package DBIx::SearchBuilder::Union; use strict; use warnings; # WARNING --- This is still development code. It is experimental. our $VERSION = '0'; # This could inherit from DBIx::SearchBuilder, but there are _a lot_ # of things in DBIx::SearchBuilder that we don't want, like Limit and # stuff. It probably makes sense to (eventually) split out # DBIx::SearchBuilder::Collection to contain all the iterator logic. # This could inherit from that. =head1 NAME DBIx::SearchBuilder::Union - Deal with multiple SearchBuilder result sets as one =head1 SYNOPSIS use DBIx::SearchBuilder::Union; my $U = new DBIx::SearchBuilder::Union; $U->add( $tickets1 ); $U->add( $tickets2 ); $U->GotoFirstItem; while (my $z = $U->Next) { printf "%5d %30.30s\n", $z->Id, $z->Subject; } =head1 WARNING This module is still experimental. =head1 DESCRIPTION Implements a subset of the DBIx::SearchBuilder collection methods, but enough to do iteration over a bunch of results. Useful for displaying the results of two unrelated searches (for the same kind of objects) in a single list. =head1 METHODS =head2 new Create a new DBIx::SearchBuilder::Union object. No arguments. =cut sub new { bless { data => [], curp => 0, # current offset in data item => 0, # number of indiv items from First count => undef, }, shift; } =head2 add $sb Add a searchbuilder result (collection) to the Union object. It must be the same type as the first object added. =cut sub add { my $self = shift; my $newobj = shift; unless ( @{$self->{data}} == 0 || ref($newobj) eq ref($self->{data}[0]) ) { die "All elements of a DBIx::SearchBuilder::Union must be of the same type. Looking for a " . ref($self->{data}[0]) ."."; } $self->{count} = undef; push @{$self->{data}}, $newobj; } =head2 First Return the very first element of the Union (which is the first element of the first Collection). Also reset the current pointer to that element. =cut sub First { my $self = shift; die "No elements in DBIx::SearchBuilder::Union" unless @{$self->{data}}; $self->{curp} = 0; $self->{item} = 0; $self->{data}[0]->First; } =head2 Next Return the next element in the Union. =cut sub Next { my $self=shift; return undef unless defined $self->{data}[ $self->{curp} ]; my $cur = $self->{data}[ $self->{curp} ]; if ( $cur->_ItemsCounter == $cur->Count ) { # move to the next element $self->{curp}++; return undef unless defined $self->{data}[ $self->{curp} ]; $cur = $self->{data}[ $self->{curp} ]; $self->{data}[ $self->{curp} ]->GotoFirstItem; } $self->{item}++; $cur->Next; } =head2 Last Returns the last item =cut sub Last { die "Last doesn't work right now"; my $self = shift; $self->GotoItem( ( $self->Count ) - 1 ); return ( $self->Next ); } =head2 Count Returns the total number of elements in the Union'ed Collection =cut sub Count { my $self = shift; my $sum = 0; # cache the results return $self->{count} if defined $self->{count}; $sum += $_->Count for (@{$self->{data}}); $self->{count} = $sum; return $sum; } =head2 GotoFirstItem Starts the recordset counter over from the first item. the next time you call Next, you'll get the first item returned by the database, as if you'd just started iterating through the result set. =cut sub GotoFirstItem { my $self = shift; $self->GotoItem(0); } sub GotoItem { my $self = shift; my $item = shift; die "We currently only support going to the First item" unless $item == 0; $self->{curp} = 0; $self->{item} = 0; $self->{data}[0]->GotoItem(0); return $item; } =head2 IsLast Returns true if the current row is the last record in the set. =cut sub IsLast { my $self = shift; $self->{item} == $self->Count ? 1 : undef; } =head2 ItemsArrayRef Return a refernece to an array containing all objects found by this search. Will destroy any positional state. =cut sub ItemsArrayRef { my $self = shift; return [] unless $self->Count; $self->GotoFirstItem(); my @ret; while( my $r = $self->Next ) { push @ret, $r; } return \@ret; } =head1 AUTHOR Copyright (c) 2004 Robert Spier All rights reserved. This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. =head1 SEE ALSO DBIx::SearchBuilder =cut 1; __END__