Class Payload

constructor/briefcase.py:387–626

This class manages and prepares a payload with a temporary directory.

@dataclass
class Payload:
    """
    This class manages and prepares a payload with a temporary directory.
    """

    info: dict
    archive_name: str = "payload.tar.gz"
    conda_exe_name: str = "_conda.exe"

    # Enable additional log output during pre/post uninstall/install.
    add_debug_logging: bool = False

    @functools.cached_property
    def root(self) -> Path:
        """Create root upon first access and cache it."""
        return Path(tempfile.mkdtemp(prefix="payload-"))

    def remove(self, *, ignore_errors: bool = True) -> None:
        """Remove the root of the payload.

        This function requires some extra care due to the root directory being a cached property.
        """
        root = getattr(self, "root", None)
        if root is None:
            return
        shutil.rmtree(root, ignore_errors=ignore_errors)
        # Now we drop the cached value so next access will recreate if desired
        try:
            delattr(self, "root")
        except Exception:
            # delattr on a cached_property may raise on some versions / edge cases
            pass

    def prepare(self) -> None:
        """Prepares the payload.

        Directory structure created during preparation:

            <root>/                          (temporary directory, see :attr:`root`)
            ├── welcome.bmp, header.bmp, icon.ico  (branding images for WiX UI, not installed)
            └── <EXTERNAL_PACKAGE_PATH>/     (external_dir: contains the payload archive and conda exe)
                └── base/                    (base_dir: represents the base conda environment)
                    └── pkgs/                (pkgs_dir: staging area for conda package distributions)

        Note: base_dir and pkgs_dir are removed after archiving.
        """
        external_dir = self.root / EXTERNAL_PACKAGE_PATH
        external_dir.mkdir(parents=True, exist_ok=True)

        write_images(self.info, self.root, installer_type="msi")

        # Note that the directory name "base" is also explicitly defined in `run_installation.bat`
        base_dir = external_dir / "base"
        base_dir.mkdir()

        pkgs_dir = base_dir / "pkgs"
        pkgs_dir.mkdir()