BTree folder with the option to keep an ordering in the items
This btree folder class implements the OrderSupport interface from the core Zope2.7+ distribution. It is a subclass of the BTreeFolder2 product from Shane Hathaway. The BTreeFolder2 product needs to be installed alongside this product.
This folder has the advantages of a normal BTreefolder. Object listing and access to single objects, does not load unused objects into memory.
With the ordering support one can use this folder as a base class for other more application oriented containers.
Every OBTreeFolder has the property insertmodus which defines where in the ordering new objects should be added. Default is at the beginning of the ordered list.
This product is licensed under the GPL, read LICENSE.GPL for more info.
Thanks to Helge Tesdal for a nice optimization hint.