qtqml-tooling-qmlls.qdoc

Go to the documentation of this file.

// Copyright (C) 2023 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
 
/*!
\page qtqml-tooling-qmlls.html
\title \QMLLS
\brief A tool that helps you write code in your favorite LSP-supporting editor.
\ingroup qtqml-tooling
\ingroup qtqml-tooling-devtools
 
\QMLLS is a tool shipped with Qt that helps you write code
in your favorite (LSP-supporting) editor.
See \l{https://microsoft.github.io/language-server-protocol/}{Language Server Protocol}
for more information.
 
Currently, it enables your editor to:
\list
    \li Autocomplete your code
    \li Display qmllint warnings
    \li Navigate to definitions in QML files
    \li Find usages of JavaScript variables and QML objects
    \li Rename JavaScript variables and QML objects
    \li Format QML files
    \li Get help from Qt Documentation
\endlist
 
\note \c qmlls is currently in development, see
\l{#Known Limitations}{Known Limitations} for more details.
 
\section1 Supported Features
 
\section2 Linting
 
\QMLLS can automatically lint opened QML files
and display warnings or errors straight in the editor. See
\l{qmllint} for more information about the linting process,
and \l{QML Lint Warning and Errors} on how to fix warnings and
errors.
 
\section2 Formatting
 
\QMLLS can format entire files from inside
the editor. See \l{qmlformat} for more information about the
formatting process.
 
 
\section2 Finding Definitions
 
\QMLLS can find definitions of JavaScript variables,
functions, QML object id's and QML properties from their usages.
 
\QMLLS can also find the definition of types used in
type annotations for JavaScript functions, QML object properties,
and QML object instantiation.
 
\section2 Finding Usages
 
\QMLLS can find usages of JavaScript variables,
QML object properties, JavaScript functions, QML object methods,
and QML object id's.
 
\section2 Renaming
 
\QMLLS can rename JavaScript variables and functions,
as well as QML object properties, methods, and id's, as long as
they are defined in a QML file.
 
\section2 Suggesting Autocompletion Items
 
\QMLLS provides autocompletion suggestions for
JavaScript variables, expressions, and statements, as well as
QML object properties, methods, and id's.
 
\section2 Tracking Changes in C++ Files
 
\QMLLS can track changes in C++ files defining QML
types. It automatically rebuilds CMake QML modules to provide
accurate and up-to-date warnings and completion items for C++
defined QML types.
 
You can
\l{Configuring Automatic CMake Builds}{disable this feature}.
 
\section2 Documentation Hints
 
\QMLLS includes a documentation hints feature that
provides programmers with quick access to Qt’s documentation
by hovering over a keyword. In order to use this feature, your
Qt kit should contain the Qt documentation and your project
should be built with \l{QT_QML_GENERATE_QMLLS_INI} variable.
 
\section1 Setting up \QMLLS in Your Editor
 
This section describes how to develop the \QMLLS client or how to
use your own \QMLLS client.
 
You can find the \QMLLS binary under
\c{<Qt installation folder>/bin/qmlls} in installations of Qt
made with \QOI. If you want your \QMLLS client to download the binary
directly, you can download the standalone version from github via
\l{https://github.com/TheQtCompanyRnD/qmlls-workflow/releases} or
\l{https://qtccache.qt.io/QMLLS/LatestRelease}.
 
\section2 Setting up the Build Directory
 
\QMLLS needs to know the location of the project build folder.
You can pass the build folder in the following ways.
 
\section3 AddBuildDirs LSP Extension
 
To pass build directories via the LSP extension, send a notification
to \QMLLS for the \c{$/addBuildDirs} method. \c{$/addBuildDirs}
accepts one parameter of the form:
\badcode
interface AddBuildDirsParams {
    buildDirsToSet: UriToBuildDirs[];
}
\endcode
where \c{UriToBuildDirs} contains a workspace URI and a list of build
directories.
The workspace URI must designate a workspace advertised to \QMLLS via
\l{https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#workspace_workspaceFolders}{workspaceFolders}
or
\l{https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#workspace_didChangeWorkspaceFolders}{didChangeWorkspaceFolders}.
The build directories are file paths, not URIs.
\badcode
interface UriToBuildDirs {
    baseUri: URI;
    buildDirs: string[];
}
\endcode
 
\section3 --build-dir Command Line Option
 
If you don't need to support multiple workspaces, you can pass the build
directories via the \c{--build-dir} command line option. In this case
your editor should invoke \c{qmlls} as following:
\badcode
<path/to/qmlls> ... --build-dir <path/to/build-directory> ...
\endcode
 
The build directory will be applied to all workspaces if you use multiple
workspaces in the same \QMLLS. The values from \c{addBuildDirsMethod}
have higher precedence than the command line option.
 
\section3 QMLLS_BUILD_DIRS Environment Variable
 
You can also pass the build directories via the \c{QMLLS_BUILD_DIRS}
environment variable. The build directory will be applied to all
workspaces if you use multiple workspaces in the same \QMLLS.
The values from \c{--build-dir} have higher precedence than the
environment variable.
 
\section3 \c{.qmlls.ini} Settings File
 
If you can't pass the build directories using one of the previous options,
you could try passing build directories to \QMLLS via a configuration file.
See also \l{Configuration File}.
The values from the settings file have lower precedence than
\c{--build-dir}, \c{QMLLS_BUILD_DIRS}, and \c{addBuildDirsMethod}.
 
\section2 Configuring Automatic CMake Builds
 
\QMLLS will try to trigger a CMake rebuild when it detects that the
source code of a C++ defined QML type has been modified.
 
To disable this feature, use the following ways:
\list
    \li The \c{--no-cmake-calls} command line option. In this case
your editor should invoke \c{qmlls} as follows:
\badcode
<path/to/qmlls> --build-dir <path/to/build-directory> --no-cmake-calls
\endcode
    \li The \c{QMLLS_NO_CMAKE_CALLS} environment variable.
    \li The \c{.qmlls.ini} settings file, see \l {Configuration File}.
    \li The \l{QT_QML_GENERATE_QMLLS_INI_NO_CMAKE_CALLS} CMake variable
if \l{QT_QML_GENERATE_QMLLS_INI} is enabled.
\endlist
 
To control the number of jobs used by CMake, use
\list
    \li The \c{--cmake-jobs} command line option. In this case
your editor should invoke \c{qmlls} as follows:
\badcode
<path/to/qmlls> --build-dir <path/to/build-directory> --cmake-jobs <jobs>
\endcode
    \li The \c{QMLLS_CMAKE_JOBS} environment variable.
    \li The \c{.qmlls.ini} settings file, see \l {Configuration File}.
\endlist
Accepted values are integers greater than 0 and \c{max} to use all available
cores.
 
\section2 Modifying the maximum amount of files to search
 
\QMLLS respects a limit of files to search when searching the source
folders for headers, for example when going to the definition of a QML
component defined in a C++ header.
 
To set the maximum amount of files to search, write a numeric value in the
\c QMLLS_MAX_FILES_TO_SEARCH environment variable. 0 disables the file
searching feature, 20000 is the default value.
 
\section1 Configuration File
 
\QMLLS can be configured via a configuration file \c{.qmlls.ini}.
This file should be in the root source directory of the project.
It should be a text file in the ini-format.
 
The configuration file can have the following entries:
\code
// .qmlls.ini
[General]
no-cmake-calls=<true-or-false>
CMakeJobs=<some integer value>
 
buildDir=<path/to/build-directory> # not required in Qt 6.10 and later
docDir=<path/to/qt-documentation>  # not required in Qt 6.10 and later
importPaths=<path/to/imports>      # not required in Qt 6.10 and later
\endcode
 
To use the configuration file to disable the automatic CMake rebuild
functionality, set \c{no-cmake-calls} to \c{true}.
 
To control the number of jobs used by automatic CMake rebuilds, set the
CMakeJobs value.
 
To support clients that can't pass the build directory to \QMLLS, as
described in \l{Setting up the Build Directory}, set the buildDir value
or let CMake generate the .qmlls.ini via \l {QT_QML_GENERATE_QMLLS_INI}.
 
\note \QMLLS can create default configuration files
using the \c{--write-defaults} option. This will overwrite an
already existing .qmlls.ini file in the current directory.
 
\section1 Known Limitations
 
Despite covering many common QML features, \QMLLS is still in development with some features
yet to be supported:
\list
    \li Suggesting autocompletions on invalid QML files.
    \li Navigating to definitions of objects defined in C++.
    \li Autocompleting context properties
\endlist
 
\QMLLS might emit false positive warnings on projects
\list
    \li using QMake or imperative type registration---see \l{Port QML modules to CMake}
    \li that were not built---\QMLLS uses the build information to find QML modules
    \li where QML modules don't follow the guidelines in \l{Modernizing QML Modules}
\endlist
 
*/