= 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:

{{{#!c++
// MyComponent.h

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

{{{#!c++
// 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)```:

{{{#!c++
// 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:

{{{#!c++
void processPose(GeoPose2D const& pose);
}}}

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

{{{#!c++
// 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.