diff options
| author | Ulf Hermann <ulf.hermann@qt.io> | 2022-01-17 11:05:34 +0100 |
|---|---|---|
| committer | Qt Cherry-pick Bot <cherrypick_bot@qt-project.org> | 2022-01-25 21:34:46 +0000 |
| commit | 7d553552a5572f88d685106ba4e4d766daaeabb5 (patch) | |
| tree | b647620ebac8cbac1038566a25c37120c0d9e6b0 /src/qml/doc | |
| parent | c7491542dc17a77b408a64fd825a4a8d37487aa0 (diff) | |
Doc: State that you should type-annotate methods
Change-Id: I0c4d6e7d69e15d56e9af36a4fee11c40959946f2
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
(cherry picked from commit c0179382063f3b408891edaa40b4def09546d64c)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
Diffstat (limited to 'src/qml/doc')
| -rw-r--r-- | src/qml/doc/src/qmllanguageref/syntax/objectattributes.qdoc | 28 |
1 files changed, 21 insertions, 7 deletions
diff --git a/src/qml/doc/src/qmllanguageref/syntax/objectattributes.qdoc b/src/qml/doc/src/qmllanguageref/syntax/objectattributes.qdoc index 6ddd9f30d0..935e4b7673 100644 --- a/src/qml/doc/src/qmllanguageref/syntax/objectattributes.qdoc +++ b/src/qml/doc/src/qmllanguageref/syntax/objectattributes.qdoc @@ -789,7 +789,7 @@ signal for an object type may be defined in an object declaration in a QML document with the following syntax: \code - signal <signalName>[([<type> <parameter name>[, ...]])] + signal <signalName>[([<parameterName>: <parameterType>[, ...]])] \endcode Attempting to declare two signals or methods with the same name in the same @@ -805,10 +805,19 @@ import QtQuick 2.0 Item { signal clicked signal hovered() - signal actionPerformed(string action, var actionResult) + signal actionPerformed(action: string, actionResult: int) } \endqml +You can also specify signal parameters in property style syntax: + +\qml +signal actionCanceled(string action) +\endqml + +In order to be consistent with method declarations, you should prefer the +type declarations using colons. + If the signal has no parameters, the "()" brackets are optional. If parameters are used, the parameter types must be declared, as for the \c string and \c var arguments for the \c actionPerformed signal above. The allowed parameter types @@ -846,7 +855,7 @@ the \c SquareButton.qml file as shown below, with signals \c activated and Rectangle { id: root - signal activated(real xPosition, real yPosition) + signal activated(xPosition: real, yPosition: real) signal deactivated property int side: 100 @@ -872,6 +881,10 @@ SquareButton { } \endqml +Signal handlers don't have to declare their parameter types because the signal +already specifies them. The arrow function syntax shown above does not support +type annotations. + See the \l {Signal and Handler Event System} for more details on use of signals. @@ -911,7 +924,7 @@ registering it as a Q_SLOT of the class. Alternatively, a custom method can be added to an object declaration in a QML document with the following syntax: \code - function <functionName>([<parameterName>[, ...]]) { <body> } + function <functionName>([<parameterName>[: <parameterType>][, ...]]) [: <returnType>] { <body> } \endcode Methods can be added to a QML type in order to define standalone, reusable @@ -919,7 +932,8 @@ blocks of JavaScript code. These methods can be invoked either internally or by external objects. Unlike signals, method parameter types do not have to be declared as they -default to the \c var type. +default to the \c var type. You should, however, declare them in order to +help qmlcachegen generate more performant code, and to improve maintainability. Attempting to declare two methods or signals with the same name in the same type block is an error. However, a new method may reuse the name of an existing @@ -934,7 +948,7 @@ import QtQuick 2.0 Rectangle { id: rect - function calculateHeight() { + function calculateHeight() : real { return rect.width / 2; } @@ -962,7 +976,7 @@ Item { Text { id: label - function moveTo(newX, newY) { + function moveTo(newX: real, newY: real) { label.x = newX; label.y = newY; } |