Skip to content

Downloader#

flet_pkg.core.downloader #

Pub.dev package downloader.

Downloads Flutter package source tarballs from pub.dev with local caching to avoid repeated downloads.

PackageNotFoundError #

Bases: Exception

Raised when a package is not found on pub.dev.

DownloadError #

Bases: Exception

Raised when a download fails.

PackageMetadata dataclass #

PackageMetadata(name: str, version: str, description: str = '', homepage: str = '', repository: str = '')

Metadata for a pub.dev package.

PubDevDownloader #

PubDevDownloader(cache_dir: Path | None = None)

Downloads and caches Flutter packages from pub.dev.

Packages are cached in ~/.cache/flet-pkg/{name}-{version}/ so repeated runs are instantaneous.

Source code in src/flet_pkg/core/downloader.py 
47
48
def __init__(self, cache_dir: Path | None = None):
    self.cache_dir = cache_dir or self.CACHE_DIR

fetch_metadata #

fetch_metadata(package_name: str) -> PackageMetadata

Fetch package metadata from pub.dev.

Parameters:

Name Type Description Default
package_name str

The pub.dev package name.

 required

Returns:

Type Description
PackageMetadata

PackageMetadata with name, version, description, etc.

Raises:

Type Description
PackageNotFoundError

If the package doesn't exist.
DownloadError

On network errors.
Source code in src/flet_pkg/core/downloader.py 
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
def fetch_metadata(self, package_name: str) -> PackageMetadata:
    """Fetch package metadata from pub.dev.

    Args:
        package_name: The pub.dev package name.

    Returns:
        PackageMetadata with name, version, description, etc.

    Raises:
        PackageNotFoundError: If the package doesn't exist.
        DownloadError: On network errors.
    """
    url = self.PUB_API.format(name=package_name)
    try:
        response = httpx.get(url, follow_redirects=True, timeout=30)
    except httpx.HTTPError as e:
        raise DownloadError(f"Failed to fetch metadata for '{package_name}': {e}") from e

    if response.status_code == 404:
        raise PackageNotFoundError(f"Package '{package_name}' not found on pub.dev.")
    if response.status_code != 200:
        raise DownloadError(
            f"Unexpected status {response.status_code} fetching '{package_name}'."
        )

    data = response.json()
    latest = data.get("latest", {}).get("pubspec", {})
    return PackageMetadata(
        name=package_name,
        version=data.get("latest", {}).get("version", ""),
        description=latest.get("description", ""),
        homepage=latest.get("homepage", ""),
        repository=latest.get("repository", ""),
    )

download #

download(package_name: str, version: str | None = None) -> Path

Download a Flutter package source tarball from pub.dev.

Parameters:

Name Type Description Default
package_name str

The pub.dev package name.

 required
version str | None

Specific version to download. If None, uses latest.

 None

Returns:

Type Description
Path

Path to the extracted package directory.

Raises:

Type Description
PackageNotFoundError

If the package doesn't exist.
DownloadError

On network/extraction errors.
Source code in src/flet_pkg/core/downloader.py 
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
def download(self, package_name: str, version: str | None = None) -> Path:
    """Download a Flutter package source tarball from pub.dev.

    Args:
        package_name: The pub.dev package name.
        version: Specific version to download. If None, uses latest.

    Returns:
        Path to the extracted package directory.

    Raises:
        PackageNotFoundError: If the package doesn't exist.
        DownloadError: On network/extraction errors.
    """
    if version is None:
        metadata = self.fetch_metadata(package_name)
        version = metadata.version

    cache_path = self.cache_dir / f"{package_name}-{version}"
    if cache_path.exists() and (cache_path / "lib").exists():
        return cache_path

    url = self.TARBALL_URL.format(name=package_name, version=version)
    with console.status(f"[info]Downloading {package_name} v{version}...[/info]"):
        try:
            response = httpx.get(url, follow_redirects=True, timeout=60)
        except httpx.HTTPError as e:
            raise DownloadError(f"Failed to download '{package_name}': {e}") from e

        if response.status_code == 404:
            raise PackageNotFoundError(
                f"Package '{package_name}' version '{version}' not found."
            )
        if response.status_code != 200:
            raise DownloadError(
                f"Unexpected status {response.status_code} downloading '{package_name}'."
            )

        cache_path.mkdir(parents=True, exist_ok=True)
        tarball_path = cache_path / "package.tar.gz"
        tarball_path.write_bytes(response.content)

        try:
            with tarfile.open(tarball_path, "r:gz") as tar:
                tar.extractall(cache_path, filter="data")
        except tarfile.TarError as e:
            raise DownloadError(f"Failed to extract '{package_name}': {e}") from e
        finally:
            tarball_path.unlink(missing_ok=True)

    return cache_path