| % Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| % use this file except in compliance with the License. You may obtain a copy of |
| % the License at |
| % |
| % http://www.apache.org/licenses/LICENSE-2.0 |
| % |
| % Unless required by applicable law or agreed to in writing, software |
| % distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| % WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| % License for the specific language governing permissions and limitations under |
| % the License. |
| |
| -module(config_listener). |
| |
| -behaviour(gen_event). |
| -vsn(2). |
| |
| %% Public interface |
| -export([start/2]). |
| -export([start/3]). |
| |
| %% Required gen_event interface |
| -export([ |
| init/1, |
| handle_event/2, |
| handle_call/2, |
| handle_info/2, |
| terminate/2, |
| code_change/3 |
| ]). |
| |
| -callback handle_config_change( |
| Sec :: string(), |
| Key :: string(), |
| Value :: string(), |
| Persist :: boolean(), |
| State :: term() |
| ) -> |
| {ok, term()} | remove_handler. |
| |
| -callback handle_config_terminate( |
| Subscriber :: pid(), |
| Reason :: term(), |
| State :: term() |
| ) -> |
| term(). |
| |
| start(Module, State) -> |
| start(Module, Module, State). |
| |
| start(Module, Id, State) -> |
| gen_event:add_sup_handler(config_event, {?MODULE, Id}, {Module, State}). |
| |
| init({Module, State}) -> |
| {ok, {Module, State}}. |
| |
| handle_event({config_change, Sec, Key, Value, Persist}, {Module, {From, State}}) -> |
| case Module:handle_config_change(Sec, Key, Value, Persist, State) of |
| {ok, NewState} -> |
| {ok, {Module, {From, NewState}}}; |
| remove_handler -> |
| remove_handler |
| end. |
| |
| handle_call(_Request, St) -> |
| {ok, ignored, St}. |
| |
| handle_info(_Info, St) -> |
| {ok, St}. |
| |
| terminate(Reason, {Module, {Subscriber, State}}) -> |
| Module:handle_config_terminate(Subscriber, Reason, State). |
| |
| code_change(_OldVsn, St, _Extra) -> |
| {ok, St}. |