How to assign a function definition to a property in QML1 (QtQuick 1.1)?

[imran20487]

MyItem.qml

import QtQuick 1.1
Rectangle{      
  property variant funcDelegate
  function processRequest(){
     funcDelegate()//This call throws error with approach 1
  }
}

I have tried these below 2 approaches (not working)

Approach 1:

TypeError: Result of expression 'funcDelegate' [undefined] is not a function.

Main.qml

import QtQuick 1.1
Item{
  width: 600
  height: 600
  focus: true
  
  MyItem{

    Component.onCompleted: {
       funcDelegate = process
    }

    function process() {
       ...
    }
  }
}

Approach 2:

I get the error when compiling

Error: Unable to assign a function to a property.

Main.qml

import QtQuick 1.1
Item{
  width: 600
  height: 600
  focus: true
  MyItem{
    //assign the property with a function (This works in Qt5 not in 
      Qt 4)
    funcDelegate : function process(){
                      ...
                   }
  }
}

[J.Hilk]

@imran20487 you call functions with the actual parenthesize attached.

try

Component.onCompleted: {
       funcDelegate = process()
    }

process also needs to have an actuall return value

function process() {
       ...
       return something
    }

[imran20487]

I can't call it with the actual paranthesis, because it would call that function immediately. What I want is that it should be called by MyItem.qml in ProcessRequest() as a callback

[Maheshdev305]

@imran20487 the below code works well. try it yourself.

Item {
 id: rootItem
 property var funcPtr

    function test1() {
        console.log("Test 1")
    }
    function test2() {
        console.log("Test 2")
    }
 function processSomething() {
        funcPtr()
    }

    Row {
        Rectangle {
            height: 50
            width: 50
            color:"Red"

            MouseArea {
                anchors.fill: parent
                onClicked: {
                    rootItem.funcPtr = test1
                    rootItem.funcPtr()
                }
            }
        }
        Rectangle {
            height: 50
            width: 50
            color:"blue"

            MouseArea {
                anchors.fill: parent
                onClicked: {
                    rootItem.funcPtr = test2
                    rootItem.funcPtr()
                }
            }
        }
    }
}

Either you can call the var funcPtr directly, or alternatively you can use it in another function like processSomething().
Before using funcPtr, check if it is undefined, or else, it might behave unexpectedly.

[imran20487]

@Maheshdev305 Thanks for the reply, your solution works for QML2 (QT5, QtQuick 2) since 'var' type is avialable, my problem is with QML1 (QT4, QtQuick 1) where 'var' type is not available.