Use loader to load the components come with Qt(ex: Rectangle)

[stereomatching]

A simple example
@
iimport QtQuick 2.0
import QtGraphicalEffects 1.0

Rectangle {
width: 640
height: 480

Loader{
   id: loader

   anchors.fill: parent
}

Component.onCompleted: {
    loader.source("DirectionalBlur.qml")
}

}
@

However, this wouldn't work, is it possible to load the build in qml component by loader?

[JapieKrekel]

I guess the double letter 'i' is a typo in your example.
@
iimport QtQuick 2.0
@

Try changing line 15 to
@
loader.source = "DirectionalBlur.qml"
@