erlydtl/src/erlydtl_runtime.erl

-module(erlydtl_runtime).

-compile(export_all).

-type translate_fun() :: fun((string() | binary()) -> string() | binary() | undefined).

-define(IFCHANGED_CONTEXT_VARIABLE, erlydtl_ifchanged_context).

find_value(Key, Data, Options) when is_atom(Key), is_tuple(Data) ->
    Rec = element(1, Data),
    Info = proplists:get_value(record_info, Options),
    case proplists:get_value(Rec, Info) of
        Fields when is_list(Fields), length(Fields) == size(Data) - 1 ->
            case proplists:get_value(Key, Fields) of
                Idx when is_integer(Idx) -> element(Idx, Data);
                _ -> undefined
            end;
        _ -> find_value(Key, Data)
    end;
find_value(Key, Data, Options) when is_integer(Key), is_list(Data) ->
    find_value(adjust_index(Key, 1, lists_0_based, Options), Data);
find_value(Key, Data, _Options) ->
    find_value(Key, Data).

adjust_index(Key, Off, Opt, Options) when is_list(Options) ->
    case proplists:get_value(Opt, Options) of
        defer ->
            adjust_index(
              Key, Off, Opt,
              proplists:get_value(render_options, Options));
        true ->
            Key + Off;
        _ ->
            Key
    end;
adjust_index(Key, _Off, _Opt, _Options) -> Key.

find_value(_, undefined) ->
    undefined;
find_value(Key, Fun) when is_function(Fun, 1) ->
    Fun(Key);
find_value(Key, L) when is_atom(Key), is_list(L) ->
    case lists:keyfind(Key, 1, L) of
        false           -> find_value(atom_to_list(Key), L);
        {Key, Value}    -> Value
    end;
find_value(Key, L) when is_list(Key), is_list(L) ->
    case lists:keyfind(Key, 1, L) of
        false           -> find_value(list_to_binary(Key), L);
        {Key, Value}    -> Value
    end;
find_value(Key, L) when is_binary(Key), is_list(L) ->
    case lists:keyfind(Key, 1, L) of
        false           -> undefined;
        {Key, Value}    -> Value
    end;
find_value(Key, L) when is_integer(Key), is_list(L) ->
    if Key =< length(L) -> lists:nth(Key, L);
       true -> undefined
    end;
find_value(Key, {GBSize, GBData}) when is_integer(GBSize) ->
    case gb_trees:lookup(Key, {GBSize, GBData}) of
        {value, Val} ->
            Val;
        _ ->
            undefined
    end;
find_value(Key, Tuple) when is_tuple(Tuple) ->
    case element(1, Tuple) of
        dict ->
            case dict:find(Key, Tuple) of
                {ok, Val} ->
                    Val;
                _ ->
                    undefined
            end;
        _ when is_integer(Key) ->
            if Key < size(Tuple) -> element(Key, Tuple);
               true -> undefined
            end;
        Module ->
            case lists:member({Key, 1}, Module:module_info(exports)) of
                true ->
                    case Tuple:Key() of
                        Val when is_tuple(Val) ->
                            case element(1, Val) of
                                'Elixir.Ecto.Associations.BelongsTo' -> Val:get();
                                'Elixir.Ecto.Associations.HasOne' -> Val:get();
                                _ -> Val
                            end;
                        Val -> Val
                    end;
                _ ->
                    undefined
            end
    end.

fetch_value(Key, Data, Options) ->
    case find_value(Key, Data, Options) of
        undefined -> [];
        Val -> Val
    end.

find_deep_value([Key|Rest],Item) ->
    case find_value(Key,Item) of
        undefined -> undefined;
        NewItem -> find_deep_value(Rest,NewItem)
    end;
find_deep_value([],Item) -> Item.

regroup(List, Attribute) ->
    regroup(List, Attribute, []).

regroup([], _, []) ->
    [];
regroup([], _, [[{grouper, LastGrouper}, {list, LastList}]|Acc]) ->
    lists:reverse([[{grouper, LastGrouper}, {list, lists:reverse(LastList)}]|Acc]);
regroup([Item|Rest], Attribute, []) ->
    regroup(Rest, Attribute, [[{grouper, find_deep_value(Attribute, Item)}, {list, [Item]}]]);
regroup([Item|Rest], Attribute, [[{grouper, PrevGrouper}, {list, PrevList}]|Acc]) ->
    case find_deep_value(Attribute, Item) of
        Value when Value =:= PrevGrouper ->
            regroup(Rest, Attribute, [[{grouper, PrevGrouper}, {list, [Item|PrevList]}]|Acc]);
        Value ->
            regroup(Rest, Attribute, [[{grouper, Value}, {list, [Item]}], [{grouper, PrevGrouper}, {list, lists:reverse(PrevList)}]|Acc])
    end.

-spec translate(Str, none | translate_fun()) -> Str when
      Str :: string() | binary().
translate(String, none) -> String;
translate(String, TranslationFun)
  when is_function(TranslationFun) ->
    case TranslationFun(String) of
        undefined -> String;
        <<"">> -> String;
        "" -> String;
        Str -> Str
    end.

%% @doc Translate and interpolate 'blocktrans' content.
%% Pre-requisites:
%%  * `Variables' should be sorted
%%  * Each interpolation variable should exist
%%    (String="{{a}}", Variables=[{"b", "b-val"}] will fall)
%%  * Orddict keys should be string(), not binary()
-spec translate_block(string() | binary(), translate_fun(), orddict:orddict()) -> iodata().
translate_block(String, TranslationFun, Variables) ->
    TransString = case TranslationFun(String) of
                      No when (undefined == No)
                              orelse (<<"">> == No)
                              orelse ("" == No) -> String;
                      Str -> Str
                  end,
    try interpolate_variables(TransString, Variables)
    catch _:_ ->
            %% Fallback to default language in case of errors (like Djando does)
            interpolate_variables(String, Variables)
    end.

interpolate_variables(Tpl, []) ->
    Tpl;
interpolate_variables(Tpl, Variables) ->
    BTpl = iolist_to_binary(Tpl),
    interpolate_variables1(BTpl, Variables).

interpolate_variables1(Tpl, Vars) ->
    %% pre-compile binary patterns?
    case binary:split(Tpl, <<"{{">>) of
        [NotFound] ->
            [NotFound];
        [Pre, Post] ->
            case binary:split(Post, <<"}}">>) of
                [_] -> throw({no_close_var, Post});
                [Var, Post1] ->
                    Var1 = string:strip(binary_to_list(Var)),
                    Value = orddict:fetch(Var1, Vars),
                    [Pre, Value | interpolate_variables1(Post1, Vars)]
            end
    end.


are_equal(Arg1, Arg2) when Arg1 =:= Arg2 ->
    true;
are_equal(Arg1, Arg2) when is_binary(Arg1) ->
    are_equal(binary_to_list(Arg1), Arg2);
are_equal(Arg1, Arg2) when is_binary(Arg2) ->
    are_equal(Arg1, binary_to_list(Arg2));
are_equal(Arg1, Arg2) when is_integer(Arg1) ->
    are_equal(integer_to_list(Arg1), Arg2);
are_equal(Arg1, Arg2) when is_integer(Arg2) ->
    are_equal(Arg1, integer_to_list(Arg2));
are_equal(Arg1, Arg2) when is_atom(Arg1), is_list(Arg2) ->
    are_equal(atom_to_list(Arg1), Arg2);
are_equal(Arg1, Arg2) when is_list(Arg1), is_atom(Arg2) ->
    are_equal(Arg1, atom_to_list(Arg2));
are_equal(_, _) ->
    false.

is_false("") -> true;
is_false(false) -> true;
is_false(undefined) -> true;
is_false(0) -> true;
is_false("0") -> true;
is_false(<<"0">>) -> true;
is_false(<<>>) -> true;
is_false(_) -> false.

is_true(V) -> not is_false(V).

'in'(Sublist, [Sublist|_]) ->
    true;
'in'(Sublist, List) when is_atom(List) ->
    'in'(Sublist, atom_to_list(List));
'in'(Sublist, List) when is_binary(Sublist) ->
    'in'(binary_to_list(Sublist), List);
'in'(Sublist, List) when is_binary(List) ->
    'in'(Sublist, binary_to_list(List));
'in'(Sublist, [C|Rest]) when is_list(Sublist) andalso is_binary(C) ->
    'in'(Sublist, [binary_to_list(C)|Rest]);
'in'(Sublist, [C|Rest]) when is_list(Sublist) andalso is_list(C) ->
    'in'(Sublist, Rest);
'in'(Sublist, List) when is_list(Sublist) andalso is_list(List) ->
    string:str(List, Sublist) > 0;
'in'(Element, List) when is_list(List) ->
    lists:member(Element, List);
'in'(_, _) ->
    false.

'not'(Value) ->
    not is_true(Value).

'or'(Value1, Value2) ->
    is_true(Value1) or is_true(Value2).

'and'(Value1, Value2) ->
    is_true(Value1) and is_true(Value2).

'eq'(Value1, Value2) ->
    are_equal(Value1, Value2).

'ne'(Value1, Value2) ->
    not are_equal(Value1, Value2).

'le'(Value1, Value2) ->
    not 'gt'(Value1, Value2).

'ge'(Value1, Value2) ->
    not 'lt'(Value1, Value2).

'gt'(Value1, Value2) when is_list(Value1) ->
    'gt'(list_to_integer(Value1), Value2);
'gt'(Value1, Value2) when is_list(Value2) ->
    'gt'(Value1, list_to_integer(Value2));
'gt'(Value1, Value2) when Value1 > Value2 ->
    true;
'gt'(_, _) ->
    false.

'lt'(Value1, Value2) when is_list(Value1) ->
    'lt'(list_to_integer(Value1), Value2);
'lt'(Value1, Value2) when is_list(Value2) ->
    'lt'(Value1, list_to_integer(Value2));
'lt'(Value1, Value2) when Value1 < Value2 ->
    true;
'lt'(_, _) ->
    false.

stringify_final(In, BinaryStrings) ->
    stringify_final(In, [], BinaryStrings).

stringify_final([], Out, _) ->
    lists:reverse(Out);
stringify_final([El | Rest], Out, false = BinaryStrings) when is_atom(El) ->
    stringify_final(Rest, [atom_to_list(El) | Out], BinaryStrings);
stringify_final([El | Rest], Out, true = BinaryStrings) when is_atom(El) ->
    stringify_final(Rest, [atom_to_binary(El, latin1) | Out], BinaryStrings);
stringify_final([El | Rest], Out, BinaryStrings) when is_list(El) ->
    stringify_final(Rest, [stringify_final(El, BinaryStrings) | Out], BinaryStrings);
stringify_final([El | Rest], Out, false = BinaryStrings) when is_tuple(El) ->
    stringify_final(Rest, [io_lib:print(El) | Out], BinaryStrings);
stringify_final([El | Rest], Out, true = BinaryStrings) when is_tuple(El) ->
    stringify_final(Rest, [list_to_binary(io_lib:print(El)) | Out], BinaryStrings);
stringify_final([El | Rest], Out, BinaryStrings) ->
    stringify_final(Rest, [El | Out], BinaryStrings).

to_list(Value, true) ->
    lists:reverse(to_list(Value, false));
to_list(Value, false) when is_list(Value) ->
    Value;
to_list(Value, false) when is_tuple(Value) ->
    case element(1, Value) of
        'Elixir.Ecto.Associations.HasMany' ->
            Value:to_list();
        _ ->
            tuple_to_list(Value)
    end.

init_counter_stats(List) ->
    init_counter_stats(List, undefined).

init_counter_stats(List, Parent) when is_list(List) ->
    ListLen = length(List),
    [{counter, 1},
     {counter0, 0},
     {revcounter, ListLen},
     {revcounter0, ListLen - 1},
     {first, true},
     {last, ListLen =:= 1},
     {parentloop, Parent}].

increment_counter_stats([{counter, Counter}, {counter0, Counter0}, {revcounter, RevCounter},
                         {revcounter0, RevCounter0}, {first, _}, {last, _}, {parentloop, Parent}]) ->
    [{counter, Counter + 1},
     {counter0, Counter0 + 1},
     {revcounter, RevCounter - 1},
     {revcounter0, RevCounter0 - 1},
     {first, false}, {last, RevCounter0 =:= 1},
     {parentloop, Parent}].

forloop(_Fun, [], _Parent) -> empty;
forloop(Fun, Values, Parent) ->
    push_ifchanged_context(),
    Result = lists:mapfoldl(Fun, init_counter_stats(Values, Parent), Values),
    pop_ifchanged_context(),
    Result.

push_ifchanged_context() ->
    IfChangedContextStack = case get(?IFCHANGED_CONTEXT_VARIABLE) of
                                undefined -> [];
                                Stack -> Stack
                            end,
    put(?IFCHANGED_CONTEXT_VARIABLE, [[]|IfChangedContextStack]).

pop_ifchanged_context() ->
    [_|Rest] = get(?IFCHANGED_CONTEXT_VARIABLE),
    put(?IFCHANGED_CONTEXT_VARIABLE, Rest).

ifchanged(Expressions) ->
    [IfChangedContext|Rest] = get(?IFCHANGED_CONTEXT_VARIABLE),
    {Result, NewContext} = lists:foldl(fun (Expr, {ProvResult, Context}) when ProvResult == true ->
                                               {_, NContext} = ifchanged2(Expr, Context),
                                               {true, NContext};
                                           (Expr, {_ProvResult, Context}) ->
                                               ifchanged2(Expr, Context)
                                       end, {false, IfChangedContext}, Expressions),
    put(?IFCHANGED_CONTEXT_VARIABLE, [NewContext|Rest]),
    Result.

ifchanged2({Key, Value}, IfChangedContext) ->
    PreviousValue = proplists:get_value(Key, IfChangedContext),
    if
        PreviousValue =:= Value ->
            {false, IfChangedContext};
        true ->
            NewContext = [{Key, Value}|proplists:delete(Key, IfChangedContext)],
            {true, NewContext}
    end.

cycle(NamesTuple, Counters) when is_tuple(NamesTuple) ->
    element(find_value(counter0, Counters) rem size(NamesTuple) + 1, NamesTuple).

widthratio(Numerator, Denominator, Scale) ->
    round(Numerator / Denominator * Scale).

spaceless(Contents) ->
    Contents1 = lists:flatten(Contents),
    Contents2 = re:replace(Contents1, "^\\s+<", "<", [{return,list}]),
    Contents3 = re:replace(Contents2, ">\\s+$", ">", [{return,list}]),
    Contents4 = re:replace(Contents3, ">\\s+<", "><", [global, {return,list}]),
    Contents4.

read_file(Module, Function, DocRoot, FileName) ->
    AbsName = case filename:absname(FileName) of
                  FileName -> FileName;
                  _ -> filename:join([DocRoot, FileName])
              end,
    case Module:Function(AbsName) of
        {ok, Data} -> Data;
        {error, Reason} ->
            throw({read_file, AbsName, Reason})
    end.