[SOLVED] Binding from javascript

[Fenix Voltres]

I create an item dynamically in js and my question is how can I set binding for that item?

I tried following way, but to no avail:

@var newLine = Qt.createQmlObject('import QtQuick 1.0; import Lines 1.0; Line {/.../}', rootScene)
var newBinding = Qt.createQmlObject('import QtQuick 1.0; Binding {}', newLine)
newBinding.target = newLine
newBinding.property = "startingPoint"
newBinding.value = Qt.point(node.x, node.y)@

It SETS the value properly, but when node's position changes, my line doesn't update.

What's the correct way, if this is not?

[frankcyblogic.de]

You best establish the property bindings from QML. You know that you can instantiate your QML components simply by <code>componentId.createObject(<parent>)</code>?

[minimoog77]

Property binding in JS will be available in Qt 4.7.4. See http://bugreports.qt.nokia.com/browse/QTBUG-14964

[frankcyblogic.de]

I wasn't aware that I could do property bindings in JS.
I'm impressed how QML/JS is evolving!

[Fenix Voltres]

[quote author="minimoog77" date="1302971106"]Property binding in JS will be available in Qt 4.7.4. See http://bugreports.qt.nokia.com/browse/QTBUG-14964[/quote]

That's it, is there any chance for me to get current version of qt 4.7.4 (especially QtQuick 1.1) now?

[DenisKormalev]

Fenix, I think you can use Qt from "gitorious":https://qt.gitorious.org/qt in branch 4.7 (or maybe use master if you want even more experimental features).

[frankcyblogic.de]

QtQuick 1.1 was just recently merged into the Qt 4.7 master. You always get the bleeding edge from the "staging area":https://qt.gitorious.org/+qt-developers/qt/staging (e.g. try branch "qtquick11-stable").

[Fenix Voltres]

Thank you, I compiled qtquick11-stable clone, but it didn't help; I found other workaround, though - if someone would have similar problem (with dynamically created bindings of dynamically created items):

*Firstly I created js stateful lib with declared two variables and assigned some objects to them (no matter what they were, just couldn't be nulls):

@var firstHook = someExistingObject1
var secondHook = someExistingObject2@

*Next I created a wrapper component with my custom Line element including mentioned lib with properties 'startingPoint' and 'endingPoint' binded to these variables:

@import QtQuick 1.0
import Lines 1.0
import "../../js/Curve.js" as CurveFunctions

Line {
id: line
penColor: "red"
penWidth: 2
startingPoint: Qt.point(CurveFunctions.firstHook.x, CurveFunctions.firstHook.y)
endingPoint: Qt.point(CurveFunctions.secondHook.x, CurveFunctions.secondHook.y)
}@

*Then I added two functions to my component which change values of those variables and simulated 1px move back and forth of previous binded objects, so properties could update properly:

@ function setFirst(first) {
CurveFunctions.firstHook = first
someExistingObject1.x += 1
someExistingObject1.x -= 1
}
function setSecond(second) {
CurveFunctions.secondHook = second
someExistingObject2.x += 1
someExistingObject2.x -= 1
}@

and it works. 'someExistingObjects' could have opacity 0.0, or be any accessible objects.
I'm not proud of it, but I wasn't able to figure out some other solution.