Centralize variable resolution; add target_dir variable

src/rebar_reltool.erl

@@ -220,10 +220,13 @@ run_reltool(Server, _Config, ReltoolConfig) ->
 
             %% Initialize overlay vars with some basics
             %% (that can get overwritten)
-            OverlayVars0 = dict:from_list([{erts_vsn, "erts-" ++ erlang:system_info(version)}]),
+            OverlayVars0 = dict:from_list([{erts_vsn, "erts-" ++ erlang:system_info(version)},
+                                           {target_dir, TargetDir}]),
 
             %% Load up any variables specified by overlay_vars
-            OverlayVars = overlay_vars(OverlayVars0, ReltoolConfig),
+            OverlayVars1 = overlay_vars(OverlayVars0, ReltoolConfig),
+            OverlayVars = rebar_templater:resolve_variables(dict:to_list(OverlayVars1),
+                                                            OverlayVars1),
 
             %% Finally, overlay the files specified by the overlay section
             case lists:keyfind(overlay, 1, ReltoolConfig) of
@@ -270,18 +273,20 @@ dump_spec(Spec) ->
     end.
 
 
+%% TODO: Merge functionality here with rebar_templater
+
 execute_overlay([], _Vars, _BaseDir, _TargetDir) ->
     ok;
 execute_overlay([{mkdir, Out} | Rest], Vars, BaseDir, TargetDir) ->
-    OutFile = render(filename:join([TargetDir, Out, "dummy"]), Vars),
+    OutFile = rebar_templater:render(filename:join([TargetDir, Out, "dummy"]), Vars),
     ok = filelib:ensure_dir(OutFile),
     ?DEBUG("Created dir ~s\n", [filename:dirname(OutFile)]),
     execute_overlay(Rest, Vars, BaseDir, TargetDir);
 execute_overlay([{copy, In} | Rest], _Vars, BaseDir, TargetDir) ->
     execute_overlay([{copy, In, ""} | Rest], _Vars, BaseDir, TargetDir);
 execute_overlay([{copy, In, Out} | Rest], Vars, BaseDir, TargetDir) ->
-    InFile = render(filename:join(BaseDir, In), Vars),
+    InFile = rebar_templater:render(filename:join(BaseDir, In), Vars),
-    OutFile = render(filename:join(TargetDir, Out), Vars),
+    OutFile = rebar_templater:render(filename:join(TargetDir, Out), Vars),
     case filelib:is_dir(InFile) of
         true ->
             ok;
@@ -306,11 +311,11 @@ execute_overlay([{template_wildcard, Wildcard, OutDir} | Rest], Vars, BaseDir, T
     ?DEBUG("template_wildcard: ~s expanded to ~p\n", [Wildcard, NewInstrs]),
     execute_overlay(NewInstrs, Vars, BaseDir, TargetDir);
 execute_overlay([{template, In, Out} | Rest], Vars, BaseDir, TargetDir) ->
-    InFile = render(filename:join(BaseDir, In), Vars),
+    InFile = rebar_templater:render(filename:join(BaseDir, In), Vars),
     {ok, InFileData} = file:read_file(InFile),
-    OutFile = render(filename:join(TargetDir, Out), Vars),
+    OutFile = rebar_templater:render(filename:join(TargetDir, Out), Vars),
     ok = filelib:ensure_dir(OutFile),
-    case file:write_file(OutFile, render(InFileData, Vars)) of
+    case file:write_file(OutFile, rebar_templater:render(InFileData, Vars)) of
         ok ->
             ok = apply_file_info(InFile, OutFile),
             ?DEBUG("Templated ~p\n", [OutFile]),
@@ -319,7 +324,7 @@ execute_overlay([{template, In, Out} | Rest], Vars, BaseDir, TargetDir) ->
             ?ABORT("Failed to template ~p: ~p\n", [OutFile, Reason])
     end;
 execute_overlay([{create, Out, Contents} | Rest], Vars, BaseDir, TargetDir) ->
-    OutFile = render(filename:join(TargetDir, Out), Vars),
+    OutFile = rebar_templater:render(filename:join(TargetDir, Out), Vars),
     ok = filelib:ensure_dir(OutFile),
     case file:write_file(OutFile, Contents) of
         ok ->
@@ -334,7 +339,7 @@ execute_overlay([{replace, Out, Regex, Replacement} | Rest],
                     Vars, BaseDir, TargetDir);
 execute_overlay([{replace, Out, Regex, Replacement, Opts} | Rest],
                 Vars, BaseDir, TargetDir) ->
-    Filename = render(filename:join(TargetDir, Out), Vars),
+    Filename = rebar_templater:render(filename:join(TargetDir, Out), Vars),
     {ok, OrigData} = file:read_file(Filename),
     Data = re:replace(OrigData, Regex, Replacement,
                       [global, {return, binary}] ++ Opts),
@@ -349,18 +354,6 @@ execute_overlay([Other | _Rest], _Vars, _BaseDir, _TargetDir) ->
     {error, {unsupported_operation, Other}}.
 
 
-
-%%
-%% Render a binary to a string, using mustache and the specified context
-%%
-render(Bin, Context) ->
-    ReOpts = [global, {return, list}],
-    %% Be sure to escape any double-quotes before rendering...
-    Str0 = re:replace(Bin, "\\\\", "\\\\\\", ReOpts),
-    Str1 = re:replace(Str0, "\"", "\\\\\"", ReOpts),
-    mustache:render(Str1, Context).
-
-
 apply_file_info(InFile, OutFile) ->
     {ok, FileInfo} = file:read_file_info(InFile),
     ok = file:write_file_info(OutFile, FileInfo).

src/rebar_templater.erl

@@ -31,6 +31,10 @@
          'list-templates'/2,
          create/2]).
 
+%% API for other utilities that need templating functionality
+-export([resolve_variables/2,
+         render/2]).
+
 -include("rebar.hrl").
 
 -define(TEMPLATE_RE, ".*\\.template\$").
@@ -127,7 +131,7 @@ create(_Config, _) ->
 
     %% Handle variables that possibly include other variables in their
     %% definition
-    Context = resolve_recursive_vars(dict:to_list(Context2), Context2),
+    Context = resolve_variables(dict:to_list(Context2), Context2),
 
     ?DEBUG("Resolved Template ~p context: ~p\n",
            [TemplateId, dict:to_list(Context)]),
@@ -142,6 +146,28 @@ create(_Config, _) ->
     execute_template(FinalTemplate, Type, Template, Context, Force, []).
 
 
+%%
+%% 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(list_to_binary(Value0), Dict),
+    resolve_variables(Rest, dict:store(Key, Value, Dict));
+resolve_variables([_Pair | Rest], Dict) ->
+    resolve_variables(Rest, Dict).
+
+
+%%
+%% Render a binary to a string, using mustache and the specified context
+%%
+render(Bin, Context) ->
+    %% Be sure to escape any double-quotes before rendering...
+    ReOpts = [global, {return, list}],
+    Str0 = re:replace(Bin, "\\\\", "\\\\\\", ReOpts),
+    Str1 = re:replace(Str0, "\"", "\\\\\"", ReOpts),
+    mustache:render(Str1, Context).
 
 
 %% ===================================================================
@@ -231,18 +257,6 @@ update_vars([Key | Rest], Dict) ->
     update_vars(Rest, dict:store(Key, Value, Dict)).
 
 
-%%
-%% 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_recursive_vars([], Dict) ->
-    Dict;
-resolve_recursive_vars([{Key, Value0} | Rest], Dict) when is_list(Value0) ->
-    Value = render(list_to_binary(Value0), Dict),
-    resolve_recursive_vars(Rest, dict:store(Key, Value, Dict));
-resolve_recursive_vars([_Pair | Rest], Dict) ->
-    resolve_recursive_vars(Rest, Dict).
-
 %%
 %% Given a string or binary, parse it into a list of terms, ala file:consult/0
 %%
@@ -268,14 +282,6 @@ consult(Cont, Str, 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).
-
 write_file(Output, Data, Force) ->
     %% determine if the target file already exists
     FileExists = filelib:is_regular(Output),