Briefcase macOS App Template

A Cookiecutter template for building Python apps that will run under macOS.

Using this template

The easiest way to use this project is to not use it at all - at least, not directly. Briefcase is a tool that uses this template, rolling it out using data extracted from a pyproject.toml configuration file.

However, if you do want use this template directly...

1. Install Cookiecutter. This is a tool used to bootstrap complex project templates:

   $ pip install cookiecutter
   

2. Run cookiecutter on the template:

   $ cookiecutter https://github.com/beeware/briefcase-macOS-app-template
   

   This will ask you for a number of details of your application, including the name of your application (which should be a valid PyPI identifier), and the Formal Name of your application (the full name you use to describe your app). The remainder of these instructions will assume a name of my-project, and a formal name of My Project.

3. Obtain a Python Apple support package for macOS, and extract it into the My Project/My Project.app/Contents/Resources/Suppoort directory generated by the template.

4. Obtain a stub binary, and add it as a file named My Project in the My Project/My Project.app/Contents/MacOS/ directory generated by the template. The stub project in the Briefcase macOS Xcode template generates two stub binaries - one for GUI apps, and one for console apps; copy the appropriate executable from that project into your app template.

5. Add your code to the template, into the My Project/My Project.app/Contents/Resources/app directory. At the very minimum, you need to have an app/<app name>/__main__.py file that defines an entry point that will start your application.

   If your code has any dependencies, they should be installed into the My Project/My Project.app/Contents/Resources/app_packages directory.

If you've done this correctly, a project with a formal name of My Project, with an app name of my-project should have a directory structure that looks something like:

My Project/
    My Project.app/
        Contents/
            MacOS/
                My Project
            Resources/
                app/
                    README
                    my_project/
                        __init__.py
                        __main__.py
                app_packages/
                    README
                    ...
                Support/
                    ...
                    VERSIONS
                my-project.icns
            Info.plist
    installer/
        resources/
            welcome.html
        scripts/
            postinstall
        Distribution.xml
    Entitlements.plist
    briefcase.toml

The My Project.app directory should identify as an macOS application that can be started by clicking on the application icon in Finder. It can also be distributed as a standalone package.

Before you can run the app, you will need to sign any binary files, frameworks and embedded apps in the My Project.app folder, as well as the My Project.app folder itself. The Entitlements.plist file should be a good starting point for the entitlements required to sign the app.

Next steps

Of course, running Python code isn't very interesting by itself - you won't be able to do any console input or output, because a macOS app doesn't display a console.

To do something interesting, you'll need to work with the native macOS system libraries to draw widgets and respond to user input. The Rubicon Objective C bridging library can be used to interface with the macOS system libraries. Alternatively, you could use a cross-platform widget toolkit that supports macOS (such as Toga) to provide a GUI for your application.

If you have any external library dependencies (like Toga, or anything other third-party library), you should install the library code into the app_packages directory. This directory is the same as a site_packages directory on a desktop Python install.