+sub LimitToParentType {
+ my $self = shift;
+ my $lookup = shift;
+
+ $self->Limit( FIELD => 'LookupType', VALUE => "$lookup", OPERATOR => "STARTSWITH" );
+}
+
+=head2 LimitToObjectId
+
+Takes an ObjectId and limits the collection to CFs applied to said object.
+
+When called multiple times the ObjectId limits are joined with OR.
+
+=cut
+
+sub LimitToObjectId {
+ my $self = shift;
+ my $id = shift;
+ $self->Limit(
+ ALIAS => $self->_OCFAlias,
+ FIELD => 'ObjectId',
+ OPERATOR => '=',
+ VALUE => $id || 0,
+ ENTRYAGGREGATOR => 'OR'
+ );
+}
+
+=head2 LimitToGlobalOrObjectId
+
+Takes list of object IDs and limits collection to custom
+fields that are applied to these objects or globally.
+
+=cut
+
+sub LimitToGlobalOrObjectId {
+ my $self = shift;
+ my $global_only = 1;
+
+
+ foreach my $id (@_) {
+ $self->LimitToObjectId($id);
+ $global_only = 0 if $id;
+ }
+
+ $self->LimitToObjectId(0) unless $global_only;
+}
+
+sub _LimitToOCFs {
+ my $self = shift;
+ my @ids = @_;
+
+ my $ocfs_alias = $self->_OCFAlias( New => 1, Left => 1 );
+ if ( @ids ) {
+ # XXX: we need different EA in join clause, but DBIx::SB
+ # doesn't support them, use IN (X) instead
+ my $dbh = $self->_Handle->dbh;
+ $self->Limit(
+ LEFTJOIN => $ocfs_alias,
+ ALIAS => $ocfs_alias,
+ FIELD => 'ObjectId',
+ OPERATOR => 'IN',
+ QUOTEVALUE => 0,
+ VALUE => "(". join( ',', map $dbh->quote($_), @ids ) .")",
+ );
+ }
+
+ return $ocfs_alias;
+}
+
+=head2 LimitToNotApplied
+
+Takes either list of object ids or nothing. Limits collection
+to custom fields to listed objects or any corespondingly. Use
+zero to mean global.
+
+=cut
+
+sub LimitToNotApplied {
+ my $self = shift;
+ my @ids = @_;
+
+ my $ocfs_alias = $self->_LimitToOCFs(@ids);
+
+ $self->Limit(
+ ENTRYAGGREGATOR => 'AND',
+ ALIAS => $ocfs_alias,
+ FIELD => 'id',
+ OPERATOR => 'IS',
+ VALUE => 'NULL',
+ );
+}
+
+=head2 LimitToApplied
+
+Limits collection to custom fields to listed objects or any corespondingly. Use
+zero to mean global.
+
+=cut
+
+sub LimitToApplied {
+ my $self = shift;
+ my @ids = @_;
+
+ my $ocfs_alias = $self->_LimitToOCFs(@ids);
+
+ $self->Limit(
+ ENTRYAGGREGATOR => 'AND',
+ ALIAS => $ocfs_alias,
+ FIELD => 'id',
+ OPERATOR => 'IS NOT',
+ VALUE => 'NULL',
+ );
+}
+
+=head2 LimitToGlobalOrQueue QUEUEID
+
+DEPRECATED since CFs are applicable not only to tickets these days.
+
+Limits the set of custom fields found to global custom fields or those tied to the queue with ID QUEUEID
+
+=cut
+
+sub LimitToGlobalOrQueue {
+ my $self = shift;
+ my $queue = shift;
+ $self->LimitToGlobalOrObjectId( $queue );
+ $self->LimitToLookupType( 'RT::Queue-RT::Ticket' );
+}
+
+
+=head2 LimitToQueue QUEUEID
+
+DEPRECATED since CFs are applicable not only to tickets these days.
+
+Takes a queue id (numerical) as its only argument. Makes sure that
+Scopes it pulls out apply to this queue (or another that you've selected with
+another call to this method
+
+=cut
+
+sub LimitToQueue {
+ my $self = shift;
+ my $queue = shift;
+
+ $self->Limit (ALIAS => $self->_OCFAlias,
+ ENTRYAGGREGATOR => 'OR',
+ FIELD => 'ObjectId',
+ VALUE => "$queue")
+ if defined $queue;
+ $self->LimitToLookupType( 'RT::Queue-RT::Ticket' );
+}
+
+
+=head2 LimitToGlobal
+
+DEPRECATED since CFs are applicable not only to tickets these days.
+
+Makes sure that Scopes it pulls out apply to all queues
+(or another that you've selected with
+another call to this method or LimitToQueue)
+
+=cut
+
+sub LimitToGlobal {
+ my $self = shift;
+
+ $self->Limit (ALIAS => $self->_OCFAlias,
+ ENTRYAGGREGATOR => 'OR',
+ FIELD => 'ObjectId',
+ VALUE => 0);
+ $self->LimitToLookupType( 'RT::Queue-RT::Ticket' );
+}
+
+
+=head2 ApplySortOrder
+
+Sort custom fields according to thier order application to objects. It's
+expected that collection contains only records of one
+L<RT::CustomField/LookupType> and applied to one object or globally
+(L</LimitToGlobalOrObjectId>), otherwise sorting makes no sense.
+
+=cut
+
+sub ApplySortOrder {