%% -*- tab-width: 4;erlang-indent-level: 4;indent-tabs-mode: nil -*- %% ex: ts=4 sw=4 et %% ------------------------------------------------------------------- %% %% rebar: Erlang Build Tools %% %% Copyright (c) 2009 Dave Smith (dizzyd@dizzyd.com) %% %% Permission is hereby granted, free of charge, to any person obtaining a copy %% of this software and associated documentation files (the "Software"), to deal %% in the Software without restriction, including without limitation the rights %% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell %% copies of the Software, and to permit persons to whom the Software is %% furnished to do so, subject to the following conditions: %% %% The above copyright notice and this permission notice shall be included in %% all copies or substantial portions of the Software. %% %% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR %% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, %% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE %% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER %% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, %% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN %% THE SOFTWARE. %% ------------------------------------------------------------------- -module(rebar_templater). -export(['create-app'/2, 'create-node'/2, create/2]). -include("rebar.hrl"). -define(TEMPLATE_RE, ".*\\.template\$"). %% =================================================================== %% Public API %% =================================================================== 'create-app'(Config, File) -> %% Alias for create w/ template=simpleapp rebar_config:set_global(template, "simpleapp"), create(Config, File). 'create-node'(Config, File) -> %% Alias for create w/ template=simplenode rebar_config:set_global(template, "simplenode"), create(Config, File). create(_Config, _) -> %% Load a list of all the files in the escript -- cache it in the pdict %% since we'll potentially need to walk it several times over the course %% of a run. cache_escript_files(), %% Build a list of available templates AvailTemplates = find_disk_templates() ++ find_escript_templates(), ?DEBUG("Available templates: ~p\n", [AvailTemplates]), %% Using the specified template id, find the matching template file/type. %% Note that if you define the same template in both ~/.rebar/templates %% that is also present in the escript, the one on the file system will %% be preferred. {Type, Template} = select_template(AvailTemplates, template_id()), %% Load the template definition as is and get the list of variables the %% template requires. TemplateTerms = consult(load_file(Type, Template)), case lists:keysearch(variables, 1, TemplateTerms) of {value, {variables, Vars}} -> case parse_vars(Vars, dict:new()) of {error, Entry} -> Context0 = undefined, ?ABORT("Failed while processing variables from template ~p. Variable definitions " "must follow form of [{atom(), term()}]. Failed at: ~p\n", [template_id(), Entry]); Context0 -> ok end; false -> ?WARN("No variables section found in template ~p; using empty context.\n", [template_id()]), Context0 = dict:new() end, %% For each variable, see if it's defined in global vars -- if it is, prefer that %% value over the defaults Context = update_vars(dict:fetch_keys(Context0), Context0), ?DEBUG("Template ~p context: ~p\n", [template_id(), dict:to_list(Context)]), %% Now, use our context to process the template definition -- this permits us to %% use variables within the definition for filenames. FinalTemplate = consult(render(load_file(Type, Template), Context)), ?DEBUG("Final template def ~p: ~p\n", [template_id(), FinalTemplate]), %% Execute the instructions in the finalized template Force = rebar_config:get_global(force, "0"), execute_template(FinalTemplate, Type, Template, Context, Force, []). %% =================================================================== %% Internal functions %% =================================================================== %% %% Scan the current escript for available files and cache in pdict. %% cache_escript_files() -> {ok, Files} = escript:foldl(fun(Name, _, GetBin, Acc) -> [{Name, GetBin()} | Acc] end, [], escript:script_name()), erlang:put(escript_files, Files). template_id() -> case rebar_config:get_global(template, undefined) of undefined -> ?ABORT("No template specified.\n", []); TemplateId -> TemplateId end. find_escript_templates() -> [{escript, Name} || {Name, _Bin} <- erlang:get(escript_files), re:run(Name, ?TEMPLATE_RE, [{capture, none}]) == match]. find_disk_templates() -> Files = rebar_utils:find_files(filename:join(os:getenv("HOME"), ".rebar/templates"), ?TEMPLATE_RE), [{file, F} || F <- Files]. select_template([], Template) -> ?ABORT("Template ~s not found.\n", [Template]); select_template([{Type, Avail} | Rest], Template) -> case filename:basename(Avail, ".template") == Template of true -> {Type, Avail}; false -> select_template(Rest, Template) end. %% %% Read the contents of a file from the appropriate source %% load_file(escript, Name) -> {Name, Bin} = lists:keyfind(Name, 1, erlang:get(escript_files)), Bin; load_file(file, Name) -> {ok, Bin} = file:read_file(Name), Bin. %% %% Parse/validate variables out from the template definition %% parse_vars([], Dict) -> Dict; parse_vars([{Key, Value} | Rest], Dict) when is_atom(Key) -> parse_vars(Rest, dict:store(Key, Value, Dict)); parse_vars([Other | _Rest], _Dict) -> {error, Other}; parse_vars(Other, _Dict) -> {error, Other}. %% %% Given a list of keys in Dict, see if there is a corresponding value defined %% in the global config; if there is, update the key in Dict with it %% update_vars([], Dict) -> Dict; update_vars([Key | Rest], Dict) -> Value = rebar_config:get_global(Key, dict:fetch(Key, Dict)), update_vars(Rest, dict:store(Key, Value, Dict)). %% %% Given a string or binary, parse it into a list of terms, ala file:consult/0 %% consult(Str) when is_list(Str) -> consult([], Str, []); consult(Bin) when is_binary(Bin)-> consult([], binary_to_list(Bin), []). consult(Cont, Str, Acc) -> case erl_scan:tokens(Cont, Str, 0) of {done, Result, Remaining} -> case Result of {ok, Tokens, _} -> {ok, Term} = erl_parse:parse_term(Tokens), consult([], Remaining, [Term | Acc]); {eof, _Other} -> lists:reverse(Acc); {error, Info, _} -> {error, Info} end; {more, Cont1} -> consult(Cont1, eof, Acc) end. %% %% Render a binary to a string, using mustache and the specified context %% render(Bin, Context) -> %% Be sure to escape any double-quotes before rendering... Str = re:replace(Bin, "\"", "\\\\\"", [global, {return,list}]), mustache:render(Str, Context). %% %% Execute each instruction in a template definition file. %% execute_template([], _TemplateType, _TemplateName, _Context, _Force, ExistingFiles) -> case length(ExistingFiles) of 0 -> ok; _ -> Msg = lists:flatten([io_lib:format("\t* ~p~n", [F]) || F <- lists:reverse(ExistingFiles)]), Help = "To force overwriting, specify force=1 on the command line.\n", ?ERROR("One or more files already exist on disk and were not generated:~n~s~s", [Msg , Help]) end; execute_template([{file, Input, Output} | Rest], TemplateType, TemplateName, Context, Force, ExistingFiles) -> % determine if the target file already exists FileExists = filelib:is_file(Output), % perform the function if we're allowed, otherwise just process the next template if Force =:= "1"; FileExists =:= false -> InputName = filename:join(filename:dirname(TemplateName), Input), filelib:ensure_dir(Output), if {Force, FileExists} =:= {"1", true} -> ?CONSOLE("Writing ~s (forcibly overwriting)~n", [Output]); true -> ?CONSOLE("Writing ~s~n", [Output]) end, case file:write_file(Output, render(load_file(TemplateType, InputName), Context)) of ok -> execute_template(Rest, TemplateType, TemplateName, Context, Force, ExistingFiles); {error, Reason} -> ?ABORT("Failed to write output file ~p: ~p\n", [Output, Reason]) end; true -> execute_template(Rest, TemplateType, TemplateName, Context, Force, [Output|ExistingFiles]) end; execute_template([{dir, Name} | Rest], TemplateType, TemplateName, Context, Force, ExistingFiles) -> case filelib:ensure_dir(filename:join(Name, "dummy")) of ok -> execute_template(Rest, TemplateType, TemplateName, Context, Force, ExistingFiles); {error, Reason} -> ?ABORT("Failed while processing template instruction {dir, ~s}: ~p\n", [Name, Reason]) end; execute_template([{variables, _} | Rest], TemplateType, TemplateName, Context, Force, ExistingFiles) -> execute_template(Rest, TemplateType, TemplateName, Context, Force, ExistingFiles); execute_template([Other | Rest], TemplateType, TemplateName, Context, Force, ExistingFiles) -> ?WARN("Skipping unknown template instruction: ~p\n", [Other]), execute_template(Rest, TemplateType, TemplateName, Context, Force, ExistingFiles).