diff --git a/src/lager_common_test_backend.erl b/src/lager_common_test_backend.erl new file mode 100644 index 0000000..156eef3 --- /dev/null +++ b/src/lager_common_test_backend.erl @@ -0,0 +1,133 @@ +-module(lager_common_test_backend). + +-behavior(gen_event). + +%% gen_event callbacks +-export([init/1, + handle_call/2, + handle_event/2, + handle_info/2, + terminate/2, + code_change/3]). +-export([get_logs/0, + bounce/0, + bounce/1]). + +%% holds the log messages for retreival on terminate +-record(state, {level :: {mask, integer()}, + verbose :: boolean(), + log = [] :: list()}). + +-include_lib("lager/include/lager.hrl"). + +-spec get_logs() -> [iolist()] | {error, term()}. +get_logs() -> + gen_event:call(lager_event, ?MODULE, get_logs, infinity). + +bounce() -> + bounce(error). + +bounce(Level) -> + application:stop(lager), + lager:start(), + gen_event:add_handler(lager_event, lager_common_test_backend, [error, false]), + lager:set_loglevel(lager_common_test_backend, Level), + ok. + +-spec(init(integer()|atom()|[term()]) -> {ok, #state{}} | {error, atom()}). +%% @private +%% @doc Initializes the event handler +init(Level) when is_atom(Level) -> + case lists:member(Level, ?LEVELS) of + true -> + {ok, #state{level=lager_util:level_to_num(Level), verbose=false}}; + _ -> + {error, bad_log_level} + end; +init([Level, Verbose]) -> + case lists:member(Level, ?LEVELS) of + true -> + {ok, #state{level=lager_util:level_to_num(Level), verbose=Verbose}}; + _ -> + {error, bad_log_level} + end. + +-spec(handle_event(tuple(), #state{}) -> {ok, #state{}}). +%% @private +%% @doc handles the event, adding the log message to the gen_event's state. +%% this function attempts to handle logging events in both the simple tuple +%% and new record (introduced after lager 1.2.1) formats. +handle_event({log, Dest, Level, {Date, Time}, [LevelStr, Location, Message]}, %% lager 1.2.1 + #state{level=L, verbose=Verbose, log = Logs} = State) when Level > L -> + case lists:member(lager_common_test_backend, Dest) of + true -> + Log = case Verbose of + true -> + [Date, " ", Time, " ", LevelStr, Location, Message]; + _ -> + [Time, " ", LevelStr, Message] + end, + ct:pal(Log), + {ok, State#state{log=[Log|Logs]}}; + false -> + {ok, State} + end; +handle_event({log, Level, {Date, Time}, [LevelStr, Location, Message]}, %% lager 1.2.1 + #state{level=LogLevel, verbose=Verbose, log = Logs} = State) when Level =< LogLevel -> + Log = case Verbose of + true -> + [Date, " ", Time, " ", LevelStr, Location, Message]; + _ -> + [Time, " ", LevelStr, Message] + end, + ct:pal(Log), + {ok, State#state{log=[Log|Logs]}}; +handle_event({log, {lager_msg, Dest, _Meta, Level, DateTime, _Timestamp, Message}}, + State) -> %% lager 2.0.0 + case lager_util:level_to_num(Level) of + L when L =< State#state.level -> + handle_event({log, L, DateTime, + [["[",atom_to_list(Level),"] "], " ", Message]}, + State); + L -> + handle_event({log, Dest, L, DateTime, + [["[",atom_to_list(Level),"] "], " ", Message]}, + State) + end; +handle_event(Event, State) -> + ct:pal(Event), + {ok, State#state{log = [Event|State#state.log]}}. + +-spec(handle_call(any(), #state{}) -> {ok, any(), #state{}}). +%% @private +%% @doc gets and sets loglevel. This is part of the lager backend api. +handle_call(get_loglevel, #state{level=Level} = State) -> + {ok, Level, State}; +handle_call({set_loglevel, Level}, State) -> + case lists:member(Level, ?LEVELS) of + true -> + {ok, ok, State#state{level=lager_util:level_to_num(Level)}}; + _ -> + {ok, {error, bad_log_level}, State} + end; +handle_call(get_logs, #state{log = Logs} = State) -> + {ok, lists:reverse(Logs), State}; +handle_call(_, State) -> + {ok, ok, State}. + +-spec(handle_info(any(), #state{}) -> {ok, #state{}}). +%% @private +%% @doc gen_event callback, does nothing. +handle_info(_, State) -> + {ok, State}. + +-spec(code_change(any(), #state{}, any()) -> {ok, #state{}}). +%% @private +%% @doc gen_event callback, does nothing. +code_change(_OldVsn, State, _Extra) -> + {ok, State}. + +-spec(terminate(any(), #state{}) -> {ok, list()}). +%% @doc gen_event callback, does nothing. +terminate(_Reason, #state{log=Logs}) -> + {ok, lists:reverse(Logs)}.