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src/fxml.erl

%%%----------------------------------------------------------------------
%%% File : fxml.erl
%%% Author : Alexey Shchepin <alexey@process-one.net>
%%% Purpose : XML utils for parsing, matching, processing XML
%%% Created : 20 Nov 2002 by Alexey Shchepin <alexey@process-one.net>
%%%
%%%
%%% Copyright (C) 2002-2024 ProcessOne, SARL. All Rights Reserved.
%%%
%%% Licensed under the Apache License, Version 2.0 (the "License");
%%% you may not use this file except in compliance with the License.
%%% You may obtain a copy of the License at
%%%
%%% http://www.apache.org/licenses/LICENSE-2.0
%%%
%%% Unless required by applicable law or agreed to in writing, software
%%% distributed under the License is distributed on an "AS IS" BASIS,
%%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%%% See the License for the specific language governing permissions and
%%% limitations under the License.
%%%
%%%----------------------------------------------------------------------
-module(fxml).
-author('alexey@process-one.net').
-compile(no_native).
-on_load(init/0).
-export([element_to_binary/1, element_to_header/1,
crypt/1, remove_cdata/1,
remove_subtags/3, get_cdata/1, get_tag_cdata/1,
get_attr/2, get_attr_s/2, get_tag_attr/2,
get_tag_attr_s/2, get_subtag/2, get_subtags/2, get_subtag_cdata/2,
get_subtag_with_xmlns/3, get_subtags_with_xmlns/3,
append_subtags/2, get_path_s/2,
replace_tag_attr/3, replace_subtag/2, to_xmlel/1]).
-export([load_nif/0, load_nif/1]).
-include("fxml.hrl").
-export_type([xmlel/0]).
init() ->
ok = load_nif().
%% Replace element_to_binary/1 with NIF
load_nif() ->
SOPath = p1_nif_utils:get_so_path(?MODULE, [fast_xml], "fxml"),
load_nif(SOPath).
load_nif(SOPath) ->
case catch erlang:load_nif(SOPath, 0) of
ok -> ok;
Err -> error_logger:warning_msg("unable to load fxml NIF: ~p~n", [Err]),
{error, unable_to_load_nif}
end.
%%
-spec element_to_binary(El :: xmlel() | cdata()) -> binary().
element_to_binary(_El) ->
erlang:nif_error(nif_not_loaded).
-spec element_to_header(El :: xmlel()) -> binary().
element_to_header(_El) ->
erlang:nif_error(nif_not_loaded).
crypt(S) ->
<< <<(case C of
$& -> <<"&amp;">>;
$< -> <<"&lt;">>;
$> -> <<"&gt;">>;
$" -> <<"&quot;">>;
$' -> <<"&apos;">>;
_ -> <<C>>
end)/binary>>
|| <<C>> <= S >>.
%%
-spec remove_cdata_p(El :: xmlel() | cdata()) -> boolean().
remove_cdata_p(#xmlel{}) -> true;
remove_cdata_p(_) -> false.
%%
-spec remove_cdata(L :: [xmlel() | cdata()]) -> [xmlel()].
remove_cdata(L) -> [E || E <- L, remove_cdata_p(E)].
%% This function is intended to remove subtags based on a name and an
%% attribute, usually an xmlns attribute for a specific XMPP
%% extension.
-spec remove_subtags(Xmlel :: xmlel(), Name :: binary(),
Attr :: attr()) -> Xmlel :: xmlel().
remove_subtags(#xmlel{name = TagName, attrs = TagAttrs, children = Els},
Name, Attr) ->
#xmlel{name = TagName, attrs = TagAttrs,
children = remove_subtags1(Els, [], Name, Attr)}.
%%
-spec remove_subtags1(Els :: [xmlel() | cdata()], NewEls :: [xmlel()],
Name :: binary(), Attr :: attr()) ->
NewEls :: [xmlel()].
remove_subtags1([], NewEls, _Name, _Attr) ->
lists:reverse(NewEls);
remove_subtags1([El | Els], NewEls, Name,
{AttrName, AttrValue} = Attr) ->
case El of
#xmlel{name = Name, attrs = Attrs} ->
case get_attr(AttrName, Attrs) of
false ->
remove_subtags1(Els, [El | NewEls], Name, Attr);
{value, AttrValue} ->
remove_subtags1(Els, NewEls, Name, Attr);
_ -> remove_subtags1(Els, [El | NewEls], Name, Attr)
end;
_ -> remove_subtags1(Els, [El | NewEls], Name, Attr)
end.
-spec get_cdata(L :: [xmlel() | cdata()]) -> binary().
get_cdata(L) ->
(iolist_to_binary(get_cdata(L, <<"">>))).
-spec get_cdata(L :: [xmlel() | cdata()],
S :: binary() | iolist()) ->
binary() | iolist().
get_cdata([{xmlcdata, CData} | L], S) ->
get_cdata(L, [S, CData]);
get_cdata([_ | L], S) -> get_cdata(L, S);
get_cdata([], S) -> S.
-spec get_tag_cdata(Xmlel :: xmlel()) -> binary().
get_tag_cdata(#xmlel{children = Els}) -> get_cdata(Els).
%%
-spec get_attr(AttrName :: binary(), Attrs :: [attr()]) ->
{value, binary()} | false.
get_attr(AttrName, Attrs) ->
case lists:keysearch(AttrName, 1, Attrs) of
{value, {_, Val}} -> {value, Val};
_ -> false
end.
%%
-spec get_attr_s(AttrName :: binary(), Attrs :: [attr()]) ->
Val :: binary().
get_attr_s(AttrName, Attrs) ->
case lists:keysearch(AttrName, 1, Attrs) of
{value, {_, Val}} -> Val;
_ -> <<"">>
end.
%%
-spec get_tag_attr(AttrName :: binary(), Xmlel :: xmlel()) ->
{value, binary()} | false.
get_tag_attr(AttrName, #xmlel{attrs = Attrs}) ->
get_attr(AttrName, Attrs).
%%
-spec get_tag_attr_s(AttrName :: binary(), Xmlel :: xmlel()) -> binary().
get_tag_attr_s(AttrName, #xmlel{attrs = Attrs}) ->
get_attr_s(AttrName, Attrs).
%%
-spec get_subtag(Xmlel :: xmlel(), Name :: binary()) -> xmlel() | false.
get_subtag(#xmlel{children = Els}, Name) ->
get_subtag1(Els, Name).
%%
-spec get_subtag1(Els :: [xmlel() | cdata()], Name :: binary()) ->
xmlel() | false.
get_subtag1( [El | Els], Name) ->
case El of
#xmlel{name = Name} -> El;
_ -> get_subtag1(Els, Name)
end;
get_subtag1([], _) -> false.
-spec get_subtags(Xmlel :: xmlel(), Name :: binary()) -> [xmlel()].
get_subtags(#xmlel{children = Els}, Name) ->
get_subtags1(Els, Name, []).
get_subtags1([], _Name, Acc) ->
lists:reverse(Acc);
get_subtags1([El | Els], Name, Acc) ->
case El of
#xmlel{name = Name} -> get_subtags1(Els, Name, [El|Acc]);
_ -> get_subtags1(Els, Name, Acc)
end.
%%
-spec get_subtag_with_xmlns(Xmlel :: xmlel(), Name :: binary(),
XMLNS :: binary()) -> xmlel() | false.
get_subtag_with_xmlns(#xmlel{children = Els}, Name, XMLNS) ->
get_subtag_with_xmlns1(Els, Name, XMLNS).
%%
-spec get_subtag_with_xmlns1(Els :: [xmlel() | cdata()], Name :: binary(),
XMLNS :: binary()) -> xmlel() | false.
get_subtag_with_xmlns1([El | Els], Name, XMLNS) ->
case El of
#xmlel{name = Name, attrs = Attrs} ->
case get_attr(<<"xmlns">>, Attrs) of
{value, XMLNS} ->
El;
_ ->
get_subtag_with_xmlns1(Els, Name, XMLNS)
end;
_ ->
get_subtag_with_xmlns1(Els, Name, XMLNS)
end;
get_subtag_with_xmlns1([], _, _) ->
false.
-spec get_subtags_with_xmlns(Xmlel :: xmlel(), Name :: binary(),
XMLNS :: binary()) -> [xmlel()].
get_subtags_with_xmlns(#xmlel{children = Els}, Name, XMLNS) ->
get_subtags_with_xmlns1(Els, Name, XMLNS, []).
get_subtags_with_xmlns1([], _Name, _XMLNS, Acc) ->
lists:reverse(Acc);
get_subtags_with_xmlns1([El | Els], Name, XMLNS, Acc) ->
case El of
#xmlel{name = Name, attrs = Attrs} ->
case get_attr(<<"xmlns">>, Attrs) of
{value, XMLNS} ->
get_subtags_with_xmlns1(Els, Name, XMLNS, [El|Acc]);
_ ->
get_subtags_with_xmlns1(Els, Name, XMLNS, Acc)
end;
_ ->
get_subtags_with_xmlns1(Els, Name, XMLNS, Acc)
end.
%%
-spec get_subtag_cdata(Tag :: xmlel(), Name :: binary()) -> binary().
get_subtag_cdata(Tag, Name) ->
case get_subtag(Tag, Name) of
false -> <<"">>;
Subtag -> get_tag_cdata(Subtag)
end.
%%
-spec append_subtags(Xmlel :: xmlel(), SubTags2 :: [xmlel() | cdata()]) ->
Xmlel :: xmlel().
append_subtags(#xmlel{name = Name, attrs = Attrs, children = SubTags1}, SubTags2) ->
#xmlel{name = Name, attrs = Attrs, children = SubTags1 ++ SubTags2}.
%%
-spec get_path_s(El :: xmlel(), Path :: [{elem, Name::binary()} |
{attr, Name::binary()} |cdata]) ->
xmlel() | binary().
get_path_s(El, []) -> El;
get_path_s(El, [{elem, Name} | Path]) ->
case get_subtag(El, Name) of
false -> <<"">>;
SubEl -> get_path_s(SubEl, Path)
end;
get_path_s(El, [{attr, Name}]) ->
get_tag_attr_s(Name, El);
get_path_s(El, [cdata]) -> get_tag_cdata(El).
%%
-spec replace_tag_attr(Name :: binary(), Value :: binary(),
Xmlel :: xmlel()) ->
Xmlel :: #xmlel{ name :: binary(),
attrs :: [attr(),...],
children :: [xmlel() | cdata()] }.
replace_tag_attr(Name, Value, Xmlel) ->
Xmlel#xmlel{
attrs = [{Name, Value} | lists:keydelete(Name, 1, Xmlel#xmlel.attrs)]
}.
-spec replace_subtag(Tag :: xmlel(), Xmlel :: xmlel()) ->
Xmlel :: #xmlel{ name :: binary(),
attrs :: [attr(),...],
children :: [xmlel() | cdata()] }.
replace_subtag(#xmlel{name = Name} = Tag, Xmlel) ->
Xmlel#xmlel{
children = [Tag | lists:keydelete(Name, #xmlel.name, Xmlel#xmlel.children)]
}.
to_xmlel({_, Name, Attrs, Els}) ->
#xmlel{name = iolist_to_binary(Name),
attrs = [{iolist_to_binary(K), iolist_to_binary(V)}
|| {K, V} <- Attrs],
children = [to_xmlel(El) || El <- Els]};
to_xmlel({xmlcdata, CData}) ->
{xmlcdata, iolist_to_binary(CData)}.