Class dependency

source code

object --+
         |
        dependency

Data descriptor that provides a given dependency looking as an attribute. The depedency is specified as a keyword parameter, whose value can be a default accessor or None. The attribute only tries to fetch the dependency on deman when needed. Example:

    class HttpServer(object):
        connection_port = dependency(http_port = const(80))

    server = HttpServer()
    assert server.connection_port == 80
    with inject(connection_port = const(8000)).everywhere():
        assert server.connection_port == 8000