add exported_column with its type

Co-authored-by: mfo <mfo@users.noreply.github.com>

app/models/exported_column.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+class ExportedColumn
+  attr_reader :column, :libelle
+
+  def initialize(column:, libelle:)
+    @column = column
+    @libelle = libelle
+  end
+
+  def id = { id: column.id, libelle: }.to_json
+end

app/types/exported_column_type.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+class ExportedColumnType < ActiveRecord::Type::Value
+  # form_input or setter -> type
+  def cast(value)
+    value = value.deep_symbolize_keys if value.respond_to?(:deep_symbolize_keys)
+
+    case value
+    in ExportedColumn
+      value
+    in NilClass # default value
+      nil
+    # from db
+    in { id: String|Hash, libelle: String } => h
+      ExportedColumn.new(column: ColumnType.new.cast(h[:id]), libelle: h[:libelle])
+    # from form
+    in String
+      h = JSON.parse(value).deep_symbolize_keys
+      ExportedColumn.new(column: ColumnType.new.cast(h[:id]), libelle: h[:libelle])
+    end
+  end
+
+  # db -> ruby
+  def deserialize(value) = cast(value&.then { JSON.parse(_1) })
+
+  # ruby -> db
+  def serialize(value)
+    case value
+    in NilClass
+      nil
+    in ExportedColumn
+      JSON.generate({
+        id: value.column.h_id,
+        libelle: value.libelle
+      })
+    else
+      raise ArgumentError, "Invalid value for ExportedColumn serialization: #{value}"
+    end
+  end
+end

config/initializers/types.rb

@@ -4,10 +4,12 @@ require Rails.root.join("app/types/column_type")
 require Rails.root.join("app/types/export_item_type")
 require Rails.root.join("app/types/sorted_column_type")
 require Rails.root.join("app/types/filtered_column_type")
+require Rails.root.join("app/types/exported_column_type")
 
 ActiveSupport.on_load(:active_record) do
   ActiveRecord::Type.register(:column, ColumnType)
   ActiveRecord::Type.register(:export_item, ExportItemType)
   ActiveRecord::Type.register(:sorted_column, SortedColumnType)
   ActiveRecord::Type.register(:filtered_column, FilteredColumnType)
+  ActiveRecord::Type.register(:exported_column, ExportedColumnType)
 end