Add QJSValue::deleteProperty() function

This makes it possible to delete a property without relying on passing
a QJSValue of invalid type to setProperty() (the invalid type is going
to be removed).

Task-number: QTBUG-23604
Change-Id: I653b3349050ad1aac1cf6ccc8547c753abbb9f1d
Reviewed-by: Simon Hausmann <simon.hausmann@nokia.com>
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@nokia.com>

2 files changed, 30 insertions, 1 deletions

diff --git a/src/declarative/qml/v8/qjsvalue.cpp b/src/declarative/qml/v8/qjsvalue.cpp
index 9980463a8f..9d21a1db28 100644
--- a/src/declarative/qml/v8/qjsvalue.cpp
+++ b/src/declarative/qml/v8/qjsvalue.cpp
@@ -915,7 +915,7 @@ QJSValue QJSValue::property(quint32 arrayIndex) const
   built-in properties, such as the \c{length} property of Array objects
   or meta properties of QObject objects.
 
-  \sa property()
+  \sa property(), deleteProperty()
 */
 void QJSValue::setProperty(const QString& name, const QJSValue& value)
 {
@@ -944,6 +944,33 @@ void QJSValue::setProperty(quint32 arrayIndex, const QJSValue& value)
 }
 
 /*!
+  Attempts to delete this object's property of the given \a name.
+  Returns true if the property was deleted, otherwise returns false.
+
+  The behavior of this function is consistent with the JavaScript
+  delete operator. In particular:
+
+  \list
+  \o Non-configurable properties cannot be deleted.
+  \o This function will return true even if this object doesn't
+     have a property of the given \a name (i.e., non-existent
+     properties are "trivially deletable").
+  \o If this object doesn't have an own property of the given
+     \a name, but an object in the prototype() chain does, the
+     prototype object's property is not deleted, and this function
+     returns true.
+  \endlist
+
+  \sa setProperty(), hasOwnProperty()
+*/
+bool QJSValue::deleteProperty(const QString &name)
+{
+    Q_D(QJSValue);
+    QScriptIsolate api(d->engine());
+    return d->deleteProperty(name);
+}
+
+/*!
   Returns true if this object has a property of the given \a name,
   otherwise returns false.
 
diff --git a/src/declarative/qml/v8/qjsvalue.h b/src/declarative/qml/v8/qjsvalue.h
index 756081d842..280f44e924 100644
--- a/src/declarative/qml/v8/qjsvalue.h
+++ b/src/declarative/qml/v8/qjsvalue.h
@@ -134,6 +134,8 @@ public:
     QJSValue property(quint32 arrayIndex) const;
     void setProperty(quint32 arrayIndex, const QJSValue &value);
 
+    bool deleteProperty(const QString &name);
+
     QJSValue::PropertyFlags propertyFlags(const QString &name) const;
 
     QJSValue call(const QJSValue &thisObject = QJSValue(),