-# $Id: ZOOM.pod,v 1.33 2006-04-11 16:40:08 mike Exp $
+# $Id: ZOOM.pod,v 1.39 2006-11-03 09:36:28 mike Exp $
use strict;
use warnings;
anyway; but knowing that the same code is running is reassuring.)
The ZOOM module provides two enumerations (C<ZOOM::Error> and
-C<ZOOM::Event>), two utility functions C<diag_str()> and C<event()> in
-the C<ZOOM> package itself, and eight classes:
+C<ZOOM::Event>), three utility functions C<diag_str()>, C<event_str()>
+and C<event()> in the C<ZOOM> package itself, and eight classes:
C<ZOOM::Exception>,
C<ZOOM::Options>,
C<ZOOM::Connection>,
C<ZOOM::ScanSet>
and
C<ZOOM::Package>.
-Of these, the Query class is abstract, and has three concrete
+Of these, the Query class is abstract, and has four concrete
subclasses:
C<ZOOM::Query::CQL>,
-C<ZOOM::Query::PQF>
+C<ZOOM::Query::PQF>,
+C<ZOOM::Query::CQL2RPN>
and
-C<ZOOM::Query::CQL2RPN>.
+C<ZOOM::Query::CCL2RPN>.
Finally, it also provides a
C<ZOOM::Query::Log>
module which supplies a useful general-purpose logging facility.
irrespective of whether it is a member of the C<ZOOM::Error>
enumeration or drawn from the BIB-1 diagnostic set.
+=head2 ZOOM::event_str()
+
+ $msg = ZOOM::event_str(ZOOM::Event::RECV_APDU);
+
+Returns a human-readable English-language string corresponding to the
+event code that is its own parameter. This works for any value of the
+C<ZOOM::Event> enumeration.
+
=head2 ZOOM::event()
$connsRef = [ $conn1, $conn2, $conn3 ];
including those that must be set before connecting such as
authentication tokens.
+The server-name string is of the form:
+
=over 4
=item
=item http
-SRW connection using SOAP over HTTP.
+SRU connection over HTTP.
=back
-Support for SRU will follow in the fullness of time.
+If the C<http> scheme is used, the particular SRU flavour to be used
+may be specified by the C<sru> option, which takes the following
+values:
+
+=over 4
+
+=item soap
+
+SRU over SOAP (i.e. what used to be called SRW).
+This is the default.
+
+=item get
+
+"SRU Classic" (i.e. SRU over HTTP GET).
+
+=item post
+
+SRU over HTTP POST.
+
+=back
If an error occurs, an exception is thrown. This may indicate a
networking problem (e.g. the host is not found or unreachable), or a
$options = new ZOOM::Options();
$options->option(implementationName => "my client");
+ $options->option(implementationId => 12345);
$conn = create ZOOM::Connection($options)
+ # or
+ $conn = create ZOOM::Connection(implementationName => "my client",
+ implementationId => 12345);
+
$conn->connect($host, 0);
The usual Connection constructor, C<new()> brings a new object into
existence and forges the connection to the server all in one
operation, which is often what you want. For applications that need
-more control, however, these two method separate the two steps,
+more control, however, these two methods separate the two steps,
allowing additional steps in between such as the setting of options.
C<create()> creates and returns a new Connection object, which is
I<not> connected to any server. It may be passed an options block, of
type C<ZOOM::Options> (see below), into which options may be set
-before or after the creation of the Connection. The connection to the
-server may then be forged by the C<connect()> method, the arguments of
-which are the same as those of the C<new()> constructor.
+before or after the creation of the Connection. Alternatively and
+equivalently, C<create()> may be passed a list of key-value option
+pairs directly. The connection to the server may then be forged by
+the C<connect()> method, the arguments of which are the same as those
+of the C<new()> constructor.
=head4 error_x() / errcode() / errmsg() / addinfo() / diagset()
configuration file is included in the ZOOM-Perl distribution, in the
file C<samples/cql/pqf.properties>
+=item ZOOM::Query::CCL2RPN
+
+Implements CCL by compiling it on the client-side into a Z39.50 Type-1
+(RPN) query, and sending that. Because the compilation is done on the
+client side, a configuration file is required to direct the mapping of
+CCL constructs such as index names and boolean operators into Type-1
+query attributes. An example CCL configuration file is included in
+the ZOOM-Perl distribution, in the file C<samples/ccl/default.bib>
+
+CCL is syntactically very similar to CQL, but much looser. While CQL
+is an entirely precise language in which each possible query has
+rigorously defined semantics, and is thus suitable for transfer as
+part of a protocol, CCL is best deployed as a human-facing UI
+language.
+
=back
See the description of the C<Query> class in the ZOOM Abstract
Connection and be retrieved using C<$conn-E<gt>errcode()> and related
methods.
+ $conn->option(cclfile => "samples/ccl/default.bib");
+ # or
+ $conn->option(cclqual => "ti u=4 s=pw\nab u=62 s=pw");
+ $q = new ZOOM::Query::CCL2RPN('ti=dinosaur', $conn);
+
+For the C<ZOOM::Query::CQL2RPN> subclass, too, the Connection must be
+passed into the constructor, for the same reasons as when client-side
+CQL compilation is used. The C<cclqual> option, if defined, gives a
+CCL qualification specification inline; otherwise, the contents of the
+file named by the C<cclfile> option are used.
+
=head4 sortby()
$q->sortby("1=4 >i 1=21 >s");
C<UNSUPPORTED_PROTOCOL>,
C<UNSUPPORTED_QUERY>,
C<INVALID_QUERY>,
+C<CQL_PARSE>,
+C<CQL_TRANSFORM>,
+C<CCL_CONFIG>,
+C<CCL_PARSE>,
C<CREATE_QUERY>,
C<QUERY_CQL>,
C<QUERY_PQF>,
=back
Here is a very short program (omitting all error-checking!) which
-demonstrates this process. It parallel-searches two servers (or more
+demonstrates this process. It parallel-searches three servers (or more
of you add them the list), displaying the first record in the
result-set of each server as soon as it becomes available.
use ZOOM;
@servers = ('z3950.loc.gov:7090/Voyager',
- 'bagel.indexdata.com:210/gils');
+ 'z3950.indexdata.com:210/gils',
+ 'agricola.nal.usda.gov:7190/Voyager');
for ($i = 0; $i < @servers; $i++) {
$z[$i] = new ZOOM::Connection($servers[$i], 0,
async => 1, # asynchronous mode
projects / ZOOM-Perl-moved-to-github.git / blobdiff