rpc server send formatted string

[rlober]

Hello all,

I have an RpcServer running and when a client is connected and requests the string help I put a formatted string in a bottle and then send that in the reply. Unfortunately when I try to use this functionality from the command line, i.e.

yarp rpc /server_port/rpc:i
>> help

The output is,

Response: "The help string with all escape sequences e.g. '\n' as plain text..."

I assume this is because the yarp rpc tool just automatically calls the toString() method on the reply?

Is there any way to send the string so that the user gets the reply with the formatting? Do I need to define a datatype and overload the toString() method?

Here is the relevant code: https://github.com/robotology/codyco-modules/blob/jtc_mods/src/devices/jointTorqueControl/JointTorqueControl.cpp#L85-L109

Thanks in advance!

[pattacini]

Hi @rlober

I'd point you to https://github.com/robotology/QA/issues/132. Let's comment further therein, if you'll have other doubts.

Thus, closing here.

[rlober]

@pattacini Beautiful! Thanks man.

for the lazy:

solution

std::string bigString = // Format big string;
replyBottle.addVocab(yarp::os::Vocab::encode("many"));  // The magical command.
replyBottle.addString(bigString);

Output goes from:

Response: "\n===============\nValid Commands\n===============\nNote: Omit the brackets [] when writing your commands.\n\n[save] [location] - saves all current parameters to a txt file at the specified [location] (defaults to ./).\n[get] [joint_list] - returns a list of strings with the joint labels.\n[get] [no_joints] - returns the number of joints in the part.\n[get] [params] [joint_index] - get all parameter values for a joint index.\n[get] [param_id] [joint_index] - get the parameter value for a joint index.\n[set] [joint_index] [param_id] [param_value] [param_id] [param_value] ... - set the parameter value(s) for a joint index.\n\n  Valid [param_id] values:\n  --> kp - proportional gain (Joint Torque Loop)\n  --> ki - integral gain (Joint Torque Loop)\n  --> kd - proportional gain (Joint Torque Loop)\n  --> max_int - ??? (Joint Torque Loop)\n  --> max_pwm - ??? (Joint Torque Loop)\n  --> kv - proportional gain ??? (Motor Parameters)\n  --> kcp - ??? (Motor Parameters)\n  --> kcn - ??? (Motor Parameters)\n  --> coulombVelThr - ??? (Motor Parameters)\n  --> kff - feed-forward gain for gravity compensation torque (Motor Parameters)\n  --> frictionCompensation - coefficient of friction compensation (0-1) (Motor Parameters)\n"

to...

Responses:

===============
Valid Commands
===============
Note: Omit the brackets [] when writing your commands.

[save] [location] - saves all current parameters to a txt file at the specified [location] (defaults to ./).
[get] [joint_list] - returns a list of strings with the joint labels.
[get] [no_joints] - returns the number of joints in the part.
[get] [params] [joint_index] - get all parameter values for a joint index.
[get] [param_id] [joint_index] - get the parameter value for a joint index.
[set] [joint_index] [param_id] [param_value] [param_id] [param_value] ... - set the parameter value(s) for a joint index.

  Valid [param_id] values:
  --> kp - proportional gain (Joint Torque Loop)
  --> ki - integral gain (Joint Torque Loop)
  --> kd - proportional gain (Joint Torque Loop)
  --> max_int - ??? (Joint Torque Loop)
  --> max_pwm - ??? (Joint Torque Loop)
  --> kv - proportional gain ??? (Motor Parameters)
  --> kcp - ??? (Motor Parameters)
  --> kcn - ??? (Motor Parameters)
  --> coulombVelThr - ??? (Motor Parameters)
  --> kff - feed-forward gain for gravity compensation torque (Motor Parameters)
  --> frictionCompensation - coefficient of friction compensation (0-1) (Motor Parameters)

[pattacini]

Btw @rlober, did you know that with Thrift you'll have rpc services documentation automagically done for you? :wink:

[rlober]

@pattacini very interesting! I will have to play with this tool.