Adding inputs/outputs

To send data between components, Pacpus uses input/output system based on signals/slots.

We will try to add to our component called MyComponent:

1. an output named "scan" of type LidarScan,
2. an input named "pose" of type GeoPose2D .

So, add virtual methods overriden from ComponentBase: addInputs() and addOutputs() to the component:

// MyComponent.h

class My Component // ...
{
// ...
protected:
    virtual void addInputs() /* override */;
    virtual void addOutputs() /* override */;
};

// MyComponent.cpp

void MyComponent::addInputs()
{
    // inputs go here
}

void MyComponent::addOutputs()
{
    // outputs go here
}

Adding an output

To add an output, you have to use template method ComponentBase::addOutput<class OutputType, class ComponentType>(const char* outputName):

// MyComponent.cpp

void MyComponent::addOutputs()
{
    // outputs go here
    addOutput<LidarScan, MyComponent>("scan");
}

Adding an input

To add an input, you have to have a method in your class that will process it. It should take as the only argument, a constant reference to the type of the input. In our example, we suppose to have a function declared as follows:

void processPose(GeoPose2D const& pose);

You have to use template method ComponentBase::addInput<class OutputType, class ComponentType, typename ProcessingFunction>(const char* outputName, ProcessingFunction inputProcessingFunction):

// MyComponent.cpp

void MyComponent::addInputs()
{
    // inputs go here
    addInput<GeoPose2D, MyComponent>("pose", &MyComponent::processPose);
}

The second argument is the address (&) of our processing method. You can also use a free function or a functor object, as well as any other callable object, e.g. std::function, boost::function, etc.