%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2003-2009. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
%%% Description : Simple event-based processor (front-end to xmerl_scan)
%% @doc Simple event-based front-ends to xmerl_scan for processing
%% of XML documents in streams and for parsing in SAX style.
%% Each contain more elaborate settings of xmerl_scan that makes usage of
%% the customization functions.
%%
-module(xmerl_eventp).
-vsn('0.19').
-date('03-09-17').
-export([stream/2,stream_sax/4, file_sax/4, string_sax/4]).
% -export([cont/3, rules_read/3,rules_write/4,fetch/2,close/1]).
-include("xmerl.hrl").
-include("xmerl_internal.hrl").
-include_lib("kernel/include/file.hrl").
%% @spec stream(Fname::string(), Options::option_list()) -> xmlElement()
%%
%% @doc Parse file containing an XML document as a stream, DOM style.
%% Wrapper for a call to the XML parser <code>xmerl_scan</code> with a
%% <code>continuation_fun</code> for handling streams of XML data.
%% Note that the <code>continuation_fun</code>, <code>acc_fun</code>,
%% <code>fetch_fun</code>, <code>rules</code> and <code>close_fun</code>
%% options cannot be user defined using this parser.
stream(Fname, Options) ->
AccF = fun(X, Acc, S) -> acc(X,Acc,S) end,
case file:open(Fname, [read, raw, binary]) of
{ok, Fd} ->
B0 = list_to_binary([]),
ContS = [{B0, Fname, Fd}],
Opts=scanner_options(Options,
[{continuation_fun, fun cont/3, ContS},
{acc_fun, AccF},
{fetch_fun, fun fetch/2},
{rules,fun rules_read/3,fun rules_write/4,""},
{close_fun, fun close/1}]),
xmerl_scan:string([], Opts);
Error ->
Error
end.
%% @spec stream_sax(Fname,CallBackModule,UserState,Options) -> xmlElement()
%% Fname = string()
%% CallBackModule = atom()
%% Options = option_list()
%%
%% @doc Parse file containing an XML document as a stream, SAX style.
%% Wrapper for a call to the XML parser <code>xmerl_scan</code> with a
%% <code>continuation_fun</code> for handling streams of XML data.
%% Note that the <code>continuation_fun</code>, <code>acc_fun</code>,
%% <code>fetch_fun</code>, <code>rules</code>, <code>hook_fun</code>,
%% <code>close_fun</code> and <code>user_state</code> options cannot be user
%% defined using this parser.
stream_sax(Fname, CallBack, UserState,Options) ->
US={xmerl:callbacks(CallBack), UserState},
AccF = fun(X, Acc, S) -> acc(X,Acc,S) end,
HookF=
fun(ParsedEntity, S) ->
{CBs,Arg}=xmerl_scan:user_state(S),
% io:format("stream_sax Arg=~p~n",[Arg]),
case ParsedEntity of
#xmlComment{} -> % Toss away comments...
{[],S};
_ -> % Use callback module for the rest
% io:format("stream_sax ParsedEntity=~p~n",[ParsedEntity]),
case xmerl:export_element(ParsedEntity,CBs,Arg) of
{error,Reason} ->
throw({error,Reason});
Resp ->
% io:format("stream_sax Resp=~p~n",[Resp]),
{Resp,xmerl_scan:user_state({CBs,Resp},S)}
end
end
end,
case file:open(Fname, [read, raw, binary]) of
{ok, Fd} ->
B0 = list_to_binary([]),
ContS = [{B0, Fname, Fd}],
Opts=scanner_options(Options,
[{acc_fun, AccF},
{close_fun, fun close/1},
{continuation_fun, fun cont/3, ContS},
{fetch_fun, fun fetch/2},
{hook_fun,HookF},
{rules,fun rules_read/3,fun rules_write/4,""},
{user_state,US}]),
xmerl_scan:string([], Opts);
Error ->
Error
end.
%% @spec file_sax(Fname::string(), CallBackModule::atom(), UserState,
%% Options::option_list()) -> NewUserState
%%
%% @doc Parse file containing an XML document, SAX style.
%% Wrapper for a call to the XML parser <code>xmerl_scan</code> with a
%% <code>hook_fun</code> for using xmerl export functionality directly after
%% an entity is parsed.
file_sax(Fname,CallBack, UserState, Options) ->
US={xmerl:callbacks(CallBack), UserState},
AccF=fun(X,Acc,S) -> {[X|Acc], S} end,
HookF=
fun(ParsedEntity, S) ->
{CBs,Arg}=xmerl_scan:user_state(S),
case ParsedEntity of
#xmlComment{} -> % Toss away comments...
{[],S};
_ -> % Use callback module for the rest
case xmerl:export_element(ParsedEntity,CBs,Arg) of
{error,Reason} ->
throw({error,Reason});
Resp ->
{Resp,xmerl_scan:user_state({CBs,Resp},S)}
end
end
end,
Opts=scanner_options(Options,[{acc_fun, AccF},
{hook_fun,HookF},
{user_state,US}]),
xmerl_scan:file(Fname,Opts).
%% @spec string_sax(String::list(), CallBackModule::atom(), UserState,
%% Options::option_list()) ->
%% xmlElement()
%%
%% @doc Parse file containing an XML document, SAX style.
%% Wrapper for a call to the XML parser <code>xmerl_scan</code> with a
%% <code>hook_fun</code> for using xmerl export functionality directly after
%% an entity is parsed.
string_sax(String,CallBack, UserState, Options) ->
US={xmerl:callbacks(CallBack), UserState},
AccF=fun(X,Acc,S) -> {[X|Acc], S} end,
HookF=
fun(ParsedEntity, S) ->
{CBs,Arg}=xmerl_scan:user_state(S),
case ParsedEntity of
#xmlComment{} -> % Toss away comments...
{[],S};
_ -> % Use callback module for the rest
case xmerl:export_element(ParsedEntity,CBs,Arg) of
{error,Reason} ->
throw({error,Reason});
Resp ->
{Resp,xmerl_scan:user_state({CBs,Resp},S)}
end
end
end,
Opts=scanner_options(Options,[{acc_fun, AccF},
{hook_fun,HookF},
{user_state,US}]),
xmerl_scan:string(String,Opts).
%%% ----------------------------------------------------------------------------
%%% Streaming support functions
%%% Continuation callback function for xmerl_scan
cont(F, Exception, S) ->
case xmerl_scan:cont_state(S) of
[{_Fname, eof}|_] ->
Exception(S);
[{Sofar, Fname, Fd}|T] ->
cont2(F, Exception, Sofar, Fd, Fname, T, S)
end.
cont2(F, Exception, Sofar, Fd, Fname, T, S) ->
case catch read_chunk(Fd, Fname, Sofar) of
{ok, Bin} ->
find_good_split(list_to_binary([Sofar,Bin]),
F,Exception,Fd,Fname,T,S);
eof ->
file:close(Fd),
NewS = xmerl_scan:cont_state([{Fname, eof}|T], S),
F(binary_to_list(Sofar), NewS);
Error ->
exit(Error)
end.
read_chunk(Fd, _Fname, _Sofar) ->
file:read(Fd, 8192).
-ifndef(no_bitsyntax).
find_good_split(Bin, F, Exception, Fd, Fname, T, S) ->
find_good_split(size(Bin)-1, Bin, F, Exception, Fd, Fname, T, S).
find_good_split(0, B, F, Exception, Fd, Fname, T, S) ->
cont2(F, Exception, B, Fd, Fname, T, S);
find_good_split(Size, B, F, Exception, Fd, Fname, T, S) ->
case B of
<<_Bytes:Size/binary, H/integer, Tail/binary>> when ?whitespace(H) ->
{SubB,_} = split_binary(B, Size+1),
NewS = xmerl_scan:cont_state([{Tail, Fname, Fd}|T], S),
F(binary_to_list(SubB), NewS);
_ ->
find_good_split(Size-1, B, F, Exception, Fd, Fname, T, S)
end.
-else.
find_good_split(Bin, F, Exception, Fd, Fname, T, S) ->
find_good_split(size(Bin), Bin, F, Exception, Fd, Fname, T, S).
find_good_split(0, B, F, Exception, Fd, Fname, T, S) ->
cont2(F, Exception, B, Fd, Fname, T, S);
find_good_split(Size, B, F, Exception, Fd, Fname, T, S) ->
case binary_to_list(B, Size, Size) of
[H] when ?whitespace(H) ->
{SubB,Tail} = split_binary(B, Size),
NewS = xmerl_scan:cont_state([{Tail, Fname, Fd}|T], S),
F(binary_to_list(SubB), NewS);
_ ->
find_good_split(Size-1, B, F, Exception, Fd, Fname, T, S)
end.
-endif.
%%% Accumulator callback function for xmerl_scan
acc(X = #xmlText{value = Text}, Acc, S) ->
case detect_nul_text(Text) of
ok->
{[X#xmlText{value = lists:flatten(Text)}|Acc], S};
nok->
{Acc,S}
end;
acc(X, Acc, S) ->
{[X|Acc], S}.
%%% don't acc xmlText when text contains only " " , "\n" and "\t".
detect_nul_text([H|T]) when H==10; H==32; H==9->
detect_nul_text(T);
detect_nul_text([]) ->
nok;
detect_nul_text(_)->
ok.
%%% Fetch callback function for xmerl_scan
fetch({system, URI}, S) ->
fetch_URI(URI, S);
fetch({public, _PublicID, URI}, S) ->
fetch_URI(URI, S).
fetch_URI(URI, S) ->
%% assume URI is a filename
Split = filename:split(URI),
Filename = lists:last(Split),
Fullname =
case Split of
["/", _|_] ->
%% absolute path name
URI;
["file:",Name]->
%% file:/dtd_name
filename:join(S#xmerl_scanner.xmlbase, Name);
_ ->
filename:join(S#xmerl_scanner.xmlbase, URI)
end,
File = path_locate(S#xmerl_scanner.fetch_path, Filename, Fullname),
?dbg("fetch(~p) -> {file, ~p}.~n", [URI, File]),
case file:open(File, [read, raw, binary]) of
{ok, Fd} ->
ContS=xmerl_scan:cont_state(S),
NewS=xmerl_scan:cont_state([{list_to_binary([]),File,Fd}|ContS],S),
{ok, {string, []}, NewS};
_Error ->
?dbg("ERROR fetch(~p) -> ~p~n", [URI, _Error]),
{ok, not_fetched, S}
end.
path_locate([Dir|Dirs], FN, FullName) ->
F = filename:join(Dir, FN),
case file:read_file_info(F) of
{ok, #file_info{type = regular}} ->
F;
_ ->
path_locate(Dirs, FN, FullName)
end;
path_locate([], _FN, FullName) ->
FullName.
%%% Close callback function for xmerl_scan
close(S) ->
ContS = xmerl_scan:cont_state(S),
case ContS of
[{_Fname, eof}|T] ->
xmerl_scan:cont_state(T, S);
[{_Sofar, _Fname, Fd}|T] ->
file:close(Fd),
xmerl_scan:cont_state(T, S)
end.
%%% Rules callback functions for xmerl_scan
rules_write(Context, Name, Value, #xmerl_scanner{rules = undefined}=S) ->
Tab = ets:new(rules, [set, public]),
rules_write(Context, Name, Value, S#xmerl_scanner{rules = Tab});
rules_write(Context, Name, Value, #xmerl_scanner{rules = T} = S) ->
ets:insert(T, {{Context, Name}, Value}),
S.
rules_read(_Context, _Name, #xmerl_scanner{rules = undefined}) ->
undefined;
rules_read(Context, Name, #xmerl_scanner{rules = T}) ->
case ets:lookup(T, {Context, Name}) of
[] ->
undefined;
[{_K, V}] ->
V
end.
%%% ----------------------------------------------------------------------------
%%% Generic helper functions
scanner_options([H|T], Opts) ->
case catch keyreplace(H, 1, Opts) of
false ->
scanner_options(T, [H|Opts]);
NewOpts ->
scanner_options(T, NewOpts)
end;
scanner_options([], Opts) ->
Opts.
keyreplace(X, Pos, [H|T]) when element(Pos, X) == element(Pos, H) ->
[X|T];
keyreplace(X, Pos, [H|T]) ->
[H|keyreplace(X, Pos, T)];
keyreplace(_, _Pos, []) ->
throw(false).
