csv export

lib/talon/controller.ex

@@ -86,7 +86,16 @@ defmodule Talon.Controller do # TODO: rename to ResourceController (DJS)
         |> render("search.html", conn: conn)
       end
 
-      defoverridable [index: 2, show: 2, new: 2, edit: 2, create: 2, update: 2, delete: 2, set_repo: 2, search: 2]
+      def csv(conn, _params) do
+        repo = Talon.View.repo(conn)
+        resources = repo.all(conn.assigns.talon.schema)
+        csv_schema = Talon.CSV.normalize_schema(conn.assigns.talon.talon_resource.csv_schema())
+        file_path = Talon.CSV.write_file(resources, csv_schema)
+        file_name = conn.assigns.talon.talon_resource.index_card_title() <> ".csv"
+        send_download(conn, {:file, file_path}, filename: file_name)
+      end
+
+      defoverridable [index: 2, show: 2, new: 2, edit: 2, create: 2, update: 2, delete: 2, set_repo: 2, search: 2, csv: 2]
     end
   end
 

lib/talon/csv.ex

@@ -0,0 +1,45 @@
+defmodule Talon.CSV do
+  @moduledoc """
+  """
+
+  def write_file(resources, schema) do
+    random_name =
+      :crypto.strong_rand_bytes(16)
+      |> Base.url_encode64
+      |> binary_part(0, 16)
+    file_path = System.tmp_dir() <> random_name
+    file = File.open!(file_path, [:write, :utf8])
+    rows = Enum.map(resources, fn(resource) ->
+      build_row(resource, schema)
+    end)
+
+    [build_header(schema) | rows]
+    |> CSV.encode
+    |> Enum.each(&IO.write(file, &1))
+
+    :ok = File.close(file)
+    file_path
+  end
+
+  def normalize_schema(schema) do
+    Enum.map schema, fn
+      {name, fun} -> %{field: name, fun: fun}
+      name when is_atom(name) -> %{field: name, fun: nil}
+      map -> map
+    end
+  end
+
+  defp build_header(schema) do
+    for field <- schema, do: field[:field]
+  end
+
+  defp build_row(resource, schema) do
+    Enum.reduce(schema, [], fn
+      %{field: name, fun: nil}, acc ->
+        [Map.get(resource, name) | acc]
+      %{field: _name, fun: fun}, acc ->
+        [fun.(resource) | acc]
+    end)
+    |> Enum.reverse
+  end
+end

lib/talon/resource.ex

@@ -71,6 +71,10 @@ defmodule Talon.Resource do
         @__module__.__schema__(:fields) -- ~w(id inserted_at updated_at)a
       end
 
+      def csv_schema do
+        @__module__.__schema__(:fields) -- ~w(inserted_at updated_at)a
+      end
+
       @doc """
       Translates column atoms into human title format.
 

mix.exs

@@ -37,6 +37,7 @@ defmodule Talon.Mixfile do
       {:ecto_talon, github: "talonframework/ecto_talon"},
       {:mix_test_watch, "~> 0.3", only: :dev, runtime: false},
       {:gettext, "~> 0.11", only: :test},
+      {:csv, "~> 2.0"},
       {:dialyxir, "~> 0.5.0", only: [:dev]}
       # {:ecto_talon, path: "../ecto_talon", only: :test},
     ]

priv/templates/talon.gen.components/components/datatable/templates/datatable.html.slim

@@ -32,3 +32,5 @@
 
         .box-footer.clear-fix
           = <%= base %>.<%= concern %>.<%= theme_module %>.<%= web_namespace %>PaginateView.paginate(@conn)
+
+      a href="#{talon_resource.route_name}/csv" Download CSV