CODEWITHSUNDEEP
qtqml
Romy
Romy

Reputation: 407

pass data from one window to another (inside same QML file)

i got two Windows inside the same .qml file.

Window1 has a textinput1 and a button, and when I press the button, i'd like to send the string value from that textinput to the Window2 textInput2.

I'm new to Qt and QML, been reading a lot on signals, Loaders, properties and can't materialize this kind of transfer. Can anyone do a simple 10-line example of such transfer please?

 Window {

        id:window

        TextInput {
            id:text1
            text: "This value is needed in the second Window!"        
        }

        Button {
            onClicked: window2.open()
        }


    Window {
        id.window2

        function open(){
            visible = true
        }            
        Text {
            text: text1.text
        }        
    }
}

If I do this it gives me ReferenceError: text1 is not defined, how can I reference the text1 from the first Window?

Upvotes: 0

Views: 1385

Answers (2)

folibis
folibis

Reputation: 12864

I would prefer to use signals in such case:

Window {
    id: window1
    title: "window 1"
    visible: true
    width: 600
    height: 600
    signal someSignal()

    Button {
        anchors.centerIn: parent
        text: "Open window"
        onClicked: window1.someSignal()
    }

    Window {
        id: window2
        title: "window 2"
        width: 400
        height: 400
        // you can use this instead of Connections
        //Component.onCompleted: {
        //    window1.someSignal.connect(show);
        //}
    }

    Connections {
        target: window1
        onSomeSignal: {
            window2.show();
        }
    }
}

I think this is more ... how do you say? ... more imperative -)

Upvotes: 1

dtech
dtech

Reputation: 49289

i got two Windows inside the same .qml file.

If you did then your code will work. Since it doesn't work, I will assume each window is defined in its own qml file, and you only instantiate the two windows in the same qml file.

If I do this it gives me ReferenceError: text1 is not defined, how can I reference the text1 from the first Window?

You will have to be able to reference the window first, and it should provide an interface to reference the text.

Keep in mind that ideally ids should only be used to reference stuff in the same source. On rare occasions you could go further, and reference ids down the object tree, but only parents, and none of their out-of-line children, it will however work for in-line children that are given ids in that same source. Meaning that if window2 is created inside window then you will be able to reference window from inside window2. But if both windows are siblings in another object, the id won't resolve.

Obj1
  Obj2
    Obj4
  Obj3

In this example object tree, Obj1 will resolve from any of the objects. However, Obj3 will not be able to resolve Obj2 if the id is given inside Obj2, but will resolve if the id for Obj2 is given inside Obj1. But there is no way to resolve Obj4 from Obj3. because the id doesn't act like a property, you can't do someId.someOtherId, that's only possible for properties. You cannot do somePropertyObject.someId neither. You can only begin with either an id or a property, and continue only with sub-properties.

When the id is not applicable, can expose objects or properties either as properties or property aliases. The first is useful when you want to expose a whole object, the second when you want to expose a particular property of an object:

Item {      
  property Item innerItem: inner // gives you access to the "entire" inner object
  property alias innerWidth: inner.width // gives you access to a property of inner

  Item {
    id: inner
  }
}

You can also have aliases to aliases.

Upvotes: 1

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