Cannot assign to non-existent property in another qml file

[houmingc]

error is Cannot assign to non-existent property "marqueeText"
i believe a qml file can call another qml by its filename but i got an error. Please enlighten

@
===============marqueeText.qml==================================
import QtQuick 2.0

Rectangle {

    id:marqueeText
    height: scrollingText.height
    clip: true
    property int tempX: marqueeText.width
    property alias text: scrollingText.text
    Text {
        x: tempX
        id:scrollingText
        color: "Yellow" /* Hard code text color for now */
        font.pixelSize: marqueeText.height - 6;
    }
    Timer {
        id:timer
        interval: 200; running: true; repeat: true
        onTriggered:{
            tempX = tempX - 5
            scrollingText.x = tempX;
            console.debug("Tempx"+ tempX + "TextWidth = " + scrollingText.width, " Height = " + marqueeText.height)

            if( tempX < -scrollingText.width) {
                tempX = marqueeText.width;
                console.debug("Restartlling Text")
            }
           }
    }

}
@
=========main.qml============================
@
import QtQuick 2.2
import QtQuick.Window 2.1
import QtQuick.Layouts 1.1
import QtMultimedia 5.0

Rectangle {
width: 100
height: 620
id: screen

Grid {
    columns: 2
    spacing: 0

    Rectangle {
        id: video;
        color: "black";
        width: 600;
        height: 432
        Video {
            id: videofile
            //playing: true
            source: "video/Bear.wmv"
            width: 600
            height: 432
            opacity: 0.9
            focus: true
            onStopped: {
                videofile.play()
            }
        }
    }
    Rectangle {
        id: picture; width: 200; height: 432
        anchors.left: video.right
        Image {
            source: "pic/phone.jpg"
        }
    }
    Rectangle {
        id: text
        width: 800; height: 48
        color: "blue"
        marqueeText {                       //error
            id:scrolltext
            width: 800
            height: 48
            text: "Qt Quick Digital Signage Demo"
        }
    }

}
}

@

[dvb0222]

Start the class name with an uppercase letter.

I know, pretty non-intuitive.

[houmingc]

you mean id to cap(MarqueeText) or filename & caller in main to cap

[dvb0222]

All three need to start with a cap.

[David Stiel]

You have probably already noticed that the id in marqueeText.qml should not start with an upper case letter as described "here":http://doc.qt.io/qt-5/qtqml-syntax-objectattributes.html#the-id-attribute

I main.qml you do
@
MarqueeText {
id:scrolltext
width: 800
height: 48
text: "Qt Quick Digital Signage Demo"
}
@

This allocates a new instance of the MarqueeText class/element and has nothing to do with the id you provided in the MarqueeText.qml file