API Documentation

class ZCatalog

ZCatalog object

A ZCatalog contains arbitrary index like references to Zope objects. ZCatalog's can index either Field values of object, Text values, or KeyWord values:

ZCatalogs have three types of indexes:

Text: Text indexes index textual content. The index can be used to search for objects containing certain words.
Field: Field indexes index atomic values. The index can be used to search for objects that have certain properties.
Keyword: Keyword indexes index sequences of values. The index can be used to search for objects that match one or more of the search terms.

The ZCatalog can maintain a table of extra data about cataloged objects. This information can be used on search result pages to show information about a search result.

The meta-data table schema is used to build the schema for ZCatalog Result objects. The objects have the same attributes as the column of the meta-data table.

ZCatalog does not store references to the objects themselves, but rather to a unique identifier that defines how to get to the object. In Zope, this unique identifier is the object's relative path to the ZCatalog (since two Zope objects cannot have the same URL, this is an excellent unique qualifier in Zope).

Product Constructor

manage_addZCatalog(id, title, vocab_id=None):

Add a ZCatalog object.

vocab_id is the name of a Vocabulary object this catalog should use. A value of None will cause the Catalog to create its own private vocabulary.

Methods

schema():

Returns a sequence of names that correspond to columns in the meta-data table.

call(REQUEST=None, **kw):

Search the catalog, the same way as searchResults.

uncatalog_object(uid):

Uncatalogs the object with the unique identifier uid.

getobject(rid, REQUEST=None):

Return a cataloged object given a 'datarecordid_'

indexes():

Returns a sequence of names that correspond to indexes.

getpath(rid):

Return the path to a cataloged object given a 'datarecordid_'

index_objects():

Returns a sequence of actual index objects.

refreshCatalog(self, clear=0):

Re-index and re-read meta-data for all objects in the Catalog. If the clear flag is set, empty the catalog and re-fill it, otherwise try to write minimal changes.

searchResults(REQUEST=None, **kw):

Search the catalog. Search terms can be passed in the REQUEST or as keyword arguments.

Search queries consist of a mapping of index names to search parameters. You can either pass a mapping to searchResults as the variable REQUEST or you can use index names and search parameters as keyword arguments to the method, in other words:

  searchResults(title='Elvis Exposed',
                author='The Great Elvonso')

is the same as:

  searchResults({'title' : 'Elvis Exposed',
                 'author : 'The Great Elvonso'})

In these examples, title and author are indexes. This query will return any objects that have the title Elvis Exposed AND also are authored by The Great Elvonso. Terms that are passed as keys and values in a searchResults() call are implicitly ANDed together. To OR two search results, call searchResults() twice and add concatenate the results like this:

  results = ( searchResults(title='Elvis Exposed') +
              searchResults(author='The Great Elvonso') )

This will return all objects that have the specified title OR the specified author.

There are some special index names you can pass to change the behavior of the search query:

sort_on: This parameters specifies which index to sort the results on.
sort_order: You can specify reverse or descending. Default behavior is to sort ascending.

There are some rules to consider when querying this method:

an empty query mapping (or a bogus REQUEST) returns all items in the catalog.
results from a query involving only field/keyword indexes, e.g. {'id':'foo'} and no sort_on will be returned unsorted.
results from a complex query involving a field/keyword index and a text index, e.g. {'id':foo,'PrincipiaSearchSource':'bar'} and no sort_on will be returned unsorted.
results from a simple text index query e.g.{'PrincipiaSearchSource':'foo'} will be returned sorted in descending order by score. A text index cannot beused as a sort_on parameter, and attempting to do so will raise an error.

Depending on the type of index you are querying, you may be able to provide more advanced search parameters that can specify range searches or wildcards. These features are documented in The Zope Book.

uniqueValuesFor(name):

returns the unique values for a given FieldIndex named name.

catalog_object(obj, uid):

Catalogs the object obj with the unique identifier uid.