{"id":6074,"library":"pyobjc-framework-backgroundassets","title":"PyObjC Framework: BackgroundAssets","description":"Python wrappers for the macOS BackgroundAssets framework, enabling applications to manage large asset downloads in the background. It is part of the comprehensive PyObjC project, which provides Python bindings for the entire macOS and iOS Cocoa frameworks. Version 12.1 is the latest stable release, with updates typically aligned with macOS SDK releases and Python version support.","status":"active","version":"12.1","language":"en","source_language":"en","source_url":"https://github.com/ronaldoussoren/pyobjc","tags":["macos","framework","pyobjc","background-downloads","apple"],"install":[{"cmd":"pip install pyobjc-framework-backgroundassets","lang":"bash","label":"Install package"}],"dependencies":[{"reason":"Provides the core bridge between Python and Objective-C, essential for all PyObjC framework bindings.","package":"pyobjc-core"},{"reason":"Provides core macOS Foundation classes like NSURL, often used in conjunction with other frameworks.","package":"pyobjc-framework-Foundation","optional":true}],"imports":[{"symbol":"BAManager","correct":"from BackgroundAssets import BAManager"},{"symbol":"BAURLDownload","correct":"from BackgroundAssets import BAURLDownload"},{"symbol":"BAURLDownloadConfiguration","correct":"from BackgroundAssets import BAURLDownloadConfiguration"},{"symbol":"NSURL","correct":"import Foundation"}],"quickstart":{"code":"import Foundation\nfrom BackgroundAssets import BAManager, BAURLDownload, BAURLDownloadConfiguration, BAURLDownloadNetworkActivityCellular\n\n# Get the shared manager instance\nmanager = BAManager.sharedManager()\n\n# Create a configuration for the download\nconfig = BAURLDownloadConfiguration.new()\nconfig.setIdentifier_(\"com.example.mybackgrounddownload\") # Unique identifier\nconfig.setDiscretionary_(True) # Allow system to decide when to run\nconfig.setRequiresPower_(False) # Does not require external power\nconfig.setRequiresNetworkActivity_(BAURLDownloadNetworkActivityCellular) # Or BAURLDownloadNetworkActivityAny, BAURLDownloadNetworkActivityWiFi\n\n# Create a URL for the download (replace with a real URL for testing)\ndownload_url_str = \"https://example.com/some/large/file.zip\"\ndownload_url = Foundation.NSURL.URLWithString_(download_url_str)\n\n# Create the download object\n# The last argument is an NSError** pointer; use None for Python in non-error cases\ndownload, error = BAURLDownload.downloadWithURL_configuration_error_(download_url, config, None)\n\nif download:\n    print(f\"Successfully created BAURLDownload: {download.identifier()}\")\n    print(f\"Download URL: {download.URL().absoluteString()}\")\n    print(f\"Configuration identifier: {download.configuration().identifier()}\")\n    \n    # To actually schedule it, you'd add it to the manager. This often requires\n    # specific macOS entitlements and an application lifecycle.\n    # For a simple runnable snippet, just creating the objects is sufficient.\n    # success, error_add = manager.addDownload_error_(download, None)\n    # if success: print(f\"Added download to manager.\")\n    # else: print(f\"Failed to add download: {error_add}\")\nelse:\n    print(f\"Failed to create BAURLDownload: {error}\")","lang":"python","description":"This example demonstrates how to create a `BAURLDownloadConfiguration` and a `BAURLDownload` object using the `BackgroundAssets` framework. Note that actually initiating and managing background downloads requires specific macOS application entitlements and a properly configured application delegate, which are outside the scope of a simple Python script."},"warnings":[{"fix":"Ensure your project uses Python 3.10 or later for PyObjC v12.x, or Python 3.9 or later for PyObjC v11.x.","message":"PyObjC has dropped support for older Python versions in recent releases. Python 3.9 support was dropped in v12.0, and Python 3.8 support was dropped in v11.0.","severity":"breaking","affected_versions":">=11.0"},{"fix":"Develop and run PyObjC projects exclusively on macOS. If encountering installation issues, ensure your Python installation matches your macOS architecture and that Xcode command-line tools are installed (`xcode-select --install`).","message":"PyObjC is a macOS-specific library and will not work on other operating systems. Furthermore, `pyobjc-core` is a compiled extension and requires a compatible Python version and macOS architecture (e.g., Apple Silicon vs. Intel).","severity":"gotcha","affected_versions":"all"},{"fix":"Review initialization logic for any Python-defined Objective-C classes, especially those overriding `init...` methods, to ensure correct reference counting and object lifetime management.","message":"PyObjC 11.1 introduced changes to align Automatic Reference Counting (ARC) behavior for initializer methods with Clang's documentation. This can affect how custom Objective-C classes, or classes subclassed in Python, handle object references during initialization.","severity":"breaking","affected_versions":">=11.1"},{"fix":"When developing a macOS application using BackgroundAssets, ensure the necessary entitlements are added to your application's `Info.plist` or Xcode project settings. Simple Python scripts run without an application bundle may have limited functionality.","message":"The BackgroundAssets framework, like many macOS background services, typically requires specific application entitlements (e.g., `com.apple.developer.background-downloads`) configured in your Xcode project for full functionality. Without these, downloads may not proceed.","severity":"gotcha","affected_versions":"all"}],"env_vars":null,"last_verified":"2026-04-14T00:00:00.000Z","next_check":"2026-07-13T00:00:00.000Z"}