source: products/quintagroup.catalogupdater/trunk/README.txt @ 1800

Introduction
============

This package is intended for extending ZCatalog API with possiblity to
update selected columns only. This package registers 'catalog_updater'
utility for that.

To simplify usage of the utility, it extends GenericSetup's ZCatalog
XMLAdapter handler, which allows to *update* attribute usage in *column*
tag of *catalog.xml* file.

So, when you add a new column to the catalog, you add catalog.xml file
in some profile with following part:

...
<column value="new_column" />
...

This adds *new_column* metadata to the portal_catalog, BUT, this
metadata will be empty untill you rebuild the catalog. To automate
this step you can add 'update="True"' attribute to the tag. And this
will lead to column update after adding. Thus, result usage should look
like this:

...
<column value="new_column" update="True" />
...

Also supports subtransactions, based on threshold property of ZCatalog.