add lua api to read [resource]

src/play_controller.cpp

@@ -97,7 +97,9 @@ static void copy_persistent(const config& src, config& dst)
 			"remove_from_carryover_on_defeat",
 			"disallow_recall",
 			"experience_modifier",
-			"require_scenario"};
+			"require_scenario",
+			"loaded_resources"
+	};
 
 	static const std::set<std::string> tags {
 			"terrain_graphics",

src/play_controller.hpp

@@ -241,6 +241,11 @@ class play_controller : public controller_base, public events::observer, public
 		return level_["disallow_recall"].to_bool();
 	}
 
+	std::string get_loaded_resources() const
+	{
+		return level_["loaded_resources"].str();
+	}
+
 	std::string theme() const
 	{
 		return gamestate_->get_game_data()->get_theme();

src/saved_game.cpp

@@ -398,6 +398,7 @@ void saved_game::expand_mp_events()
 			}
 		}
 		this->starting_point_["has_mod_events"] = true;
+		this->starting_point_["loaded_resources"] = utils::join(loaded_resources);
 	}
 }
 

src/scripting/game_lua_kernel.cpp

@@ -1314,6 +1314,25 @@ int game_lua_kernel::intf_get_selected_tile(lua_State *L)
 	return 2;
 }
 
+
+/**
+ * Gets a table for an resource tag.
+ * - Arg 1: userdata (ignored).
+ * - Arg 2: string containing id of the desired resource
+ * - Ret 1: config for the era
+ */
+static int intf_get_resource(lua_State *L)
+{
+	std::string m = luaL_checkstring(L, 1);
+	if(const config& res = game_config_manager::get()->game_config().find_child("resource","id",m)) {
+		luaW_pushconfig(L, res);
+		return 1;
+	}
+	else {
+		return luaL_argerror(L, 1, ("Cannot find ressource with id '" + m + "'").c_str());
+	}
+}
+
 /**
  * Gets a table for an era tag.
  * - Arg 1: userdata (ignored).
@@ -1346,6 +1365,7 @@ int game_lua_kernel::impl_game_config_get(lua_State *L)
 	return_string_attrib("scenario_id", gamedata().get_id());
 	return_vector_string_attrib("defeat_music", gamedata().get_defeat_music());
 	return_vector_string_attrib("victory_music", gamedata().get_victory_music());
+	return_vector_string_attrib("active_resources", utils::split(play_controller_.get_loaded_resources()) );
 
 	const mp_game_settings& mp_settings = play_controller_.get_mp_settings();
 	const game_classification & classification = play_controller_.get_classification();
@@ -4179,6 +4199,7 @@ game_lua_kernel::game_lua_kernel(game_state & gs, play_controller & pc, reports
 		{ "create_animator",          &dispatch<&game_lua_kernel::intf_create_animator>          },
 		{ "eval_conditional",         &intf_eval_conditional         },
 		{ "get_era",                  &intf_get_era                  },
+		{ "get_resource",             &intf_get_resource             },
 		{ "get_traits",               &intf_get_traits               },
 		{ "get_viewing_side",         &intf_get_viewing_side         },
 		{ "invoke_synced_command",    &intf_invoke_synced_command    },