%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1998-2016. All Rights Reserved.
%%
%% 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.
%%
%% %CopyrightEnd%
%%
%% ----------------------------------------------------------------------
%% Purpose : Starts applications in the phases defined in the .app file's
%% start_phases key. If the application includes other applications
%% these are also started according to their mod and
%% start_phases-keys in their .app file.
%% ----------------------------------------------------------------------
-module(application_starter).
-export([start/3]).
%%%=============================================================================
%%%=============================================================================
%%%=============================================================================
%%% start(Phases, Type, Applications) -> ok | {error, ErrorMessage}
%%%
%%% The applications are started by calling Module:start_phase(Phase, Type, Args)
%%% where Module and is defined in the mod-key, Phase and Args are defined in
%%% the start_phases-key.
%%%=============================================================================
%%%=============================================================================
%%%=============================================================================
start([], _Type, _Apps) ->
ok;
start([{Phase,_PhaseArgs}|Phases], Type, Apps) ->
case start_apps(Phase, Type, Apps) of
{error, _} = Error ->
Error;
_ ->
start(Phases, Type, Apps)
end.
%%%=============================================================================
%%% Start each application in the phase Phase.
%%%=============================================================================
start_apps(_Phase, _Type, []) ->
ok;
start_apps(Phase, Type, [App | Apps]) ->
case catch run_start_phase(Phase, Type, App) of
{error, _} = Error ->
Error;
_ ->
start_apps(Phase, Type, Apps)
end.
%%%=============================================================================
%%% If application_starter is used recursively, start also all the included
%%% applications in the phase Phase.
%%%=============================================================================
run_start_phase(Phase, Type, App) ->
{ok,{Mod,Arg}} = application:get_key(App, mod),
case Mod of
application_starter ->
[StartMod, _StartArgs] = Arg,
run_the_phase(Phase, Type, App, StartMod),
{ok, IncApps} = application:get_key(App, included_applications),
start_apps(Phase, Type, IncApps);
_ ->
run_the_phase(Phase, Type, App, Mod)
end.
%%%=============================================================================
%%% Start the application only if the start phase is defined in the
%%% start_phases-key.
%%%=============================================================================
run_the_phase(Phase, Type, App, Mod) ->
Start_phases = case application_controller:get_key(App, start_phases) of
{ok, undefined} ->
throw({error, {start_phases_undefined, App}});
{ok, Sp} ->
Sp
end,
case lists:keyfind(Phase, 1, Start_phases) of
false ->
ok;
{Phase, PhaseArgs} ->
case catch Mod:start_phase(Phase, Type, PhaseArgs) of
ok ->
ok;
{error, Reason} ->
throw({error, {Reason,
{Mod, start_phase,
[Phase, Type, PhaseArgs]}}});
Other ->
throw({error, {bad_return_value,
{{Mod, start_phase,
[Phase, Type, PhaseArgs]},
Other}}})
end
end.
