c.l.c.d.DecoratedResultSet(object) : class documentation

Part of canonical.launchpad.components.decoratedresultset View In Hierarchy

A decorated Storm ResultSet for 'Magic' (presenter) classes.

Because DistroSeriesBinaryPackage doesn't actually exist in the database, the DistroSeries.searchPackages method uses the DistroSeriesPackageCache object to search for packages within a DistroSeries.

Nonetheless, the users of the searchPackages method (such as the DistroSeriesView) expect a result set of DSBPs. Rather than executing the query prematurely and doing a list comprehension on the complete result set (which could be very large) to convert all the results (even though batching may mean only a window of 10 results is required), this adapted result set converts the results only when they are needed.

This behaviour is required for other classes as well (Distribution, DistroArchSeries), hence a generalised solution.

Method	__init__
Method	decorate_or_none	Decorate a result or return None if the result is itself None
Method	copy	See `IResultSet`.
Method	config	See `IResultSet`.
Method	__iter__	See `IResultSet`.
Method	__getitem__	See `IResultSet`.
Method	any	See `IResultSet`.
Method	first	See `IResultSet`.
Method	last	See `IResultSet`.
Method	one	See `IResultSet`.
Method	order_by	See `IResultSet`.

def __init__(self, result_set, result_decorator=None, pre_iter_hook=None, slice_info=False):

Parameters	result_set	The original result set to be decorated.
	result_decorator	The method with which individual results will be passed through before being returned.
	pre_iter_hook	The method to be called (with the 'result_set') immediately before iteration starts.
	slice_info	If True pass information about the slice parameters to the result_decorator and pre_iter_hook. any() and similar methods will cause None to be supplied.

def decorate_or_none(self, result, row_index=None):

Decorate a result or return None if the result is itself None

def copy(self, *args, **kwargs):

See IResultSet.

Returns The decorated version of the returned result set.

def config(self, *args, **kwargs):

See IResultSet.

Returns The decorated result set.after updating the config.

def __iter__(self, *args, **kwargs):

See IResultSet.

Yield a decorated version of the returned value.

def __getitem__(self, *args, **kwargs):

See IResultSet.