Access global Qt object in javascript file, QML

Question

I defined this javascript function that creates a component and checks, whether it is ready, in one of my QML files:

Item {
    id: lib

    function createCmpt(path) {
        var cmpt = Qt.createComponent(path)
        if (cmpt.status !== Component.Ready) {
            if (cmpt.status === Component.Error) {
                console.error("Error: " + cmpt.errorString())
            }
            console.error("Error: component not ready, path: " + path)
            return null
        }
        return cmpt
    }

    ...
}

Now, I would like to use this function in any of my .qml files (global usage). I know that I can declare this function at the root of my app (ApplicationWindow in my case). But is there a way to define this function maybe in a separate javascript file?
I tried to do that like this (qml.js):

.pragma library

function createCmpt(path) {
    var cmpt = Qt.createComponent(path)
    if (cmpt.status !== Component.Ready) {
        if (cmpt.status === Component.Error) {
            console.error("Error: " + cmpt.errorString())
        }
        console.error("Error: component not ready, path: " + path)
        return null
    }
    return cmpt
}

But of course this does not work, as this seems to be vanilla javascript, which has no knowledge of the global Qt object.

Any ideas, on how I could define this function in my external js file?

UPDATE: I did not read my error message carefully enough! It seems like the global Qt object is indeed known to the javascript. However, Component was not. In the official doc I found a way to import qml namespaces to javascript files and I rewrote my code to:

.pragma library

.import QtQml 2.11 as QtQml

function createCmpt(path) {
    var cmpt = Qt.createComponent(path)
    if (cmpt.status !== QtQml.Component.Ready) {
        if (cmpt.status === QtQml.Component.Error) {
            console.error("Error: " + cmpt.errorString())
        }
        console.error("Error: component not ready, path: " + path)
        return null
    }
    return cmpt
}

However, now I get an error:
QObject::startTimer: Timers cannot be started from another thread
I am not sure what to do with it

Just use a singleton instead.

dtech
– dtech

2018-10-13 13:21:07 +00:00
Commented Oct 13, 2018 at 13:21 — dtech
– dtech, Commented Oct 13, 2018 at 13:21

skaldesh · Accepted Answer · 2018-10-13 18:00:41Z

0

Sorry for answering my own question, but I already found the solution. The code I posted in the update of my question is already what I need:

// qml.js
.pragma library

.import QtQml 2.11 as QtQml

function createCmpt(path) {
    var cmpt = Qt.createComponent(path)
    if (cmpt.status !== QtQml.Component.Ready) {
        if (cmpt.status === QtQml.Component.Error) {
            console.error("Error: " + cmpt.errorString())
        }
        console.error("Error: component not ready, path: " + path)
        return null
    }
    return cmpt
}

The error message with the timer no longer appears, not sure where it came from (I did some other stuff at the same time). So this works now, I can use the Qt stuff with imports in my dedicated javascript files :)

answered Oct 13, 2018 at 18:00

skaldesh

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