo) do
+    def encode_binary_value(%Geo.Point{} = geo), do: encode_geometry(geo)
+    def encode_binary_value(%Geo.MultiPoint{} = geo), do: encode_geometry(geo)
+    def encode_binary_value(%Geo.LineString{} = geo), do: encode_geometry(geo)
+    def encode_binary_value(%Geo.MultiLineString{} = geo), do: encode_geometry(geo)
+    def encode_binary_value(%Geo.Polygon{} = geo), do: encode_geometry(geo)
+    def encode_binary_value(%Geo.MultiPolygon{} = geo), do: encode_geometry(geo)
+    def encode_binary_value(%Geo.GeometryCollection{} = geo), do: encode_geometry(geo)
+  end
 
   def encode_binary_value(term) when is_list(term) or is_map(term) do
     string = json_library().encode!(term)
@@ -240,10 +242,12 @@ defmodule MyXQL.Protocol.Values do
     raise ArgumentError, "query has invalid parameter #{inspect(other)}"
   end
 
-  defp encode_geometry(geo) do
-    srid = geo.srid || 0
-    binary = %{geo | srid: nil} |> Geo.WKB.encode!(:ndr) |> Base.decode16!()
-    {:mysql_type_geometry, encode_string_lenenc(<<srid::uint4, binary::binary>>)}
+  if Code.ensure_loaded?(Geo) do
+    defp encode_geometry(geo) do
+      srid = geo.srid || 0
+      binary = %{geo | srid: nil} |> Geo.WKB.encode!(:ndr) |> Base.decode16!()
+      {:mysql_type_geometry, encode_string_lenenc(<<srid::uint4, binary::binary>>)}
+    end
   end
 
   ## Time/DateTime
@@ -389,10 +393,22 @@ defmodule MyXQL.Protocol.Values do
     Enum.reverse(acc)
   end
 
-  # https://dev.mysql.com/doc/refman/8.0/en/gis-data-formats.html#gis-internal-format
-  defp decode_geometry(<<srid::uint4, r::bits>>) do
-    srid = if srid == 0, do: nil, else: srid
-    r |> Base.encode16() |> Geo.WKB.decode!() |> Map.put(:srid, srid)
+  if Code.ensure_loaded?(Geo) do
+    # https://dev.mysql.com/doc/refman/8.0/en/gis-data-formats.html#gis-internal-format
+    defp decode_geometry(<<srid::uint4, r::bits>>) do
+      srid = if srid == 0, do: nil, else: srid
+      r |> Base.encode16() |> Geo.WKB.decode!() |> Map.put(:srid, srid)
+    end
+  else
+    defp decode_geometry(_) do
+      raise """
+      encoding/decoding geometry types requires :geo package, add:
+
+          {:geo, "~> 3.3"}
+
+      to your mix.exs and run `mix deps.compile --force myxql`.
+      """
+    end
   end
 
   defp decode_int1(<<v::int1, r::bits>>, null_bitmap, t, acc),

mix.exs

@@ -51,7 +51,7 @@ defmodule MyXQL.MixProject do
       {:db_connection, "~> 2.0", db_connection_opts()},
       {:decimal, "~> 1.6"},
       {:jason, "~> 1.0", optional: true},
-      {:geo, "~> 3.3"},
+      {:geo, "~> 3.3", optional: true},
       {:binpp, ">= 0.0.0", only: [:dev, :test]},
       {:dialyxir, "~> 1.0-rc", only: :dev, runtime: false},
       {:ex_doc, ">= 0.0.0", only: :dev, runtime: false},