QML: Add more overloads to Qt.format{Date|Time|DateTime}()

Since JavaScript has no concept of time or date separate from the Date
object that contains both, and since we implicitly (via
QVariant::convert) or explicitly accept string arguments to all these
methods, we should really accept string coercions of Date objects.

We should also make all the string overloads explicit. Converting
strings to QDateTime is a really obscure feature of the metatype system.
We should not rely on it.

Furthermore, we need to accept QDateTime, as the native representation
of the JavaScript Date object, as argument to formatDate() and
formatTime(). Otherwise there are two ambiguous paths to calling
formatTime() or formatDate() using a Date object: Either coerce the Date
into a string and call the string overload or coerce it into a QTime or
QDate and call the QTime or QDate overload. The QML engine special cases
this and prefers the QTime/QDate way, but this just needlessly
complicates the overload resolution.

Interestingly, tst_qqmlqt already tests most of those variants. We just
have to add the JS string coercions.

Task-number: QTBUG-109380
Change-Id: I880e622256fe115dade32bde880605df2031ff2f
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Sami Shalayel <sami.shalayel@qt.io>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/qml/jsruntime/qv4dateobject_p.h b/src/qml/jsruntime/qv4dateobject_p.h
index 147638744d..ad5b51f063 100644
--- a/src/qml/jsruntime/qv4dateobject_p.h
+++ b/src/qml/jsruntime/qv4dateobject_p.h
@@ -207,6 +207,7 @@ struct DateObject: ReferenceObject {
 
     static QString dateTimeToString(const QDateTime &dateTime, ExecutionEngine *engine);
     static QDate dateTimeToDate(const QDateTime &dateTime);
+    static QDateTime stringToDateTime(const QString &string, ExecutionEngine *engine);
 };
 
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