How to pass string value to loader iem?

Mr Pang

I have a child.qml which will be loaded by a Loader.
child.qml has a Text
I want to pass a string to Text Dynamically.
How to do it?
Thanks for your guidance！

Mr Pang

I define a property string origName in parent Loader,
child.qml uses parent.origName to reference it.
When I changed the source property of Loader, I got "TypeError: Cannot read property 'origName' of null"
Is this a serious problem?

Charby

Hi, would you please show the code?

Devopia53

@Mr-Pang

Below the methods typically used:

yourLoader.setSource("child.qml", {"text": "yourMessages"}); // "text" is property name on child.qml item

Mr Pang

@Devopia53
Thank you very much.
I am too careless to find out this method.

Charby

I think it would have help to have a complete working code as there many ways to use a loader and passing a string...

Here is a sample with 4 ways :
main.qml

import QtQuick 2.2
import QtQuick.Window 2.1
import QtQuick.Controls 1.2
import QtQml 2.2

Window{
    id:page1
    visible:true;    width:640;    height:480

    Loader{
        id:yourLoader
        property string origName : "orig"
        source:"child.qml"
        anchors.top : button.bottom
    }

    Button{
        id:button
        text:"change"

        onClicked: {
            var curTime = new Date().toTimeString();
            yourLoader.setSource("child.qml", {"text": "text:"+curTime});
            yourLoader.item.text2 = "text2:"+curTime;
            yourLoader.origName = "text3 and text4:"+curTime;
        }
    }
}

and child.qml

import QtQuick 2.0

Item {
    id: root
    property string text : "init 1"
    property string text2 : "init 2"
    property string text3 : yourLoader.origName
    property string text4 : parent ? parent.origName : ""

    Text{
        text : parent.text + "\n" + parent.text2 + "\n" + parent.text3 + "\n" + parent.text4
    }
}

as you can see the 3 first ways are working fine without error whereas the 4th requires to check the validity of parent before accessing its property.