##
##
-## $Id: SimpleServer.pm,v 1.35 2007-08-15 13:21:22 mike Exp $
+## $Id: SimpleServer.pm,v 1.42 2007-08-21 16:29:29 mike Exp $
package Net::Z3950::SimpleServer;
@ISA = qw(Exporter AutoLoader DynaLoader);
@EXPORT = qw( );
-$VERSION = '1.06';
+$VERSION = '1.07';
bootstrap Net::Z3950::SimpleServer $VERSION;
if (defined($self->{EXPLAIN})) {
set_explain_handler($self->{EXPLAIN});
}
+ if (defined($self->{DELETE})) {
+ set_delete_handler($self->{DELETE});
+ }
start_server(@args);
}
# Register packages that we will use in translated RPNs
+package Net::Z3950::RPN::Node;
package Net::Z3950::APDU::Query;
+our @ISA = qw(Net::Z3950::RPN::Node);
package Net::Z3950::APDU::OID;
package Net::Z3950::RPN::And;
+our @ISA = qw(Net::Z3950::RPN::Node);
package Net::Z3950::RPN::Or;
+our @ISA = qw(Net::Z3950::RPN::Node);
package Net::Z3950::RPN::AndNot;
+our @ISA = qw(Net::Z3950::RPN::Node);
package Net::Z3950::RPN::Term;
+our @ISA = qw(Net::Z3950::RPN::Node);
package Net::Z3950::RPN::RSID;
+our @ISA = qw(Net::Z3950::RPN::Node);
package Net::Z3950::RPN::Attributes;
package Net::Z3950::RPN::Attribute;
+
+# Utility method for re-rendering Type-1 query back down to PQF
+package Net::Z3950::RPN::Node;
+
+sub toPQF {
+ my $this = shift();
+ my $class = ref $this;
+
+ if ($class eq "Net::Z3950::APDU::Query") {
+ my $res = "";
+ my $set = $this->{attributeSet};
+ $res .= "\@attrset $set " if defined $set;
+ return $res . $this->{query}->toPQF();
+ } elsif ($class eq "Net::Z3950::RPN::Or") {
+ return '@or ' . $this->[0]->toPQF() . ' ' . $this->[1]->toPQF();
+ } elsif ($class eq "Net::Z3950::RPN::And") {
+ return '@and ' . $this->[0]->toPQF() . ' ' . $this->[1]->toPQF();
+ } elsif ($class eq "Net::Z3950::RPN::AndNot") {
+ return '@not ' . $this->[0]->toPQF() . ' ' . $this->[1]->toPQF();
+ } elsif ($class eq "Net::Z3950::RPN::RSID") {
+ return '@set ' . $this->{id};
+ } elsif ($class ne "Net::Z3950::RPN::Term") {
+ die "unknown PQF node-type '$class'";
+ }
+
+ my $res = "";
+ foreach my $attr (@{ $this->{attributes} }) {
+ $res .= "\@attr ";
+ my $set = $attr->{attributeSet};
+ $res .= "$set " if defined $set;
+ $res .= $attr->{attributeType} . "=" . $attr->{attributeValue} . " ";
+ }
+
+ return $res . $this->{term};
+}
+
+
# Must revert to original package for Autoloader's benefit
package Net::Z3950::SimpleServer;
PRESENT => \&my_present_handler,
SCAN => \&my_scan_handler,
FETCH => \&my_fetch_handler,
- EXPLAIN => \&my_explain_handler);
+ EXPLAIN => \&my_explain_handler,
+ DELETE => \&my_delete_handler,
+ SORT => \&my_sort_handler);
In addition, the arguments to the constructor may include GHANDLE, a
global handle which is made available to each invocation of every
=back
-(I guess I should make a superclass C<Net::Z3950::RPN::Node> and make
-all of these subclasses of it. Not done that yet, but will do one day.)
-
=back
=over 4
=item C<attributeValue>
-An integer indicating the value of the attribute - for example, under
+An integer or string indicating the value of the attribute - for example, under
BIB-1, if the attribute type is 1, then value 4 indictates a title
search and 7 indictates an ISBN search; but if the attribute type is
2, then value 4 indicates a ``greater than or equal'' search, and 102
=back
-Note that, at the moment, none of these classes have any methods at
+All of these classes except C<Attributes> and C<Attribute> are
+subclasses of the abstract class C<Net::Z3950::RPN::Node>. That class
+has a single method, C<toPQF()>, which may be used to turn an RPN
+tree, or part of one, back into a textual prefix query.
+
+Note that, apart to C<toPQF()>, none of these classes have any methods at
all: the blessing into classes is largely just a documentation thing
so that, for example, if you do
DATABASES => ["xxx"], ## Reference to a list of data-
## bases to search
TERM => 'start', ## The start term
+ RPN => $obj, ## Reference to a Net::Z3950::RPN::Term
+
NUMBER => xx, ## Number of requested terms
POS => yy, ## Position of starting point
## within returned list
The STEP member contains the requested number of entries in the term-list
between two adjacent entries in the response.
+A better alternative to the TERM member is the the RPN
+member, which is a reference to a Net::Z3950::RPN::Term object
+representing the scan cloause. The structure of that object is the
+same as for Term objects included as part of the RPN tree passed to
+search handlers. This is more useful than the simple TERM because it
+includes attributes (e.g. access points associated with the term),
+which are discarded by the TERM element.
+
=head2 Close handler
The argument hash recieved by the close handler has two elements only:
after this call. If you need to close down a connection to your server
or something similar, this is the place to do it.
+=head2 Delete handler
+
+The argument hash recieved by the delete handler has the following elements:
+
+ $args = {
+ ## Client request:
+ GHANDLE => $obj, ## Global handler specified at creation
+ HANDLE => ref, ## Reference to data structure
+ SETNAME => "id", ## Result set ID
+
+ ## Server response:
+ STATUS => 0 ## Deletion status
+ };
+
+The SETNAME element of the argument hash may or may not be defined.
+If it is, then SETNAME is the name of a result set to be deleted; if
+not, then all result-sets associated with the current session should
+be deleted. In either case, the callback function should report on
+success or failure by setting the STATUS element either to zero, on
+success, or to an integer from 1 to 10, to indicate one of the ten
+possible failure codes described in section 3.2.4.1.4 of the Z39.50
+standard -- see
+http://www.loc.gov/z3950/agency/markup/05.html#Delete-list-statuses1
+
+=head2 Sort handler
+
+The argument hash recieved by the sort handler has the following elements:
+
+ $args = {
+ ## Client request:
+ GHANDLE => $obj, ## Global handler specified at creation
+ HANDLE => ref, ## Reference to data structure
+ INPUT => [ a, b ... ], ## Names of result-sets to sort
+ OUTPUT => "name", ## Name of result-set to sort into
+ SEQUENCE ## Sort specification: see below
+
+ ## Server response:
+ STATUS => 0, ## Success, Partial or Failure
+ ERR_CODE => 0, ## Error code
+ ERR_STR => '', ## Diagnostic message
+
+ };
+
+The SEQUENCE element is a reference to an array, each element of which
+is a hash representing a sort key. Each hash contains the following
+elements:
+
+=over 4
+
+=item RELATION
+
+0 for an ascending sort, 1 for descending, 3 for ascending by
+frequency, or 4 for descending by frequency.
+
+=item CASE
+
+0 for a case-sensitive sort, 1 for case-insensitive
+
+=item MISSING
+
+How to respond if one or more records in the set to be sorted are
+missing the fields indicated in the sort specification. 1 to abort
+the sort, 2 to use a "null value", 3 if a value is provided to use in
+place of the missing data (although in the latter case, the actual
+value to use is currently not made available, so this is useless).
+
+=back
+
+And one or other of the following:
+
+=over 4
+
+=item SORTFIELD
+
+A string indicating the field to be sorted, which the server may
+interpret as it sees fit (presumably by an out-of-band agreement with
+the client).
+
+=item ELEMENTSPEC_TYPE and ELEMENTSPEC_VALUE
+
+I have no idea what this is.
+
+=item ATTRSET and SORT_ATTR
+
+ATTRSET is the attribute set from which the attributes are taken, and
+SORT_ATTR is a reference to an array containing the attributes
+themselves. Each attribute is represented by (are you following this
+carefully?) yet another hash, this one containing the elements
+ATTR_TYPE and ATTR_VALUE: for example, type=1 and value=4 in the BIB-1
+attribute set would indicate access-point 4 which is title, so that a
+sort of title is requested.
+
+=back
+
+Precisely why all of the above is so is not clear, but goes some way
+to explain why, in the Z39.50 world, the developers of the standard
+are not so much worshipped as blamed.
+
+The backend function should set STATUS to 0 on success, 1 for "partial
+success" (don't ask) or 2 on failure, in which case ERR_CODE and
+ERR_STR should be set.
+
=head2 Support for SRU and SRW
Since release 1.0, SimpleServer includes support for serving the SRU