FEATURE: allow registration of an array custom field

app/models/concerns/has_custom_fields.rb

@@ -6,7 +6,7 @@ module HasCustomFields
     def self.append_field(target, key, value, types)
       if target.has_key?(key)
         target[key] = [target[key]] if !target[key].is_a? Array
-        target[key] << cast_custom_field(key, value, types)
+        target[key] << cast_custom_field(key, value, types, _return_array = false)
       else
         target[key] = cast_custom_field(key, value, types)
       end
@@ -28,16 +28,26 @@ module HasCustomFields
       types[key]
     end
 
-    def self.cast_custom_field(key, value, types)
+    def self.cast_custom_field(key, value, types, return_array = true)
       return value unless type = get_custom_field_type(types, key)
 
-      case type
-      when :boolean then !!CUSTOM_FIELD_TRUE.include?(value)
-      when :integer then value.to_i
-      when :json    then ::JSON.parse(value)
-      else
-        value
+      array = nil
+
+      if Array === type
+        type = type[0]
+        array = true if return_array
       end
+
+      result =
+        case type
+        when :boolean then !!CUSTOM_FIELD_TRUE.include?(value)
+        when :integer then value.to_i
+        when :json    then ::JSON.parse(value)
+        else
+          value
+        end
+
+      array ? [result] : result
     end
   end
 

spec/components/concern/has_custom_fields_spec.rb

@@ -98,6 +98,15 @@ describe HasCustomFields do
     end
 
     it "handles arrays properly" do
+
+      CustomFieldsTestItem.register_custom_field_type "array", [:integer]
+      test_item = CustomFieldsTestItem.new
+      test_item.custom_fields = { "array" => ["1"] }
+      test_item.save
+
+      db_item = CustomFieldsTestItem.find(test_item.id)
+      expect(db_item.custom_fields).to eq("array" => [1])
+
       test_item = CustomFieldsTestItem.new
       test_item.custom_fields = { "a" => ["b", "c", "d"] }
       test_item.save