These are the full templates for gen_server, supervisor, and application from the Emacs mode for Erlang. Some pieces are more useful than others, but seeing the full set of expected responses can be useful.
Note
Remember, the noreply atom doesn’t mean “there will never be a reply” but rather that “this response isn’t a reply.”
Example B-1. A gen_server template from the Erlang mode for Emacs
%%%-------------------------------------------------------------------%%% @author $author%%% @copyright (C) $year, $company%%% @doc%%%%%% @end%%% Created : $fulldate%%%--------------------------------------------------------------------module($basename).-behaviour(gen_server).%% API-export([start_link/0]).%% gen_server callbacks-export([init/1,handle_call/3,handle_cast/2,handle_info/2,terminate/2,code_change/3]).-define(SERVER,?MODULE).-record(state,{}).%%%===================================================================%%% API%%%===================================================================%%--------------------------------------------------------------------%% @doc%% Starts the server%%%% @spec start_link() -> {ok, Pid} | ignore | {error, Error}%% @end%%--------------------------------------------------------------------start_link()->gen_server:start_link({local,?SERVER},?MODULE,[],[]).%%%===================================================================%%% gen_server callbacks%%%===================================================================%%--------------------------------------------------------------------%% @private%% @doc%% Initializes the server%%%% @spec init(Args) -> {ok, State} |%% {ok, State, Timeout} |%% ignore |%% {stop, Reason}%% @end%%--------------------------------------------------------------------init([])->{ok,#state{}}.%%--------------------------------------------------------------------%% @private%% @doc%% Handling call messages%%%% @spec handle_call(Request, From, State) ->%% {reply, Reply, State} |%% {reply, Reply, State, Timeout} |%% {noreply, State} |%% {noreply, State, Timeout} |%% {stop, Reason, Reply, State} |%% {stop, Reason, State}%% @end%%--------------------------------------------------------------------handle_call(_Request,_From,State)->Reply=ok,{reply,Reply,State}.%%--------------------------------------------------------------------%% @private%% @doc%% Handling cast messages%%%% @spec handle_cast(Msg, State) -> {noreply, State} |%% {noreply, State, Timeout} |%% {stop, Reason, State}%% @end%%--------------------------------------------------------------------handle_cast(_Msg,State)->{noreply,State}.%%--------------------------------------------------------------------%% @private%% @doc%% Handling all non call/cast messages%%%% @spec handle_info(Info, State) -> {noreply, State} |%% {noreply, State, Timeout} |%% {stop, Reason, State}%% @end%%--------------------------------------------------------------------handle_info(_Info,State)->{noreply,State}.%%--------------------------------------------------------------------%% @private%% @doc%% This function is called by a gen_server when it is about to%% terminate. It should be the opposite of Module:init/1 and do any%% necessary cleaning up. When it returns, the gen_server terminates%% with Reason. The return value is ignored.%%%% @spec terminate(Reason, State) -> void()%% @end%%--------------------------------------------------------------------terminate(_Reason,_State)->ok.%%--------------------------------------------------------------------%% @private%% @doc%% Convert process state when code is changed%%%% @spec code_change(OldVsn, State, Extra) -> {ok, NewState}%% @end%%--------------------------------------------------------------------code_change(_OldVsn,State,_Extra)->{ok,State}.%%%===================================================================%%% Internal functions%%%===================================================================
Example B-2. A supervisor template from the Erlang mode for Emacs
%%%-------------------------------------------------------------------%%% @author $author%%% @copyright (C) $year, $company%%% @doc%%%%%% @end%%% Created : $fulldate%%%--------------------------------------------------------------------module($basename).-behaviour(supervisor).%% API-export([start_link/0]).%% Supervisor callbacks-export([init/1]).-define(SERVER,?MODULE).%%%===================================================================%%% API functions%%%===================================================================%%--------------------------------------------------------------------%% @doc%% Starts the supervisor%%%% @spec start_link() -> {ok, Pid} | ignore | {error, Error}%% @end%%--------------------------------------------------------------------start_link()->supervisor:start_link({local,?SERVER},?MODULE,[]).%%%===================================================================%%% Supervisor callbacks%%%===================================================================%%--------------------------------------------------------------------%% @private%% @doc%% Whenever a supervisor is started using supervisor:start_link/[2,3],%% this function is called by the new process to find out about%% restart strategy, maximum restart frequency and child%% specifications.%%%% @spec init(Args) -> {ok, {SupFlags, [ChildSpec]}} |%% ignore |%% {error, Reason}%% @end%%--------------------------------------------------------------------init([])->RestartStrategy=one_for_one,MaxRestarts=1000,MaxSecondsBetweenRestarts=3600,SupFlags={RestartStrategy,MaxRestarts,MaxSecondsBetweenRestarts},Restart=permanent,Shutdown=2000,Type=worker,AChild={'AName',{'AModule',start_link,[]},Restart,Shutdown,Type,['AModule']},{ok,{SupFlags,[AChild]}}.%%%===================================================================%%% Internal functions%%%===================================================================
Example B-3. An application module template from the Erlang mode for Emacs
%%%-------------------------------------------------------------------%%% @author $author%%% @copyright (C) $year, $company%%% @doc%%%%%% @end%%% Created : $fulldate%%%--------------------------------------------------------------------module($basename).-behaviour(application).%% Application callbacks-export([start/2,stop/1]).%%%===================================================================%%% Application callbacks%%%===================================================================%%--------------------------------------------------------------------%% @private%% @doc%% This function is called whenever an application is started using%% application:start/[1,2], and should start the processes of the%% application. If the application is structured according to the OTP%% design principles as a supervision tree, this means starting the%% top supervisor of the tree.%%%% @spec start(StartType, StartArgs) -> {ok, Pid} |%% {ok, Pid, State} |%% {error, Reason}%% StartType = normal | {takeover, Node} | {failover, Node}%% StartArgs = term()%% @end%%--------------------------------------------------------------------start(_StartType,_StartArgs)->case'TopSupervisor':start_link()of{ok,Pid}->{ok,Pid};Error->Errorend.%%--------------------------------------------------------------------%% @private%% @doc%% This function is called whenever an application has stopped. It%% is intended to be the opposite of Module:start/2 and should do%% any necessary cleaning up. The return value is ignored.%%%% @spec stop(State) -> void()%% @end%%--------------------------------------------------------------------stop(_State)->ok.%%%===================================================================%%% Internal functions%%%===================================================================
..................Content has been hidden....................
You can't read the all page of ebook, please click here login for view all page.