This library contains some small helper and convenience functions that may help reduce boilerplate code in ROS2.
To enable easier use of reconfigurable parameters we provide a helper function:
ReconfigurableParameterSubscription subscription = hector::createReconfigurableParameter(
node, "my_parameter",
my_parameter, "A parameter that can be modified",
hector::ReconfigurableParameterOptions<std::string>()
.onValidate([]( const auto &value ) {
return false; /* I HATE UPDATES! */
})
);my_parameter will automatically be kept up to date with value changes as long as the subscription object lives.
Please make sure it does not outlive the node.
Using the hector::Node as base class, we get access to more convenience and thought-through functions e.g. for declaring reconfigurable parameters.
Example:
class MyNode : public hector::Node {
public:
MyNode() : Node("my_node") {
// Declare serial parameters
declare_readonly_parameter( "port_name", port_name_, "Serial port name" );
declare_readonly_parameter( "baud_rate", baud_rate_, "Serial baud rate" );
declare_reconfigurable_parameter(
"controller", controller_type_, "Controller type",
hector::ReconfigurableParameterOptions<std::string>()
.additionalConstraints( "Allowed values: diff_drive" )
.onValidate( []( const auto &value ) { return value == "diff_drive"; } )
.onUpdate( [this]( const std::string &value ) { setupController( value ); } ) );
}
void setupController( const std::string &name ) { /* do something */ }
private:
std::string port_name_ = "/dev/ttyACM0";
int baud_rate_ = 115200;
std::string controller_type_ = "diff_drive";
};The passed parameters are automatically initialized with the parameter value, defaulting to their current value. For reconfigurable parameters, the parameters are also automatically updated. Using the options, you have simplified full control over validation and update callbacks.