Structure of generated interface

[tylerjw]

description yaml file:

topic: <>
input_rate: <>
updater:
  topic: <>

// namespace is interface library name
namespace foo_config {

struct Params {
  string topic;
  double input_rate;
  struct Updater {
    string topic;
  } updater;

  // for detecting if the parameter struct has been updated
  rclcpp::Time __stamp;
};

class ParamListener {
 public:
  ParamListener(rclcpp::ParameterInterface);
  ParamListener(rclcpp::Node::SharedPtr node) 
    : ParameterListener(node->get_parameters_interface()) {}
  ParamListener(rclcpp_lifecycle::LifecycleNode::SharedPtr node) 
    : ParameterListener(node->get_parameters_interface()) {}
  Params get() const;
  bool is_invalid(Params const& other) const;

 private:
  std::mutex mutex_;
  Params params_;
};

} // namespace foo_config

Use Example

// initalization
auto const node = std::make_shared<rclcpp::Node>("foo");
auto const param_listener = foo_config::ParameterListener(node);
auto params = param_listener.get();

...
// in update loop
if (param_listener.is_invalid(params)) {
  params = param_listener.get();
}

[pac48]

See this commit for change: 028f5d8