From 63d5ceb61d68af7f1847e3442a1d3f56b6808672 Mon Sep 17 00:00:00 2001 From: David Reid Date: Thu, 11 Nov 2010 09:41:13 -0800 Subject: [PATCH] Support single level of nested template variables Add support for defining template variables of the following form: {variables, [{appid, "mochiwebapp"}, {author, "Mochi Media "}, {year, "2010"}, {version, "0.1"}, {port, 8080}, {dest, "{{appid}}"}]}. Where dest may be overridden on the commandline but will default to being the appid. Mochiweb uses this so that we can create new projects from the template in a configurable directory. So $ rebar create template=mochiwebapp dest=foo appid=bar I thought about special casing dest but figured it might be generally useful to be able to nest template vars. However this patch only does one level of resolution. So if {variables, [{foo, "{{bar}}"}, {bar, "{{foo}}"}]}. then bar will end up being the literal string {{bar}} and foo the literal string {{foo}}. --- src/rebar_templater.erl | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/src/rebar_templater.erl b/src/rebar_templater.erl index 4aa5ed6..e251f40 100644 --- a/src/rebar_templater.erl +++ b/src/rebar_templater.erl @@ -104,8 +104,14 @@ create(_Config, _) -> %% 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)]), + Context1 = update_vars(dict:fetch_keys(Context0), Context0), + ?DEBUG("Template ~p context: ~p\n", [template_id(), dict:to_list(Context1)]), + + %% Handle variables that possibly include other variables in their + %% definition + Context = resolve_recursive_vars(dict:to_list(Context1), Context1), + + ?DEBUG("Resolved Template ~p context: ~p\n", [template_id(), dict:to_list(Context1)]), %% Now, use our context to process the template definition -- this permits us to %% use variables within the definition for filenames. @@ -205,6 +211,19 @@ 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 %% @@ -319,4 +338,3 @@ execute_template([{variables, _} | Rest], TemplateType, TemplateName, Context, F 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). -