no messages received from c++publisher

[beschaef]

Hi Adnan,

Our Goal is to publish a message in C++ and subscribe it in Rust. So our Steps we actually take are:

• We are publishing in an c++ Node some Car infos. The message includes the header, position, speed and acceleration of the car.
• Then we try to subscribe this Topic with our Rust Node.
  with "rostopic echo" we can see that there are messages published, but not our rust node.
• On the other hand if we subscribe to the topic with an c++ oder python node we get the data. We also get the messages if we publish to this topic with a rust node.

If we add the env_logger we get the following messages:

ERROR:rosrust::api::slavehandler: Failed to connect to publisher 'http://Lenovo:34875/': Issue while reading XML-RPC data, for response
Caused by:Failed to parse parameters
Caused by:Failed to parse XML RPC parameter
Caused by:Failed to parse array's children
Caused by:Expected a node named 'value' with 1 child
ERROR:rosrust::api::ros: Failed to subscribe to all publishers of topic '/cars/a/car_connector/PositionUpdate': Issue while reading XML-RPC data, for response
ERROR:rosrust::api::slavehandler: Failed to connect to publisher 'http://Lenovo:34875/': Issue while reading XML-RPC data, for response
Caused by:Failed to parse parameters
Caused by:Failed to parse XML RPC parameter
Caused by:Failed to parse array's children
Caused by:Expected a node named 'value' with 1 child
ERROR:hyper::server: request error = TooLarge

If we change the branch in the Cargo.toml to
rosrust = { git = "https://github.com/adnanademovic/rosrust.git", branch = "xmlrpc-api-rework" }

We get the followed messages if we try to subscribe to the topic

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Error(XmlFormat(Msg("Failed to parse XML-RPC response.")), State { next_error: Some(Expected token &XmlEvent::Characters(ref name) |
&XmlEvent::StartElement { name: OwnedName { local_name: ref name, .. }, .. }, found EndElement(value)), backtrace: None })', /checkout/src/libcore/result.rs:906:4
note: Run with `RUST_BACKTRACE=1` for a backtrace.
benjamin@Lenovo:~/catkin_ws/src/anki/racing$ ./target/debug/racing_ki 
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Error(XmlFormat(Msg("Failed to parse XML-RPC response.")), State { next_error: Some(Expected token &XmlEvent::Characters(ref name) |
&XmlEvent::StartElement { name: OwnedName { local_name: ref name, .. }, .. }, found EndElement(value)), backtrace: None })', /checkout/src/libcore/result.rs:906:4
note: Run with `RUST_BACKTRACE=1` for a backtrace.

[adnanademovic]

Can you give me the msg file you're using, or the name of the message type if it's a standard one?!
So I can try and recreate it

[beschaef]

This is the Message i use.

std_msgs/Header header
uint8 location_id
uint8 road_piece_id
float32 offset_from_road_center_mm
uint16 speed_mm_per_sec
uint8 parsing_flags

uint8 last_recv_lane_change_cmd_id
uint8 last_exec_lane_change_cmd_id
uint16 last_desired_horizontal_speed_mm_per_sec
uint16 last_desired_speed_mm_per_sec

bool reversed_parsed
bool reversed_driving

[adnanademovic]

I diagnosed the issue. I'll try to fix this today.

[adnanademovic]

The xmlrpc-api-rework branch should have that fixed now. I tested it with the message, and it worked. Let me know if it worked out for you!

[beschaef]

Thank your very much, now it's working