# Where is the discauss of register callback and run callback?

**URL:** <https://discourse.openrobotics.org/t/where-is-the-discauss-of-register-callback-and-run-callback/34136>\
**Category:** ROS General\
**Tags:** ros2, design, ros\
**Created:** [October 14, 2023, 12:06pm UTC](https://discourse.openrobotics.org/t/where-is-the-discauss-of-register-callback-and-run-callback/34136 "2023-10-14T12:06:29Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![Samel\_S](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.openrobotics.org/samel_s/32/17171_2.png) [@Samel\_S](https://discourse.openrobotics.org/u/Samel_S)\
**Post date:** [October 14, 2023, 12:06pm UTC](https://discourse.openrobotics.org/t/where-is-the-discauss-of-register-callback-and-run-callback/34136/1 "2023-10-14T12:06:29Z")

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I remember I have read the article about ros client’s register callback and action callback in ros document. It talks about the how to register the callback. Also, it talk about use poller to get callbacks and run or trigger to run callbacks. I want to find it.

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**Author:** ![tomoyafujita](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.openrobotics.org/tomoyafujita/32/6097_2.png) [@tomoyafujita](https://discourse.openrobotics.org/u/tomoyafujita)\
**Post date:** [October 14, 2023, 4:42pm UTC](https://discourse.openrobotics.org/t/where-is-the-discauss-of-register-callback-and-run-callback/34136/2 "2023-10-14T16:42:57Z")

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It would be better to ask questions to [https://robotics.stackexchange.com/](https://robotics.stackexchange.com/), which is our centralized QA site to aggregate questions and answers for the community.

with that said, you can find those tutorials on the public documentation.

> **[Writing a simple service and client (C++) — ROS 2 Documentation: Rolling ...](https://docs.ros.org/en/rolling/Tutorials/Beginner-Client-Libraries/Writing-A-Simple-Cpp-Service-And-Client.html#)**

> **[Writing an action server and client (C++) — ROS 2 Documentation: Rolling ...](https://docs.ros.org/en/rolling/Tutorials/Intermediate/Writing-an-Action-Server-Client/Cpp.html)**

If you have further questions, please consider to post the question to [https://robotics.stackexchange.com/](https://robotics.stackexchange.com/)

thanks,

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**Author:** ![Samel\_S](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.openrobotics.org/samel_s/32/17171_2.png) [@Samel\_S](https://discourse.openrobotics.org/u/Samel_S)\
**Post date:** [October 15, 2023, 12:54pm UTC](https://discourse.openrobotics.org/t/where-is-the-discauss-of-register-callback-and-run-callback/34136/3 "2023-10-15T12:54:52Z")

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I donnot mean to find tutorial to know how to use ros client. That article I want to find is about how to and why ros use that callback desgin. I use ros for many years. I forget where is the article.

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**Author:** ![Samel\_S](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.openrobotics.org/samel_s/32/17171_2.png) [@Samel\_S](https://discourse.openrobotics.org/u/Samel_S)\
**Post date:** [October 15, 2023, 1:02pm UTC](https://discourse.openrobotics.org/t/where-is-the-discauss-of-register-callback-and-run-callback/34136/4 "2023-10-15T13:02:07Z")

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I remember I have read the article about ros client’s register callback and action callback design in ros document. It discusses different ways to register the callback and run callback. Also, it can use poller to get callbacks to run or use trigger to run callbacks. I want to find it.

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**Author:** ![Samel\_S](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.openrobotics.org/samel_s/32/17171_2.png) [@Samel\_S](https://discourse.openrobotics.org/u/Samel_S)\
**Post date:** [October 15, 2023, 1:09pm UTC](https://discourse.openrobotics.org/t/where-is-the-discauss-of-register-callback-and-run-callback/34136/5 "2023-10-15T13:09:44Z")

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I already ask questions to [https://robotics.stackexchange.com/](https://robotics.stackexchange.com/). Thank you for your answer.

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**Author:** ![gbiggs](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.openrobotics.org/gbiggs/32/30361_2.png) [@gbiggs](https://discourse.openrobotics.org/u/gbiggs)\
**Post date:** [October 15, 2023, 11:11pm UTC](https://discourse.openrobotics.org/t/where-is-the-discauss-of-register-callback-and-run-callback/34136/6 "2023-10-15T23:11:57Z")

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Are you referring to the original ROS 2 design investigation articles?

> **[RPC API design in ROS](http://design.ros2.org/articles/ros_rpc.html)**
>
> Distilled design documents related to the ROS 2 effort

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**Author:** ![tfoote](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.openrobotics.org/tfoote/32/3813_2.png) [@tfoote](https://discourse.openrobotics.org/u/tfoote)\
**Post date:** [October 16, 2023, 8:24pm UTC](https://discourse.openrobotics.org/t/where-is-the-discauss-of-register-callback-and-run-callback/34136/7 "2023-10-16T20:24:00Z")

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When you [crosspost questions](https://wiki.ros.org/Support) and if you are directed to do so, make sure to include links to the original postings so that people can have the past context as well.

I’ve found your post here:

[https://robotics.stackexchange.com/questions/104729/where-is-the-discussof-register-callback-and-run-callback-in-ros-design](https://robotics.stackexchange.com/questions/104729/where-is-the-discussof-register-callback-and-run-callback-in-ros-design)

Now that I’ve crosslinked this for peoples reference I’m going to close this as that’s the right place to answer it.

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**Author:** ![tfoote](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.openrobotics.org/tfoote/32/3813_2.png) [@tfoote](https://discourse.openrobotics.org/u/tfoote)\
**Post date:** [October 16, 2023, 8:24pm UTC](https://discourse.openrobotics.org/t/where-is-the-discauss-of-register-callback-and-run-callback/34136/8 "2023-10-16T20:24:09Z")

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