Net::Z3950::APDU - Read-only objects representing decoded Z39.50 APDUs
You probably shouldn't be reading this!
package Net::Z3950::APDU::SomeSpecificSortOfAPDU;
use Net::Z3950::APDU;
@ISA = qw(Net::Z3950::APDU);
@FIELDS = qw(names of APDU fields);
This class provides a trivial base for the various read-only APDUs
implemented as a part of the Net::Z3950 module. Its role is simply to
supply named methods providing read-only access to the same-named
fields. The set of fields is specified by the derived class's
package-global @FIELDS array.
You don't need to understand or use this class in order to use the Net::Z3950 module. It's purely an implementation detail. In fact, I probably should never even have written this documentation. Forget I said anything. Go and read the next section.
The following classes are all trivial derivations of Net::Z3950::APDU,
and represent specific types of APDU. Each such class is
characterised by the set of data-access methods it supplies: these are
listed below.
Each method takes no arguments, and returns the information implied by
its name. See the relevant sections of the Z39.50 Standard for
information on the interpretation of this information - for example,
section 3.2.1 (Initialization Facility) describes the elements of the
Net::Z3950::APDU::InitResponse class.
Actually, you don't need to understand or use any of these classes either: they're used internally in the implementation, so this documentation is provided as a service to those who will further develop this module in the future.
referenceId()
preferredMessageSize()
maximumRecordSize()
result()
implementationId()
implementationName()
implementationVersion()
referenceId()
resultCount()
numberOfRecordsReturned()
nextResultSetPosition()
searchStatus()
resultSetStatus()
presentStatus()
records()
additionalSearchInfo()
referenceId()
stepSize()
scanStatus()
numberOfEntriesReturned()
positionOfTerm()
entries()
diag()
The diag() method should be consulted when scanStatus() returns
6, indicating failure; otherwise, entries() may be consulted.
referenceId()
numberOfRecordsReturned()
nextResultSetPosition()
presentStatus()
records()
referenceId()
deleteOperationStatus()
(We don't bother to decode the rest of this APDU at the moment, since
I bet everyone calls Net::Z3950::ResultSet::delete() in void
context. If anyone wants more information out of it, we can wire it
through.)
referenceId()
closeReason()
diagnosticInformation()
In addition, this class provides a method of no arguments,
as_text(), which returns a human-readable string describing the
reason for the close.
No methods - just treat as a reference to an array of
Net::Z3950::APDU::NamePlusRecord
databaseName()
which()
databaseRecord()
surrogateDiagnostic()
startingFragment()
intermediateFragment()
finalFragment()
Only one of the last five methods will return anything - you can find
out which one by inspecting the return value of the which() method,
which always takes one of the following values:
When which() is Net::Z3950::NamePlusRecord::DatabaseRecord, the
object returned from the databaseRecord() method will be a decoded
Z39.50 EXTERNAL. Its type may be any of the following (and may be
tested using $rec->isa('Net::Z3950::Record::Whatever') if necessary.)
### others, not yet supported
No methods - just treat as an opaque chunk of data.
tagType()
tagValue()
tagOccurrence()
content()
which()
numeric()
string()
oid()
subtree()
Only one of the last four methods will return anything - you can find
out which one by inspecting the return value of the which() method,
which always takes one of the following values:
No methods - just treat as a reference to an array of objects, where
each object is either an MARC holdings record (of type
Net::Z3950::Record::USMARC or similar) or a
Net::Z3950::APDU::HoldingsAndCirc
typeOfRecord()
encodingLevel()
format()
receiptAcqStatus()
generalRetention()
completeness()
dateOfReport()
nucCode()
localLocation()
shelvingLocation()
callNumber()
shelvingData()
copyNumber()
publicNote()
reproductionNote()
termsUseRepro()
enumAndChron()
volumes()
circulationData()
All but the last two of these have string values, although not
necessarily human-readable strings. volumes() returns a
Net::Z3950::APDU::Volumes object (note the plural in the
type-name), and circulationData() a
Net::Z3950::APDU::CirculationData.
No methods - just treat as a reference to an array of
Net::Z3950::APDU::Volume
objects.
enumeration()
chronology()
enumAndChron()
No methods - just treat as a reference to an array of
Net::Z3950::APDU::CircRecord
objects.
availableNow()
availablityDate()
availableThru()
restrictions()
itemId()
renewable()
onHold()
enumAndChron()
midspine()
temporaryLocation()
No methods - just treat as a reference to an array of object
references. The objects will typically be of class
Net::Z3950::APDU::DefaultDiagFormat, but careful callers will check
this, since any kind of EXTERNAL may be provided instead.
diagnosticSetId()
condition()
addinfo()
No longer exists.
Previously this class had no methods - calling code just treated it
as a reference to an array of integers. However, since the only thing
anyone (including Net::Z3950::Record::GRS1::render())
ever did with it was smush it up into a string with
join('.', @$oidRef)
we now just return the dot-separated OID string not blessed into any class (because scalars can't be blessed - only references to scalars, and we don't want the extra useless level of indirection).
No methods - just treat as a reference to an array of
Net::Z3950::APDU::Entry
termInfo()
surrogateDiagnostic()
Usually, termInfo() returns a scanned term. When it returns an
undefined value, consult <surrogateDiagnostic()> to find out why.
term()
globalOccurrences()
### Lots more to come here, including displayTerm
general()
numeric()
characterString()
oid()
dateTime()
external()
integerAndUnit()
null()
At present only ``general'' terms are supported. The value of such a term may be obtained by calling <general()>. Terms of other types can not be obtained.
No methods - just treat as a reference to an array of
Net::Z3950::APDU::OtherInformationUnit
which()
characterInfo()
binaryInfo()
externallyDefinedInfo
oid()
At present only ``externallyDefinedInfo'' units are supported.
No methods - just treat as a reference to an array of
Net::Z3950::APDU::SearchInfoReport_s
fullQuery()
subqueryExpression()
subqueryCount()
which()
term()
query()
At present only ``term'' query expressions are supported.
queryTerm()
Mike Taylor <mike@indexdata.com>
First version Saturday 27th May 2000.