Have truncatewords/2 ignore tuples (e.g. timestamp) and truncatewords/3 ignore atoms (e.g. null or undefined).

src/erlydtl_filters.erl

@@ -808,6 +808,9 @@ truncatechars(Input, Max) ->
     truncatechars(Input, Max, []).
 
 %% @doc Truncates a string after a certain number of words.
+%% Do not truncate tuples, e.g. a timestamp ({{Y,M,D},{H,Mm,S}}). 
+truncatewords(Input, _) when is_tuple(Input) ->
+    Input;
 truncatewords(_Input, Max) when Max =< 0 ->
     "";
 truncatewords(Input, Max) when is_binary(Input) ->
@@ -1041,6 +1044,8 @@ truncatechars(_Input, 0, Acc) ->
 truncatechars([C|Rest], CharsLeft, Acc) ->
     truncatechars(Rest, CharsLeft - 1, [C|Acc]).
 
+truncatewords(Value, _WordsLeft, _Acc) when is_atom(Value) ->
+    Value;
 truncatewords([], _WordsLeft, Acc) ->
     lists:reverse(Acc);
 truncatewords(_Input, 0, Acc) ->