%% -*- 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([new/4, list_templates/1]). %% API for other utilities that need templating functionality -export([resolve_variables/2, render/2]). -include("rebar.hrl"). -define(TEMPLATE_RE, "^[^._].*\\.template\$"). -define(ERLYDTL_COMPILE_OPTS, [report_warnings, return_errors, {auto_escape, false}, {out_dir, false}]). %% =================================================================== %% Public API %% =================================================================== %% Apply a template new(Template, Vars, Force, State) -> {AvailTemplates, Files} = find_templates(State), ?DEBUG("Looking for ~p~n", [Template]), case lists:keyfind(Template, 1, AvailTemplates) of false -> {not_found, Template}; TemplateTup -> create(TemplateTup, Files, Vars, Force) end. %% Give a list of templates with their expanded content list_templates(State) -> {AvailTemplates, Files} = find_templates(State), [list_template(Files, Template) || Template <- AvailTemplates]. %% =================================================================== %% Rendering API / legacy? %% =================================================================== %% Given a list of key value pairs, for each string value attempt to %% render it using Dict as the context. Storing the result in Dict as Key. %% resolve_variables([], Dict) -> Dict; resolve_variables([{Key, Value0} | Rest], Dict) when is_list(Value0) -> Value = render(Value0, Dict), resolve_variables(Rest, dict:store(Key, Value, Dict)); resolve_variables([{Key, {list, Dicts}} | Rest], Dict) when is_list(Dicts) -> %% just un-tag it so erlydtl can use it resolve_variables(Rest, dict:store(Key, Dicts, Dict)); resolve_variables([_Pair | Rest], Dict) -> resolve_variables(Rest, Dict). %% %% Render a binary to a string, using erlydtl and the specified context %% render(Template, Context) when is_atom(Template) -> Template:render(Context); render(Template, Context) -> Module = list_to_atom(Template++"_dtl"), Module:render(Context). %% =================================================================== %% Internal Functions %% =================================================================== %% Expand a single template's value list_template(Files, {Name, Type, File}) -> TemplateTerms = consult(load_file(Files, Type, File)), {Name, Type, File, get_template_description(TemplateTerms), get_template_vars(TemplateTerms)}. %% Load up the template description out from a list of attributes read in %% a .template file. get_template_description(TemplateTerms) -> case lists:keyfind(description, 1, TemplateTerms) of {_, Desc} -> Desc; false -> undefined end. %% Load up the variables out from a list of attributes read in a .template file %% and return them merged with the globally-defined and default variables. get_template_vars(TemplateTerms) -> Vars = case lists:keyfind(variables, 1, TemplateTerms) of {_, Value} -> Value; false -> [] end, override_vars(Vars, override_vars(global_variables(), default_variables())). %% Provide a way to merge a set of variables with another one. The left-hand %% set of variables takes precedence over the right-hand set. %% In the case where left-hand variable description contains overriden defaults, but %% the right-hand one contains additional data such as documentation, the resulting %% variable description will contain the widest set of information possible. override_vars([], General) -> General; override_vars([{Var, Default} | Rest], General) -> case lists:keytake(Var, 1, General) of {value, {Var, _Default, Doc}, NewGeneral} -> [{Var, Default, Doc} | override_vars(Rest, NewGeneral)]; {value, {Var, _Default}, NewGeneral} -> [{Var, Default} | override_vars(Rest, NewGeneral)]; false -> [{Var, Default} | override_vars(Rest, General)] end; override_vars([{Var, Default, Doc} | Rest], General) -> [{Var, Default, Doc} | override_vars(Rest, lists:keydelete(Var, 1, General))]. %% Default variables, generated dynamically. default_variables() -> {{Y,M,D},{H,Min,S}} = calendar:universal_time(), [{date, lists:flatten(io_lib:format("~4..0w-~2..0w-~2..0w",[Y,M,D]))}, {datetime, lists:flatten(io_lib:format("~4..0w-~2..0w-~2..0wT~2..0w:~2..0w:~2..0w+00:00",[Y,M,D,H,Min,S]))}, {author_name, "Anonymous"}, {author_email, "anonymous@example.org"}, {copyright_year, integer_to_list(Y)}, {apps_dir, "apps", "Directory where applications will be created if needed"}]. %% Load variable definitions from the 'Globals' file in the home template %% directory global_variables() -> Home = rebar_utils:home_dir(), GlobalFile = filename:join([Home, ?CONFIG_DIR, "templates", "globals"]), case file:consult(GlobalFile) of {error, enoent} -> []; {ok, Data} -> proplists:get_value(variables, Data, []) end. %% drop the documentation for variables when present drop_var_docs([]) -> []; drop_var_docs([{K,V,_}|Rest]) -> [{K,V} | drop_var_docs(Rest)]; drop_var_docs([{K,V}|Rest]) -> [{K,V} | drop_var_docs(Rest)]. %% Load the template index, resolve all variables, and then execute %% the template. create({Template, Type, File}, Files, UserVars, Force) -> TemplateTerms = consult(load_file(Files, Type, File)), Vars = drop_var_docs(override_vars(UserVars, get_template_vars(TemplateTerms))), TemplateCwd = filename:dirname(File), execute_template(TemplateTerms, Files, {Template, Type, TemplateCwd}, Vars, Force). %% Run template instructions one at a time. execute_template([], _, {Template,_,_}, _, _) -> ?DEBUG("Template ~s applied~n", [Template]), ok; %% We can't execute the description execute_template([{description, _} | Terms], Files, Template, Vars, Force) -> execute_template(Terms, Files, Template, Vars, Force); %% We can't execute variables execute_template([{variables, _} | Terms], Files, Template, Vars, Force) -> execute_template(Terms, Files, Template, Vars, Force); %% Create a directory execute_template([{dir, Path} | Terms], Files, Template, Vars, Force) -> ?DEBUG("Creating directory ~p~n", [Path]), case ec_file:mkdir_p(expand_path(Path, Vars)) of ok -> ok; {error, Reason} -> ?ABORT("Failed while processing template instruction " "{dir, ~p}: ~p~n", [Path, Reason]) end, execute_template(Terms, Files, Template, Vars, Force); %% Change permissions on a file execute_template([{chmod, File, Perm} | Terms], Files, Template, Vars, Force) -> Path = expand_path(File, Vars), case file:change_mode(Path, Perm) of ok -> execute_template(Terms, Files, Template, Vars, Force); {error, Reason} -> ?ABORT("Failed while processing template instruction " "{chmod, ~.8#, ~p}: ~p~n", [Perm, File, Reason]) end; %% Create a raw untemplated file execute_template([{file, From, To} | Terms], Files, {Template, Type, Cwd}, Vars, Force) -> ?DEBUG("Creating file ~p~n", [To]), Data = load_file(Files, Type, filename:join(Cwd, From)), Out = expand_path(To,Vars), case write_file(Out, Data, Force) of ok -> ok; {error, exists} -> ?INFO("File ~p already exists.~n", [Out]) end, execute_template(Terms, Files, {Template, Type, Cwd}, Vars, Force); %% Operate on a django template execute_template([{template, From, To} | Terms], Files, {Template, Type, Cwd}, Vars, Force) -> ?DEBUG("Executing template file ~p~n", [From]), Out = expand_path(To, Vars), Tpl = load_file(Files, Type, filename:join(Cwd, From)), TplName = make_template_name("rebar_template", Out), {ok, Mod} = erlydtl:compile_template(Tpl, TplName, ?ERLYDTL_COMPILE_OPTS), {ok, Output} = Mod:render(Vars), case write_file(Out, Output, Force) of ok -> ok; {error, exists} -> ?INFO("File ~p already exists~n", [Out]) end, execute_template(Terms, Files, {Template, Type, Cwd}, Vars, Force); %% Unknown execute_template([Instruction|Terms], Files, Tpl={Template,_,_}, Vars, Force) -> ?WARN("Unknown template instruction ~p in template ~s", [Instruction, Template]), execute_template(Terms, Files, Tpl, Vars, Force). %% Workaround to allow variable substitution in path names without going %% through the ErlyDTL compilation step. Parse the string and replace %% as we go. expand_path([], _) -> []; expand_path("{{"++Rest, Vars) -> replace_var(Rest, [], Vars); expand_path([H|T], Vars) -> [H | expand_path(T, Vars)]. %% Actual variable replacement. replace_var("}}"++Rest, Acc, Vars) -> Var = lists:reverse(Acc), Val = proplists:get_value(list_to_atom(Var), Vars, ""), Val ++ expand_path(Rest, Vars); replace_var([H|T], Acc, Vars) -> replace_var(T, [H|Acc], Vars). %% Load a list of all the files in the escript and on disk find_templates(State) -> %% Cache the files since we'll potentially need to walk it several times %% over the course of a run. Files = cache_escript_files(State), %% Build a list of available templates AvailTemplates = prioritize_templates( tag_names(find_disk_templates(State)), tag_names(find_escript_templates(Files))), ?DEBUG("Available templates: ~p\n", [AvailTemplates]), {AvailTemplates, Files}. %% Scan the current escript for available files cache_escript_files(State) -> {ok, Files} = rebar_utils:escript_foldl( fun(Name, _, GetBin, Acc) -> [{Name, GetBin()} | Acc] end, [], rebar_state:get(State, escript)), Files. %% Find all the template indexes hiding in the rebar3 escript. find_escript_templates(Files) -> [{escript, Name} || {Name, _Bin} <- Files, re:run(Name, ?TEMPLATE_RE, [{capture, none}]) == match]. %% Fetch template indexes that sit on disk in the user's HOME find_disk_templates(State) -> OtherTemplates = find_other_templates(State), Home = rebar_utils:home_dir(), HomeFiles = rebar_utils:find_files(filename:join([Home, ?CONFIG_DIR, "templates"]), ?TEMPLATE_RE), [{file, F} || F <- OtherTemplates ++ HomeFiles]. %% Fetch template indexes that sit on disk in custom areas find_other_templates(State) -> case rebar_state:get(State, template_dir, undefined) of undefined -> []; TemplateDir -> rebar_utils:find_files(TemplateDir, ?TEMPLATE_RE) end. %% Take an existing list of templates and tag them by name the way %% the user would enter it from the CLI tag_names(List) -> [{filename:basename(File, ".template"), Type, File} || {Type, File} <- List]. %% If multiple templates share the same name, those in the escript (built-in) %% take precedence. Otherwise, the on-disk order is the one to win. prioritize_templates([], Acc) -> Acc; prioritize_templates([{Name, Type, File} | Rest], Valid) -> case lists:keyfind(Name, 1, Valid) of false -> prioritize_templates(Rest, [{Name, Type, File} | Valid]); {_, escript, _} -> ?DEBUG("Skipping template ~p, due to presence of a built-in " "template with the same name~n", [Name]), prioritize_templates(Rest, Valid); {_, file, _} -> ?DEBUG("Skipping template ~p, due to presence of a custom " "template at ~s~n", [File]), prioritize_templates(Rest, Valid) end. %% Read the contents of a file from the appropriate source load_file(Files, escript, Name) -> {Name, Bin} = lists:keyfind(Name, 1, Files), Bin; load_file(_Files, file, Name) -> {ok, Bin} = file:read_file(Name), Bin. %% Given a string or binary, parse it into a list of terms, ala file:consult/1 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. write_file(Output, Data, Force) -> %% determine if the target file already exists FileExists = filelib:is_regular(Output), %% perform the function if we're allowed, %% otherwise just process the next template case Force orelse FileExists =:= false of true -> ok = filelib:ensure_dir(Output), case {Force, FileExists} of {true, true} -> ?INFO("Writing ~s (forcibly overwriting)", [Output]); _ -> ?INFO("Writing ~s", [Output]) end, case file:write_file(Output, Data) of ok -> ok; {error, Reason} -> ?ABORT("Failed to write output file ~p: ~p\n", [Output, Reason]) end; false -> {error, exists} end. -spec make_template_name(string(), term()) -> module(). make_template_name(Base, Value) -> %% Seed so we get different values each time random:seed(erlang:now()), Hash = erlang:phash2(Value), Ran = random:uniform(10000000), erlang:list_to_atom(Base ++ "_" ++ erlang:integer_to_list(Hash) ++ "_" ++ erlang:integer_to_list(Ran)).