Thank you for your interest in contributing to Flet!
git clone https://github.com/flet-dev/flet
(Invoke-WebRequest -Uri https://install.python-poetry.org -UseBasicParsing).Content | py -
Be sure to add %USERPROFILE%\AppData\Roaming\Python\Scripts
to PATH
.
curl -sSL https://install.python-poetry.org | python3 -
cd sdk/python
To install all Flet dependencies and enable the project as editable package run:
poetry install
Create hello.py
file with a minimal Flet program:
import flet
from flet import Page, Text
def main(page: Page):
page.add(Text("Hello, world!"))
flet.app(target=main)
and then run it:
poetry run python hello.py
During the first run Flet Client (flet
) executable will be downloaded from Flet GitHub releases to a user temp directory and then started from there. The version of release to download from is taken from flet/version.py
file.
You should see a new native OS window opened with "Hello, world!" in it.
Pytest should be run with poetry run
:
poetry run pytest
The project uses Black formatting style. All .py
files in a PR must be black-formatted.
Install black
extension for Visualtudio Code: https://marketplace.visualstudio.com/items?itemName=ms-python.black-formatter
IDE-specific Black integration guides:
Enable "pylance" type checking in VS Code.
Open user settings, search by "pylance", scroll down to Python > Analysis: Type checking mode section. Enable basic mode.
Install isort
extension for imports formatting: https://marketplace.visualstudio.com/items?itemName=ms-python.isort
pre-commit is a dev dependency of Flet and is automatically installed by poetry install
.
To install the pre-commit hooks run: poetry run pre-commit install
.
Once installed, every time you commit, pre-commit will run the configured hooks against changed files.
When you run python3 hello.py, you might encounter an error like this:
FileNotFoundError: [Error 2] No such file or directory: '/var/folders/xm/cyv42vbs27gff3s39vy97rx00000gn/T/fletd-0.1.50/fletd'
To resolve the issue, just delete this folder ../T/fletd-0.1.50/fletd
. The folder is the one with the FileNotFound Error encountered earlier.
It should work now.
Add the FLET_VIEW_PATH
and FLET_WEB_PATH
variables to the environment variables or profile scripts for your respective OS, making sure to modify the path accordingly:
- On macOS (in
~/.zprofile
or any other profile script):
# Flet
export FLET_VIEW_PATH="$HOME/{path-to-flet}/flet/client/build/macos/Build/Products/Release"
export FLET_WEB_PATH="$HOME/{path-to-flet}/flet/client/build/web"
-
On Windows (open "System Properties" > "Environment Variables", then add a new environment variable):
- as "Variable name", enter
FLET_VIEW_PATH
, and as "Value",{path-to-flet}\flet\client\build\windows\x64\runner\Release
- as "Variable name", enter
FLET_WEB_PATH
, and as "Value",{path-to-flet}\flet\client\build\web
- as "Variable name", enter
-
On Linux (in
~/.bash_profile
or any other profile script):
# Flet
export FLET_VIEW_PATH="$HOME/{path-to-flet}/flet/client/build/linux/{arch}/release/bundle"
export FLET_WEB_PATH="$HOME/{path-to-flet}/flet/client/build/web"
If you have Microsoft Edge installed and want to use it for debugging Flutter apps:
# Flutter
export CHROME_EXECUTABLE="/Applications/Microsoft Edge.app/Contents/MacOS/Microsoft Edge"
If you added these through the terminal, close that terminal session and create a new one.
Open an instance of your IDE (preferably VS Code) at the flet-dev/flet/client
directory.
First, run printenv | grep FLET
(or gci env:* | findstr FLET
on Windows) in the built-in terminal to make sure everything is set. You should see the above environment variables you set (FLET_VIEW_PATH
, FLET_WEB_PATH
) printed out.
- To build the Flutter client for MacOS, run:
When the build is complete, you should see the Flet bundle in the
flutter build macos
FLET_VIEW_PATH
. (Running it will open a blank window.) - To build the Flutter client for Web, run the below command:
When the build is complete, a directory
flutter build web
client/build/web
will be created.
Now open another instance of VS Code at flet-dev/flet/sdk/python
directory.
Create a new folder preferably named playground
(it has been added to the gitignore) in which you will test your additions.
Try running the below command, where <your-main.py>
is the file to test your additions:
poetry run flet run -w -p 8550 playground/<your-main.py>
You should see http://127.0.0.1:8550/ opened in the browser and also a desktop window with the output of your code.
Making changes to the <your-main.py>
will automatically trigger a hot reload.
Now, switch to your flutter vscode instance and run the below command to start/connect the flet client:
flutter run
then choose your device from the shown options. You will be able to see the debugging outputs of the flet client in this terminal.
-
When you make changes to the flet dart files, you will need to restart/rerun the Flutter client for the changes to take effect in your playground. There are two ways to do this:
- fastest: press the keyboard button
R
while in the client's terminal (pressh
to see all other possible options); - slowest: use
flutter run
as seen previously.
- fastest: press the keyboard button
-
When you make changes to the flet python files, you will need to restart/rerun the Python client for the changes to take effect in the opened flutter applications. This is done with the same command:
poetry run flet run -w -p 8550 playground/<your-main.py>
- Create a new
prepare-{version}
branch in flet-dev/flet repository. - For every package in
packages/flet*
directory:- Update package version to
{version}
inpubspec.yaml
. - Add
# {version}
with new/changed/fixed items intoCHANGELOG.md
. Onlypackages/flet/CHANGELOG.md
should contain real items; other packages could have just a stub.
- Update package version to
- Copy
# {version}
section frompackages/flet/CHANGELOG.md
to the rootCHANGELOG.md
. - Open terminal in
client
directory and runflutter pub get
to update Flet dependency versions inclient/pubspec.lock
. - Create a new
{version}
branch in flet-dev/flet-app-templates repository from a previously released{current-version}
branch. - Create a new
{version}
branch in flet-dev/flet-build-template repository from a previously released{current-version}
branch. - Create
Prepare Flet {version}
PR to merge intomain
branch. - In
Build Flet package for Flutter
job of Flet CI build make sure analysis report of everyflet*
Flutter package has only 1 issue "Publishable packages can't have 'path' dependencies.". - Merge
Prepare Flet {version}
PR. - Create and push new
v{version}
tag (withv
prefix). - Update release notes at
https://github.com/flet-dev/flet/releases/tag/v{version}
.
- Homebrew: https://brew.sh/
After installing homebrew, install xz libraries with it:
brew install xz
- Pyenv. Install with
brew
: https://github.com/pyenv/pyenv?tab=readme-ov-file#unixmacos- Install and switch to the latest Python 3.12:
pyenv install 3.12.6
pyenv global 3.12.6
Setup your shell environment: https://github.com/pyenv/pyenv#set-up-your-shell-environment-for-pyenv
echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.zprofile
echo '[[ -d $PYENV_ROOT/bin ]] && export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.zprofile
echo 'eval "$(pyenv init -)"' >> ~/.zprofile
Ensure Python version is 3.12.6 and location is /Users/{user}/.pyenv/shims/python
:
python --version
which python
- Rbenv. Install with
brew
: https://github.com/rbenv/rbenv?tab=readme-ov-file#homebrew- Install and switch to the latest Ruby:
rbenv install 3.3.5
rbenv global 3.3.5
Ensure Ruby version is 3.3.5 and location is /Users/{user}/.rbenv/shims/ruby
:
ruby --version
which ruby
-
VS Code. Install "Apple silicon" release: https://code.visualstudio.com/download
-
GitHub Desktop: https://desktop.github.com/download/ Open GitHub Desktop app, install Rosetta.
-
Poetry: https://python-poetry.org/docs/#installing-with-the-official-installer
After installing poetry, set PATH:
echo 'export PATH=$HOME/.local/bin:$PATH' >> ~/.zprofile
Check Poetry version and make sure it's in PATH:
poetry --version
- Android Studio for Android SDK required by Flutter: https://developer.android.com/studio
- XCode for macOS and iOS SDKs: https://apps.apple.com/ca/app/xcode/id497799835?mt=12
- FVM - Flutter Version Manager: https://fvm.app/documentation/getting-started/installation Install flutter with fvm:
fvm install 3.24.3
fvm global 3.24.3
Set PATH:
echo 'export PATH=$HOME/fvm/default/bin:$PATH' >> ~/.zprofile