%% @author Marc Worrell <marc@worrell.nl>
%% @copyright 2009 Marc Worrell
%% Date: 2009-08-04
%% @doc Utility functions for xml processing.
%% Copyright 2009 Marc Worrell
%%
%% 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(z_xml).
-author("Marc Worrell <marc@worrell.nl").
%% interface functions
-export([
escape/2,
escape/1
]).
-include("zotonic.hrl").
escape(#trans{} = Tr, Context) ->
escape(z_trans:lookup_fallback(Tr, Context));
escape(V, _Context) ->
escape(V).
%% @doc Escape a html text to valid a xml text so that it can be transported in XML. Translates control characters to
%% spaces, except for TAB, CR and LF.
%% @spec escape(iolist()) -> iolist()
escape(undefined) ->
<<>>;
escape(<<>>) ->
<<>>;
escape([]) ->
<<>>;
escape(L) when is_list(L) ->
escape(iolist_to_binary(L));
escape(A) when is_atom(A) ->
escape(atom_to_binary(A, utf8));
escape(B) when is_binary(B) ->
esc(B, <<>>).
esc(<<>>, Acc) ->
Acc;
esc(<<$&, T/binary>>, Acc) ->
esc(T, <<Acc/binary, "&">>);
esc(<<$<, T/binary>>, Acc) ->
esc(T, <<Acc/binary, "<">>);
esc(<<$>, T/binary>>, Acc) ->
esc(T, <<Acc/binary, ">">>);
esc(<<$", T/binary>>, Acc) ->
esc(T, <<Acc/binary, """>>);
esc(<<$', T/binary>>, Acc) ->
esc(T, <<Acc/binary, "'">>);
esc(<<C, T/binary>>, Acc) when C == 9; C == 10; C == 13 ->
esc(T, <<Acc/binary, C>>);
esc(<<C, T/binary>>, Acc) when C < 32 ->
esc(T, <<Acc/binary, 32>>);
esc(<<C/utf8, T/binary>>, Acc) ->
esc(T, <<Acc/binary, C/utf8>>).
