blender-package-manager-addon/__init__.py

bl_info = {
    'name': 'Package Manager',
    'description': 'Testing package management',
    'category': 'System',
    'support': 'TESTING',
}
import bpy

class PackageSettings(bpy.types.PropertyGroup):
    url = bpy.props.StringProperty(name="URL")

# class PackageManager:
#     # For some reason accessing *Property objects stored in this class gives a TypeError:
#     # UILayout.prop(): error with argument 1, "data" -  Function.data expected a AnyType type, not tuple
#     # But accessing them when not stored in a class or dict is fine?
#     settings = bpy.props.PointerProperty(type=PackageSettings)
#     last_response_code = bpy.props.PointerProperty(type=bpy.types.StringProperty)

def register():
    from . import (pkg_ops, pkg_ui)

    bpy.utils.register_class(PackageSettings)
    bpy.types.WindowManager.package_manager_settings = bpy.props.PointerProperty(type=PackageSettings)
    pkg_ops.register()
    pkg_ui.register()

def unregister():
    from . import (pkg_ops, pkg_ui)

    pkg_ops.unregister()
    pkg_ui.unregister();
    bpy.utils.unregister_class(PackageSettings)
    del bpy.types.WindowManager.package_manager_settings