/ 
bioperl-1.5.2_004-RCb
/ Bio::AnnotationI

NAME

Bio::AnnotationI - Annotation interface

SYNOPSIS

# generally you get AnnotationI's from AnnotationCollectionI's

 foreach $key ( $ac->get_all_annotation_keys() ) {
     @values = $ac->get_Annotations($key);
     foreach $value ( @values ) {
        # value is an Bio::AnnotationI, and defines a "as_text" method
        print "Annotation ",$key," stringified value ",$value->as_text,"\n";
        # you can also use a generic hash_tree method for getting
        # stuff out say into XML format
        $hash_tree = $value->hash_tree();
     }
 }

DESCRIPTION

Interface all annotations must support. There are two things that each annotation has to support.

$annotation->as_text()

Annotations have to support an "as_text" method. This should be a single text string, without newlines representing the annotation, mainly for human readability. It is not aimed at being able to store/represent the annotation.

The second method allows annotations to at least attempt to represent themselves as pure data for storage/display/whatever. The method hash_tree

$hash = $annotation->hash_tree();

should return an anonymous hash with "XML-like" formatting. The formatting is as follows.

(1) For each key in the hash, if the value is a reference'd array -

    (2) For each element of the array if the value is a object -
        Assume the object has the method "hash_tree";
    (3) else if the value is a referene to a hash
        Recurse again from point (1)
    (4) else
        Assumme the value is a scalar, and handle it directly as text

 (5) else (if not an array) apply rules 2,3 and 4 to value

The XML path in tags is represented by the keys taken in the hashes. When arrays are encountered they are all present in the path level of this tag

This is a pretty "natural" representation of an object tree in an XML style, without forcing everything to inheriet off some super-generic interface for representing things in the hash.

FEEDBACK

Mailing Lists

User feedback is an integral part of the evolution of this and other Bioperl modules. Send your comments and suggestions preferably to one of the Bioperl mailing lists. Your participation is much appreciated.

bioperl-l@bioperl.org

Reporting Bugs

Report bugs to the Bioperl bug tracking system to help us keep track the bugs and their resolution. Bug reports can be submitted via the web:

http://bugzilla.open-bio.org/

AUTHOR - Ewan Birney

Email birney@ebi.ac.uk

APPENDIX

The rest of the documentation details each of the object methods. Internal methods are usually preceded with a _

as_text

Title   : as_text
Usage   :
Function: single text string, without newlines representing the
          annotation, mainly for human readability. It is not aimed
          at being able to store/represent the annotation.
Example :
Returns : a string
Args    : none

hash_tree

Title   : hash_tree
Usage   :
Function: should return an anonymous hash with "XML-like" formatting
Example :
Returns : a hash reference
Args    : none

tagname

Title   : tagname
Usage   : $obj->tagname($newval)
Function: Get/set the tagname for this annotation value.

          Setting this is optional. If set, it obviates the need to
          provide a tag to Bio::AnnotationCollectionI when adding
          this object. When obtaining an AnnotationI object from the
          collection, the collection will set the value to the tag
          under which it was stored unless the object has a tag
          stored already.

Example :
Returns : value of tagname (a scalar)
Args    : new value (a scalar, optional)