diff options
Diffstat (limited to 'src/qml/doc/src/qmllanguageref/typesystem/basictypes.qdoc')
| -rw-r--r-- | src/qml/doc/src/qmllanguageref/typesystem/basictypes.qdoc | 33 |
1 files changed, 7 insertions, 26 deletions
diff --git a/src/qml/doc/src/qmllanguageref/typesystem/basictypes.qdoc b/src/qml/doc/src/qmllanguageref/typesystem/basictypes.qdoc index 5144fe219e..53984a440d 100644 --- a/src/qml/doc/src/qmllanguageref/typesystem/basictypes.qdoc +++ b/src/qml/doc/src/qmllanguageref/typesystem/basictypes.qdoc @@ -582,34 +582,15 @@ property is only invoked when the property is reassigned to a different object v QML objects (and certainly not JavaScript object either) and the key-value pairs in \c attributes are \e not QML properties. Rather, the \c items property holds an array of values, and \c attributes holds a set of key-value - pairs. Since they are stored as a set of values, instead of as an object, - their contents \e cannot be modified individually: - - \qml - Item { - property variant items: [1, 2, 3, "four", "five"] - property variant attributes: { 'color': 'red', 'width': 100 } - - Component.onCompleted: { - items[0] = 10 - console.log(items[0]) // This will still be '1'! - attributes.color = 'blue' - console.log(attributes.color) // This will still be 'red'! - } - } - \endqml - - Since it is not possible to individually add or remove items from a list or - object stored in a \c variant, the only way to modify its contents is to - reassign a new value. However, this is not efficient, as it causes the value - to be serialized and deserialized. + pairs. Additionally, since \c items and \c attributes are not QML objects, changing - their individual values do not trigger property change notifications. If - the above example had \c onNumberChanged or \c onAnimalChanged signal - handlers, they would not have been called. If, however, the \c items or - \c attributes properties themselves were reassigned to different values, then - such handlers would be called. + the values they contain does not trigger property change notifications. If + the above example had \c onItemsChanged or \c onAttributesChanged signal + handlers, they would not be called when assigning individual entries in + either property. If, however, the \c items or \c attributes properties + themselves were reassigned to different values, then such handlers would be + called. JavaScript programmers should also note that when a JavaScript object is copied to an array or map property, the \e contents of the object (that is, |