enum-key-case.qdoc

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// Copyright (C) 2026 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
 
/*!
\page qmllint-warnings-and-errors-enum-key-case.html
\ingroup qmllint-warnings-and-errors
 
\title Enum key case
\brief [enum-key-case] Enum key starts with a lowercase letter
 
\qmllintwarningcategory enum-key-case
 
\section1 Enum key starts with a lowercase letter
 
\section2 What happened?
An enum contains a key starting with a lowercase letter.
 
\section2 Why is that bad?
It can create ambiguity when performing lookups. Enum keys should start with an uppercase letter
to distinguish them from properties of singletons and attached objects. Not following this
convention can lead to unexpected results.
 
\section2 Example
\qml
// Properties.qml
import QtQuick
 
Item {
    enum Color { red, green, blue }
}
\endqml
\qml
// Main.qml
import QtQuick
 
Item {
    // This lookup could be interpreted as a property lookup on a Singleton or attached object.
    property int i: Properties.green
}
\endqml
 
To fix this warning, rename the key so it starts with an uppercase letter.
 
\qml
// Properties.qml
import QtQuick
 
Item {
    enum Color { Red, Green, Blue }
}
\endqml
\qml
// Main.qml
import QtQuick
 
Item {
    // No ambiguity for the user or the QML engine, this is an enum lookup.
    property int i: Properties.Green
}
\endqml
*/