PyObjC Framework InstallerPlugins

Warnings

• breaking PyObjC v12.0 dropped support for Python 3.9. Projects must upgrade to Python 3.10 or newer.
  Fix: Upgrade your Python environment to 3.10 or a later supported version. PyObjC v11.0 similarly dropped Python 3.8 support.
• breaking In PyObjC v11.1, the behavior for Objective-C initializer methods ('init' family) was aligned with `clang`'s Automatic Reference Counting (ARC) documentation. PyObjC now correctly models that these methods steal a reference to `self` and return a new reference, which might change memory management expectations for custom initializers.
  Fix: Review custom initializer methods in Python subclasses of Objective-C objects, especially those interacting with `alloc` and `init` patterns, to ensure correct reference handling under the updated ARC model.
• gotcha PyObjC 10.3 did not support Python 3.13's experimental free-threading (PEP 703). While PyObjC 11.0 introduced *experimental* support, developers should be cautious and test thoroughly when using PyObjC with free-threading Python interpreters, as the bridge's internal C API usage may still have edge cases.
  Fix: Avoid using free-threading Python 3.13+ with PyObjC unless explicitly requiring and thoroughly testing the experimental support. If issues arise, use a standard Python interpreter.
• gotcha There was a temporary change in PyObjC v10.3 where `__init__` could not be used when a class or its superclasses had a user-implemented `__new__`. This was largely reverted in v10.3.1 to support popular projects, but understanding the interaction between `__new__` and Objective-C's two-phase instantiation (`alloc`/`init`) is crucial.
  Fix: If implementing `__new__` in a PyObjC-bridged class, be aware of how it interacts with Objective-C's `alloc` and `init` patterns. For most cases, rely on the behavior re-introduced in 10.3.1, but complex scenarios might require explicit `objc.pyobjc_id` usage.
• breaking PyObjC v10.0 removed the `IMServicePlugIn` bindings entirely, as the framework was deprecated in macOS 10.13 and removed in macOS 14. While this specific package is `InstallerPlugins`, it demonstrates a pattern where bindings for deprecated macOS frameworks are removed in major PyObjC versions without backward compatibility.
  Fix: Always check PyObjC release notes for deprecation or removal of bindings for specific macOS frameworks, especially when upgrading major PyObjC versions or targeting newer macOS versions. Plan to refactor code relying on removed frameworks.

Install

• pip install pyobjc-framework-installerplugins Install stable version

Imports

• InstallerPlugins

  import InstallerPlugins

  Imports the InstallerPlugins framework classes and functions directly.
• NSObject

  from Foundation import NSObject

  Commonly used base class for Objective-C objects, part of the core Foundation framework.
• objc

  import objc

  Provides core PyObjC bridging utilities, decorators, and functions.

Quickstart

This quickstart demonstrates how to import the `InstallerPlugins` framework and define a basic Objective-C compatible class in Python. Actual usage as an Installer Plugin requires a specific project structure, Objective-C class definition patterns, and bundling into a `.bundle` within an installer package, typically managed with tools like `py2app` and proper `InstallerSections.plist` configuration. This example focuses on the Python-side import and class definition.

from Foundation import NSObject
import objc
import InstallerPlugins

class MyCustomInstallerSection(NSObject):
    # The 'alloc().init()' pattern is standard for Objective-C object creation.
    # Python methods often use trailing underscores for Objective-C selector arguments.
    
    # Example: Defining a method that an Installer Plugin might call.
    # In a real plugin, you would override specific methods like 'initWithSection_'.
    @objc.python_method
    def myPluginMethod_(self, installerSection):
        print(f"My custom installer plugin method called by: {installerSection}")
        # You'd typically interact with installerSection here
        return True

# This simple script demonstrates importing the framework and defining a class.
# A real Installer Plugin requires specific project structure and bundling
# (e.g., using py2app) to be loaded by the macOS Installer.app.
if __name__ == '__main__':
    print("InstallerPlugins framework imported successfully.")
    # Instantiate the class (though it won't be 'used' without Installer.app)
    plugin_instance = MyCustomInstallerSection.alloc().init()
    print(f"Instance created: {plugin_instance}")
    # Demonstrate calling a custom method (for illustrative purposes)
    # In practice, the macOS Installer would call specific methods on your plugin.
    # Replace 'None' with a mock InstallerSection object if testing interaction.
    plugin_instance.myPluginMethod_(None)