qtqml-tooling-qmlformat.qdoc

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// Copyright (C) 2023 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
 
/*!
\page qtqml-tooling-qmlformat.html
\title qmlformat
\brief A tool that automatically formats QML files according to QML coding convention.
\ingroup qtqml-tooling
\ingroup qtqml-tooling-devtools
 
\section1 qmlformat
\e qmlformat is a tool that automatically formats QML files in accordance
with the \l{QML Coding Conventions}.
 
\table
\header
    \li Usage:
\row
    \li qmlformat [\l{options}] \l{arguments}
\endtable
 
\section2 Options and settings
\target options
qmlformat can be configured via command line options. There are two groups of options: Those which
are directly related to formatting, and those which control the behavior of the tool.
 
 
The following options only affect the tool behavior:
\table
\header
    \li Command Line Option
    \li Description
\row
    \li \c{-h}, \c{--help}
    \li Displays help on commandline options.
\row
    \li \c{--help-all}
    \li Displays help, including generic Qt options.
 
\row
    \li \c{-v}, \c{--version}
    \li Displays version information.
\row
    \li \c{-V}, \c{--verbose}
    \li Verbose mode. Outputs more detailed information.
\row
    \li \c{--write-defaults}
    \li Writes defaults settings to .qmlformat.ini and exits
        (Warning: This will overwrite any existing settings and comments!)
\row
    \li \c{--output-options}
    \li
    \li Output all available options, their default value and a hint of values or types
\row
    \li \c{--ignore-settings}
    \li Ignores all settings files and only takes command line options into consideration
\row
    \li \c{-i}, \c{--inplace}
    \li Edit file in-place instead of outputting to stdout.
\row
    \li \c{-f}, \c{--force}
    \li Continue even if an error has occurred.
\row
    \li \c{-F}, \c{--files <file>}
    \li Format all files listed in file, in-place
\endtable
 
The next group of options controls how files should be formatted, and can additionally also be
controlled via a  \l{Settings File}{settings file}.:
\table
\header
    \li Command Line Option
    \li Setting Name
    \li Default State/Value
    \li Description
\row
    \li \c{-t}, \c{--tabs}
    \li UseTabs
    \li disabled/false
    \li Use tabs instead of spaces.
 
        In a command line invocation, the behavior can be enabled by passing the flag.
 
        In a settings file, the behavior can be enabled by setting the
        relevant variable to "true".
\row
    \li \c{-w}, \c{--indent-width <width>}
    \li IndentWidth
    \li 4
    \li How many spaces are used when indenting.
\row
    \li \c{-W}, \c{--column-width <width>}
    \li MaxColumnWidth
    \li -1
    \li Breaks the line into multiple lines if it exceeds
        the specified width. Use -1 to disable line
        wrapping. (default).
\row
    \li \c{-n}, \c{--normalize}
    \li NormalizeOrder
    \li disabled/false
    \li Reorders and sorts the attributes of the objects according to the QML Coding Guidelines.
        Incompatible with \c{--group-attributes-together}.
 
        In a command line invocation, the behavior can be enabled by passing the flag.
 
        In a settings file, the behavior can be enabled by setting the
        relevant variable to "true".
\row
    \li \c{-l}, \c{--newline <newline>}
    \li NewlineType
    \li native
    \li Overrides the new line format to use (\c {native}, \c {macos}, \c {unix}, \c {windows}).
\row
    \li \c{-S}, \c{--sort-imports}
    \li SortImports
    \li disabled/false
    \li Sort imports alphabetically
        (Warning: this might change semantics if a given name identifies types in multiple modules!).
 
        In a command line invocation, the behavior can be enabled by passing the flag.
 
        In a settings file, the behavior can be enabled by setting the
        relevant variable to "true".
\row
    \li \c{--objects-spacing}
    \li ObjectsSpacing
    \li disabled/false
    \li Ensure spaces between objects (only works with \c{normalize} or \c{group-attributes-together}).
 
        In a command line invocation, the behavior can be enabled by passing the flag.
 
        In a settings file, the behavior can be enabled by setting the
        relevant variable to "true".
\row
    \li \c{--functions-spacing}
    \li FunctionsSpacing
    \li disabled/false
    \li Ensure spaces between functions (only works with \c{normalize} or \c{group-attributes-together}).
 
        In a command line invocation, the behavior can be enabled by passing the flag.
 
        In a settings file, the behavior can be enabled by setting the
        relevant variable to "true".
\row
    \li \c{--group-attributes-together}
    \li GroupAttributesTogether
    \li disabled/false
    \li Reorders but does not sort the attributes of the objects according to the QML Coding Guidelines.
        Incompatible with \c{--normalize}.
 
        In a command line invocation, the behavior can be enabled by passing the flag.
 
        In a settings file, the behavior can be enabled by setting the
        relevant variable to "true".
\row
    \li \c{--single-line-empty-objects}
    \li SingleLineEmptyObjects
    \li disabled/false
    \li Write empty objects on a single line (only works with \c{normalize} or \c{group-attributes-together}).
 
        In a command line invocation, the behavior can be enabled by passing the flag.
 
        In a settings file, the behavior can be enabled by setting the
        relevant variable to "true".
\row
    \li \c{--semicolon-rule}
    \li SemicolonRule
    \li always
    \li Customizes the addition of semicolons at the end of JS statements (\c {always}, \c {essential}).
        \note See \l{Semicolon Rule} for more details.
\endtable
 
\section2 Arguments
\target arguments
\table
\header
    \li Arguments:
\row
    \li filenames
\endtable
 
\section2 Details
\e qmlformat is flexible and can be configured according to your needs.
 
\section3 Output
qmlformat writes the formatted version of the file to stdout.
If you wish to have your file updated in-place specify the \c{-i} flag.
 
\section3 Grouping Properties, Functions, and Signals Together
With \c{-n} or \c{--normalize} flag, \e qmlformat groups and sorts all properties, functions,
and signals by name, instead of retaining the existing order.
For example:
\qml
import QtQuick
 
QtObject {
    signal s2()
    property int h
    function z() {}
    property int w
    function y() {}
    id: asdf
    signal s1()
 
    property Item myItem2: Item {
        TextEdit {}
        Rectangle {}
    }
    property Item myItem: Item {
        Rectangle {}
        TextEdit {}
    }
}
\endqml
 
will be formatted to:
\qml
import QtQuick
 
QtObject {
    id: asdf
 
    property int h
    property Item myItem: Item {
        Rectangle {
        }
        TextEdit {
        }
    }
    property Item myItem2: Item {
        TextEdit {
        }
        Rectangle {
        }
    }
    property int w
 
    signal s1
    signal s2
 
    function y() {
    }
    function z() {
    }
}
\enqml
 
To group the attributes without sorting by name, use \c{--group-attributes-together} instead.
This formats the previous snippet into:
\qml
import QtQuick
 
QtObject {
    id: asdf
 
    property int h
    property int w
    property Item myItem2: Item {
        TextEdit {
        }
        Rectangle {
        }
    }
    property Item myItem: Item {
        Rectangle {
        }
        TextEdit {
        }
    }
 
    signal s2
    signal s1
 
    function z() {
    }
    function y() {
    }
}
\endqml
 
Note that this option takes precedence over \c{--normalize}.
 
 
\section3 Settings File
You can configure \e qmlformat by including a settings file \c{.qmlformat.ini} in your
project source or in the parent directories of your project source folder. A default
settings file can be obtained by passing the \c{--write-defaults} flag. This generates the
\c{.qmlformat.ini} file in the current working directory.
 
\warning \c{--write-defaults} will overwrite any existing settings and comments!
 
\section3 Formatting a List of Files
While you can pass a list of files to be formatted as arguments, qmlformat provides
\c {-F} option to format a set of files stored in a file. In this case, formatting will happen
inplace.
 
\code
    // FileList.txt
    main.qml
    mycomponent.qml
\endcode
 
Then, use it like
\code
    qmlformat -F FileList.txt
\endcode
 
\note If the file contains an invalid entry, for example, a file path that
doesn't exist or a valid file path but the content is an invalid qml document,
then \c qmlformat will error out for that particular entry. It will still format
the valid file entries in place.
 
\warning If you provide -F option, qmlformat will ignore the positional arguments.
 
\section3 Semicolon Rule
The \c{--semicolon-rule} option allows you to customize the addition of semicolons at the end of JS statements.
The following values are accepted:
\list
    \li \c{always} - Always add semicolons (default).
    \li \c{essential} - Remove semicolons unless omitting them would cause issues.
\endlist
 
\section2 Disabling Formatting with Comments
You can temporarily disable qmlformat using special comments.
\list
    \li \c {// qmlformat off} turns off formatting from that line onward
    \li \c {// qmlformat on} turns on formatting after you turned it off
\endlist
 
This lets you preserve hand-tuned code or complex structures without \c qmlformat
changing their layout. Formatting remains off until the next \c {// qmlformat on}
comment, or until the end of the file if no re-enable is found.
 
\note Directives must be on their own line.
 
\note Nested directives are not supported. Only the first \c {// qmlformat off} and
the next \c {// qmlformat on} are considered. Any additional directives inside a disabled
region are ignored.
 
\note The directives are ignored in normalized formatting mode, when \c sortImports is
enabled, or when any option that reorders the original document is used. In these cases,
formatting is always applied.
 
*/