component.py 文件源码

def adapter(_context, factory, provides=None, for_=None, name=''):

    if for_ is None:
        if len(factory) == 1:
            for_ = adaptedBy(factory[0])

        if for_ is None:
            raise TypeError("No for attribute was provided and can't "
                            "determine what the factory adapts.")

    for_ = tuple(for_)

    if provides is None:
        if len(factory) == 1:
            p = list(implementedBy(factory[0]))
            if len(p) == 1:
                provides = p[0]

        if provides is None:
            raise TypeError("Missing 'provides' attribute")

    if name == '':
        if len(factory) == 1:
            name = getName(factory[0])

    # Generate a single factory from multiple factories:
    factories = factory
    if len(factories) == 1:
        factory = factories[0]
    elif len(factories) < 1:
        raise ComponentConfigurationError("No factory specified")
    elif len(factories) > 1 and len(for_) != 1:
        raise ComponentConfigurationError(
            "Can't use multiple factories and multiple for")
    else:
        factory = _rolledUpFactory(factories)

    _context.action(
        discriminator=('adapter', for_, provides, name),
        callable=handler,
        args=('registerAdapter', factory, for_, provides, name))
    _context.action(
        discriminator=None,
        callable=provide_interface,
        args=('', provides))
    if for_:
        for iface in for_:
            if iface is not None:
                _context.action(
                    discriminator=None,
                    callable=provide_interface,
                    args=('', iface))