DAS::GUS - DAS-style accession to a gus database


        # Open up a feature database
        $db = DAS::GUS->new(
                        -dsn  => 'dbi:Oracle:sid=GUSDEV;host=localhost;port=1521',
                                                -user => 'user',
                                                -pass => 'pass', );
        @segments = $db->segment ( -name  => 'AAEE01000001',
                                                           -start => 1,
                                                           -end   => 1000000 );
        # segments are Bio::Das::SegmentI - compliant objects
        # fetch a list of features
        @features = $db->features( -type=>['type1', 'type2', 'type3'] );

        # invoke a callback over features
        $db->features( -type=>['type1', 'type2', 'type3'], 
                                   -callback => sub { ... }

        # get all featur types
        @types = $db->types

        # count types
        %types = $db->types( -enumerate=>1 );

        @feature = $db->get_feature_by_name( $class=>$name );
        @feature = $db->get_feature_by_target( $target_name );
        @feature = $db->get_feature_by_attribute( $att1=>$value1, 
                                                                                          $att2=>$value2 );
        $feature = $db->get_feature_by_id( $id );

        $error = $db->error;


Name: Haiming Wang Email:


  Title         : new
  Usage         : $db = DAS::GUS->new (
                                                -dsn  => 'dbi:Oracle:sid=GUSDEV;host=localhost;port=1521',
                                                -user => 'user',
                                                -pass => 'pass', );
  Function      : Open up a Bio::DB::DasI interface to a GUS database
  Returns       : a new DAS::GUS object


  Title         : dbh
  Usage         : $obj->dbh($newval)
  Function  : get a database handle
  Returns       : value of dbh (a scalar)
  Args          : on set, new value (a scalar or undef, optional)


  Title         : parser
  Usage         : $obj->parser($parserObj)
  Function  : get a sql parser object
  Returns       : a sql parser object
  Args          : 


  Title         : segment
  Usage         : $db->segment(@args)
  Function      : create a segment object
  Returns       : segment object(s)
  Args          : see below

This method generates a Bio::Das::SegmentI object (see Bio::Das::SegmentII). The segment can be used to find overlapping features and the raw sequence.

When making the segment() call, you specify the ID of a sequence landmark (e.g. an accession number, a clone or contig), and a positional range relative to the landmark. If no range is specified, then the entire region spanned by the landmark is used to generate the segment.

Arguments are -option=>value pairs as follows:

  -name         ID of the landmark sequence.

  -class        A namespace qualifier. It is not necessary for the 
                    database to honor namespace qualifiers, but if it does, 
                        this is where the qualifier is indicated.

  -version      Version number of the landmark. It is not necessary 
                        for the database to honor version, but if it does, 
                        this is where the version is indicated.

  -start        Start of the segment relative to landmark. Positions 
                        follow standard 1-based sequence rules.  If not 
                        specified, defaults to the beginning of the landmark.
  -end          End of the segment relative to the landmark. If not 
                    specified, defaults to the end of the landmark.

  -atts     Attribute of reference sequence

The return value is a list of Bio::Das::SegmentI objects. If the method is called in a scalar context and there are no more than one segments that satisfy the request, then it is allowed to return the segment. Otherwise, the method must throw a "multiple segment exception".


  Title         : fetures
  Usage         : $db->features(@args)
  Function      : get all features, possibly filtered by type
  Returns       : a list of DAS::GUS::Segment::Feature objects
  Args          : see below
  Status        : public

This routine will retrieve features in the database regardless of position. It can be used to return all features, or a subset based on their method and source.

Arguments are -option=>value pairs as follows:

  -type         List of feature types to return. Argument is an array of i
                        reference containing strings of the format "method:source"

  -callback     A callback to invoke on each feature. The subroutine will
                        be passed each Bio::SeqFeatureI object in turn.

  -attributes   A has reference containing attributes to match.

  -iterator Whether to return an iterator across the features

Types are indicated using the nomenclature "method:source". Either of these fields can be omitted, in which case a wildcard is used for the missing field. Type names without the colon (e.g. "exon") are interpreted as the method name and a source wild card. Regular expression are allowed in either field, as in: "similarity:BLAST.*".

The -attributes argument is a hashref containing one or more attributes to match against:

  -attributes => { Gene => 'abc-1',
                                   Note => 'confirmed' }

Attribute matching is simple exact string match, and multiple attributes are ANDed together.

If one provides a callback, it will be invoked on each feature in turn. If the callback returns a false value, iteration will be interrupted. When a callback is provided, the method returns undef.


        Title   : get_feature_by_name
        Usage   : $db->get_feature_by_name($class => $name)
        Function: fetch features by their name
        Returns : a list of DAS::GUS::Segment::Feature objects
        Args    : the class and the name of the desired feature
        Status  : public

        Note    : You need to modify _feature_get() in currently. 
          Find "return unless @segments;" and change it to "return @segments;"    
          Debug it later. Also see multiple_choice() in gbrowse cgi script for
          getting features\'s attributes