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<!--
SPDX-FileCopyrightText: 2022 Jonah Brüchert <jbb@kaidan.im>
SPDX-License-Identifier: GFDL-1.3-or-later
-->
# QmlTask
{{ doctable("Qml", "QCoroQmlTask") }}
QmlTask allows to return [QCoro::Task][qcoro-task]s directly to QML.
It can be constructed from any [QCoro::Task][qcoro-task] that returns a value that can be converted to a [QVariant][qdoc-qml].
```C++
#include <QCoroQml>
#include <QCoroQmlTask>
int main()
{
...
qmlRegisterType<Example>("io.me.qmlmodule", 1, 0, "Example");
QCoro::Qml::registerTypes();
...
}
class Example : public QObject
{
Q_OBJECT
...
public:
Q_INVOKABLE QCoro::QmlTask fetchValue(const QString &name) const
{
return database->fetchValue(name);
// Returns QCoro::Task<QString>
}
}
```
QmlTasks can call a JavaScript function when they complete:
```QML
Example {
Component.onCompleted: {
fetchValue("key").then((result) => console.log("Result", result))
}
}
```
They can also set properties when the value is available:
```QML
import QCoro 0
import io.me.qmlmodule 1.0
Item {
Example { id: store }
Label {
text: store.fetchValue("key").await().value
}
}
```
[qdoc-qml]: https://doc.qt.io/qt-5/qvariant.html
[qcoro-task]: ../coro/task.md
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