Introduce type based overload of Qt.createComponent

Add type based createComponent overloads based on
QQmlComponent::loadFromModule. They provide a way to instantiate a
component by its type, specified by  a URI and typename pair.
This enables creating Components for inline component types and C++ only
types.
Support for directly passing the type is deferred to a later commit, as
it needs some care to work together with the compiler.

As the string based overload matches a mistaken call to the URL based
createComponent with parent and mode swapped (due to anything being
convertible to string), we add a check to detect this specific error
case and give a helpful error message.

[ChangeLog][QtQml] Qt.createComponent now supports creating a Component
from its module and type name (passed as strings).

Task-number: QTBUG-97156
Fixes: QTBUG-26278
Change-Id: I89e7430fe02d52f57230bfa1b0bfbcbfd0ead4b7
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

1 files changed, 12 insertions, 0 deletions

diff --git a/src/qml/qml/qqmlbuiltinfunctions_p.h b/src/qml/qml/qqmlbuiltinfunctions_p.h
index b961fe6e56..2739524516 100644
--- a/src/qml/qml/qqmlbuiltinfunctions_p.h
+++ b/src/qml/qml/qqmlbuiltinfunctions_p.h
@@ -131,6 +131,12 @@ public:
             const QUrl &url, QQmlComponent::CompilationMode mode = QQmlComponent::PreferSynchronous,
             QObject *parent = nullptr) const;
 
+    Q_INVOKABLE QQmlComponent *createComponent(const QString &moduleUri,
+                                               const QString &typeName, QObject *parent) const;
+    Q_INVOKABLE QQmlComponent *createComponent(const QString &moduleUri, const QString &typeName,
+            QQmlComponent::CompilationMode mode = QQmlComponent::PreferSynchronous,
+            QObject *parent = nullptr) const;
+
     Q_INVOKABLE QJSValue binding(const QJSValue &function) const;
     Q_INVOKABLE void callLater(QQmlV4Function *args);
 
@@ -156,6 +162,12 @@ private:
     QJSEngine *jsEngine() const { return m_engine->jsEngine(); }
     QV4::ExecutionEngine *v4Engine() const { return m_engine; }
 
+    struct Contexts {
+        QQmlRefPointer<QQmlContextData> context;
+        QQmlRefPointer<QQmlContextData> effectiveContext;
+    };
+    Contexts getContexts() const;
+
     QQmlPlatform *m_platform = nullptr;
     QQmlApplication *m_application = nullptr;