Allow extension in custom tag args.

src/erlydtl_compiler.erl

@@ -1412,14 +1412,21 @@ full_path(File, DocRoot) ->
 %%-------------------------------------------------------------------
 
 tag_ast(Name, Args, Context, TreeWalker) ->
-    {{InterpretedArgs, AstInfo1}, TreeWalker1} = lists:foldr(fun
-								 ({{identifier, _, Key}, {trans, StringLiteral}}, {{ArgsAcc, AstInfoAcc}, TreeWalkerAcc}) ->
-								    {{TransAst, TransAstInfo}, TreeWalker0} = translated_ast(StringLiteral, Context, TreeWalkerAcc),
-								    {{[erl_syntax:tuple([erl_syntax:atom(Key), TransAst])|ArgsAcc], merge_info(TransAstInfo, AstInfoAcc)}, TreeWalker0};
-								 ({{identifier, _, Key}, Value}, {{ArgsAcc, AstInfoAcc}, TreeWalkerAcc}) ->
-								    {{Ast0, AstInfo0}, TreeWalker0} = value_ast(Value, false, false, Context, TreeWalkerAcc),
-								    {{[erl_syntax:tuple([erl_syntax:atom(Key), Ast0])|ArgsAcc], merge_info(AstInfo0, AstInfoAcc)}, TreeWalker0}
-							    end, {{[], #ast_info{}}, TreeWalker}, Args),
+    {{InterpretedArgs, AstInfo1}, TreeWalker1} = 
+        lists:foldr(
+          fun ({{identifier, _, Key}, {trans, StringLiteral}}, {{ArgsAcc, AstInfoAcc}, TreeWalkerAcc}) ->
+                  {{TransAst, TransAstInfo}, TreeWalker0} = translated_ast(StringLiteral, Context, TreeWalkerAcc),
+                  {{[erl_syntax:tuple([erl_syntax:atom(Key), TransAst])|ArgsAcc], merge_info(TransAstInfo, AstInfoAcc)}, TreeWalker0};
+              ({{identifier, _, Key}, Value}, {{ArgsAcc, AstInfoAcc}, TreeWalkerAcc}) ->
+                  {{Ast0, AstInfo0}, TreeWalker0} = value_ast(Value, false, false, Context, TreeWalkerAcc),
+                  {{[erl_syntax:tuple([erl_syntax:atom(Key), Ast0])|ArgsAcc], merge_info(AstInfo0, AstInfoAcc)}, TreeWalker0};
+              ({extension, Tag}, {{ArgsAcc, AstInfoAcc}, TreeWalkerAcc}=Acc) ->
+                  case call_extension(Context, compile_ast, [Tag, Context, TreeWalkerAcc]) of
+                      undefined -> Acc;
+                      {{ExtAst, ExtInfo}, ExtTreeWalker} ->
+                          {{[ExtAst|ArgsAcc], merge_info(ExtInfo, AstInfoAcc)}, ExtTreeWalker}
+                  end
+          end, {{[], #ast_info{}}, TreeWalker}, Args),
     TagArgs = [erl_syntax:tuple([erl_syntax:atom('__render_variables'), erl_syntax:variable("_Variables")])|InterpretedArgs],
     {RenderAst, RenderInfo} = custom_tags_modules_ast(Name, TagArgs, Context),
     {{RenderAst, merge_info(AstInfo1, RenderInfo)}, TreeWalker1}.