ProcessOne Discussion Forums

what type of parameter exmpp_xml:set_attributes/2 accept? atom or binary?

2011-07-01T09:35:56+01:00

Hi,
The specification in the devdoc of exmpp defines exmpp_xml:set_attributes/2 as below:
set_attributes(XML_Element, Rest::Attrs_Spec) -> New_XML_Element
XML_Element = xmlel() | xmlel_old()
Attrs_Spec = [{Name, Value} | {NS, Name, Value} | xmlattr_old() | xmlattr()]
NS = atom() | string()
Name = binary()
Value = binary() | string() | atom() | integer()
New_XML_Element = xmlel() | xmlel_old()

we can see that Name should be binary(), but the code in exmpp_xmpp.hrl use atoms:

-define(IQ(Type, To, Id), (
  exmpp_xml:set_attributes(
    #xmlel{ns = ?NS_JABBER_CLIENT, name = 'iq'},
      [{'type', Type}, {'to', To}, {'id', Id}])
)). 

which would cause an error, I test it like this:
15> exmpp_xml:set_attributes({xmlel, ‘jabber:client’, [], iq, [], []},[{‘type’, get}, {‘to’, “localhost”}, {‘id’, 1234}]).
** exception error: no function clause matching exmpp_xml:set_attribute({xmlel,‘jabber:client’,[],iq,[],[]},type,get)
in function exmpp_xml:set_attributes/2
and when I use binary instead of atom, it’s ok:
18> exmpp_xml:set_attributes({xmlel, ‘jabber:client’, [], iq, [], []},[{<<“type”>>, get}, {<<“to”>>, “localhost”}, {<<“id”>>, 1234}]).
{xmlel,‘jabber:client’,[],iq,
[{xmlattr,undefined,<<“type”>>,<<“get”>>},
{xmlattr,undefined,<<“to”>>,<<“localhost”>>},
{xmlattr,undefined,<<“id”>>,<<“1234”>>}],
[]}

So, anybody can explain this? Is this a bug or something else?

Best regards.

EXMPP not connecting to M-Link XMPP Server - Solved

2011-04-14T20:41:33+01:00

When trying to connect to M-Link XMPP Server

=ERROR REPORT==== 2011-04-14 21:34:30 ===
Error in process <0.107.0> on node ‘JingleNodes@ds0039’ with exit value: {{nocatch,{xml_parser,parsing,parsing_failed,{27,“unbound prefix”}}},[{exmpp_xmlstream,parse,2},{exmpp_socket,receiver_loop,3}]}

=INFO REPORT==== 2011-04-14 21:34:30 ===
application: app_jn_component
exited: {shutdown,{app_jn_component,start,[normal,[]]}}
type: temporary

——-
After:
dbg:tracer().
dbg:p(all,c).
dbg:tpl(exmpp_xmlstream, parse, []).
dbg:tpl(exmpp_internals, gen_send, []).

(<0.140.0>) call exmpp_xmlstream:parse({xml_stream,{gen_fsm,<0.139.0>},
{xml_parser,[{max_size,infinity},
{root_depth,1},
{names_as_atom,true},
{emit_endtag,true},
{check_nss,xmpp},
{check_elems,xmpp},
{check_attrs,xmpp}],
#Port<0.4184>},
new,false,undefined},<<”<stream:error><host-gone ></stream:error></stream:stream><?xml version=‘1.0’?><stream:stream >”>>)

That was a simple type in the component Name.

presence processing branch is missed in stream_opened

2011-01-24T23:29:36+01:00

Hi,

Below is the code from exmpp_session.erl (on github.com):

%% Process incoming
%% Dispatch incoming messages
stream_opened(?message, State = #state{client_pid = From}) ->
process_message(From, Attrs, MessageElement),
{next_state, stream_opened, State};
%% Dispach IQs from server
stream_opened(?iq, State) ->
process_iq(State#state.client_pid, Attrs, IQElement),
{next_state, stream_opened, State};

The branch for ?presence is missed. Is there any specific reason for it? In my case I have stream_opened state after I login, so handling incoming presences should be fine, right?
The fact that presence doesn’t get handled creates received_packet record with most of the fields missed (as presence becomes “other” packet, which is handled by yet another stream_opened branch).

Please advise,

Regards,
Boris

exmpp no_engine_registered Issue on Debian

2009-12-03T21:13:21+01:00

When using exmpp in an old Debian Server I’m getting the following message:

=ERROR REPORT==== 3-Dec-2009::21:10:07 ===
Error in process <0.35.0> with exit value: {{nocatch,{xml_parser,options,no_engine_registered,undefined}},[{exmpp_component,connect,3},{jn_component,init,6}]}

Using latest Erlang OTP Distribution, also using the tar version of exmpp.

Any clues?

exmpp: PEP support in component bots

2010-03-24T00:04:56+01:00

Hi everyone,

I believe it would be great to handle PEP updates by users subscribed to component bots.

Does the auto-subscribe feature of the personal eventing protocol work also with component bots?
Can the component bot use Entity Capabilities to specify which event types wants to receive?

Or is it necessary to explicitly subscribe to peers’ http://jabber.org/protocol/tune node?

I would be really glad if you could please share any clues on the right way to implement PEP handling at the component side.

Thanks a lot!

Cheers,
Vince

exmpp: presence subscription from a component bot

2010-03-21T18:57:58+01:00

Hi All,

Thanks a lot for developing exmpp library in open source!

I was giving it a first try by following the tutorial at http://www.process-one.net/en/blogs/article/scalable_xmpp_bots_with_erlang_and_exmpp_part_iii and running the article source code. Sweet!

I’ve experienced only one problem so far and I’d like to ask for your help… Sorry, I still haven’t figure out what I’m overlooking here.

Right after a successful registration, the web_status_component sends a request to subscribe the user’s presence informations:

<nick >Web Presence Bot</nick></presence>

{xmlel,‘jabber:component:accept’,[],presence,
[{xmlattr,undefined,type,<<“subscribe”>>},
{xmlattr,undefined,from,<<“buddy@example.tld”>>},
{xmlattr,undefined,to,<<“romeo@example.tld”>>}],
[{xmlel,‘http://jabber.org/protocol/nick’,[],nick,[],
[{xmlcdata,<<“Web Presence Bot”>>}]}]}

The server replies back with, stopping the client from exchanging any presence message with the component:

<nick >Web Presence Bot</nick><error code=“400” type=“modify”><bad-request ></error></presence>

Similarly, at component startup presence notifications don’t go through.

Can you please help me in fixing presence subscription handling from a component?

I’m using ejabberd 2.1.x branch with exmpp 0.9.3 and I’d love starting to build a component bot with exmpp :-)

Many thanks!

Best,
Vince

exmpp improvements

2009-06-05T12:55:53+01:00

As exmpp is still work in progress, I guess such a thread is necessary ;)

First thing :
I’m writing some code to connect to a MUC.

The #received_packet{} record is great, but it could be a bit better!

Case in point : the from field. It just holds a string. I’d pretty much rather it to return the jlib:jid_to_lower term :
{Node, Server, Resource}, because ... pattern matching :)

If I am to write a MUC client, I’d like to pattern match on {“room”, “conference.localhost”, Sender} in my receive loop.

That would imply implementing the exmpp_jid:make({Node, Server, Resource}) and the exmpp_jid:to_lower(JID)

This JID representation is so useful in ejabberd (see mod_muc, mod_pubsub) I’d love to have here too.

And while I am at it, I’d like to have several client_pids subscribing to events by pattern matching this same #received_packet{} on sender or query_ns. Of course, I might end up doing it myself, but that would be very nice to have as an option.

Thank you for exmpp

2009-06-04T16:58:37+01:00

You guys made my day yesterday with the release of exmpp. I’m already a happy user.

The code is nice, clean and well documented. The one thing it lacks is a couple of how-to/tutorials to get people started. I’m planning to write a blog post in the future to help folks get started. I’m sure once the library starts getting used more, there will be more of these to guide new users.

One question: do I have to be running ejabberd for my clients to work? I was able to get a client login on my localhost with ejabberd running but when I run the same code with a gmail JID, I am not able to get it to work.

Thanks,

Problem with building exmpp

2009-08-18T00:21:26+01:00

Hello,

I’m trying to build exmpp on Debian, and for some reason configure script doesn’t see neither Expat nor LibXml2, although both of them are installed.

The configuration output shows:

XML parsers:
. Expat: no
. LibXML2: no
Consequently, exmpp_xml:start_parser() throws
{xml_parser,options,no_engine_registered,undefined}
exception.

What am I missing?

Thank you,

Boris

Crash when receiving unexpected Packet

2009-11-19T17:33:05+01:00

Not sure if it is my Erlang, or exmpp crashing here:

22> jn_component:start(“jn.localhost”,“secret”,“localhost”, 8888, “127.0.0.1”).
<0.333.0>
{received_packet,iq,“get”,
{<<“user2”>>,<<“localhost”>>,<<“Thiago-Camargos-MacBook-Pro”>>},
“aacaa”,undefined,
{xmlel,‘jabber:component:accept’,[],iq,
[{xmlattr,undefined,from,
<<“user2@localhost/Thiago-Camargos-MacBook-Pro”>>},
{xmlattr,undefined,to,<<“jn.localhost”>>},
{xmlattr,‘http://www.w3.org/XML/1998/namespace’,“lang”,<<“en”>>},
{xmlattr,undefined,type,<<“get”>>},
{xmlattr,undefined,id,<<“aacaa”>>}],
[{xmlcdata,<<”n”>>},
{xmlel,‘http://jabber.org/protocol/disco#info’,
[{‘http://jabber.org/protocol/disco#info’,none}],
‘query’,[],[]},
{xmlcdata,<<”n”>>}]}}
23>
=ERROR REPORT==== 19-Nov-2009::17:29:56 ===
Error in process <0.333.0> with exit value: {function_clause,[{jn_component,process_iq,[<0.334.0>,{xmlel,‘jabber:component:accept’,[],iq,[{xmlattr,undefined,from,<<43 bytes>>},{xmlattr,undefined,to,<<12 bytes>>},{xmlattr,‘http://www.w3.org/XML/1998/namespace’,“lang”,<<2 bytes>>},{xmlattr,undefined…

—————————————————————————————————
The code portion is:

loop(XmppCom, JID, PubIP) ->
    receive
        stop ->
            exmpp_component:stop(XmppCom);
        %% If we receive a message, we reply with the same message
        Record = #received_packet{packet_type=message, raw_packet=Packet} ->
            io:format("~p~n", [Record]),
            process_message(XmppCom, Packet, JID),
            loop(XmppCom, JID, PubIP);
        Record = #received_packet{packet_type=iq, type_attr=Type, raw_packet=IQ} ->
            io:format("~p~n", [Record]),
            process_iq(XmppCom, IQ, Type, PubIP,exmpp_xml:get_ns_as_atom(exmpp_iq:get_payload(IQ))),
            loop(XmppCom, JID, PubIP);
        Record ->
            io:format("~p~n", [Record]),
            loop(XmppCom, JID, PubIP)
    end.

%% Create Channel and return details
process_iq(XmppCom, "get", IQ, PubIP, ?NS_CHANNEL) ->
    case allocate_relay() of
        {A, B} ->
                Result = exmpp_iq:result(IQ,get_candidate_elem(PubIP, A, B)),
                exmpp_component:send_packet(XmppCom, Result);
        _ ->
                Error = exmpp_iq:error(IQ),
                exmpp_component:send_packet(XmppCom, Error)
        end;

process_iq(XmppCom, "get", IQ, _, ?NS_DISCO_INFO) ->
        Identity = exmpp_xml:element(?NS_DISCO_INFO, 'identity', [exmpp_xml:attribute("category", <<"proxy">>),
                                                      exmpp_xml:attribute("type", <<"relay">>),
                                                      exmpp_xml:attribute("name", <<"Jingle Nodes Relay">>)
                                                      ],
                                     []),
        IQRegisterFeature1 = exmpp_xml:element(?NS_DISCO_INFO, 'feature', [exmpp_xml:attribute('var', ?NS_JINGLE_NODES_s)],[]),
        IQRegisterFeature2 = exmpp_xml:element(?NS_DISCO_INFO, 'feature', [exmpp_xml:attribute('var', ?NS_CHANNEL_s)],[]),
        Result = exmpp_iq:result(IQ, exmpp_xml:element(?NS_DISCO_INFO, 'query', [], [Identity, IQRegisterFeature1, IQRegisterFeature2])),
        exmpp_component:send_packet(XmppCom, Result);

process_iq(XmppCom, "set", IQ, _, _) ->
                    Error = exmpp_iq:error(IQ,'feature-not-implemented'),
                    exmpp_component:send_packet(XmppCom, Error). 