Bio::SeqFeature::AnnotationAdaptor - integrates SeqFeatureIs annotation
use Bio::SeqFeature::Generic; use Bio::SeqFeature::AnnotationAdaptor; # obtain a SeqFeatureI implementing object somehow my $feat = Bio::SeqFeature::Generic->new(-start => 10, -end => 20); # add tag/value annotation $feat->add_tag_value("mytag", "value of tag mytag"); $feat->add_tag_value("mytag", "another value of tag mytag"); # Bio::SeqFeature::Generic also provides annotation(), which returns a # Bio::AnnotationCollectionI compliant object $feat->annotation->add_Annotation("dbxref", $dblink); # to integrate tag/value annotation with AnnotationCollectionI # annotation, use this adaptor, which also implements # Bio::AnnotationCollectionI my $anncoll = Bio::SeqFeature::AnnotationAdaptor->new(-feature => $feat); # this will now return tag/value pairs as # Bio::Annotation::SimpleValue objects my @anns = $anncoll->get_Annotations("mytag"); # other added before annotation is available too my @dblinks = $anncoll->get_Annotations("dbxref"); # also supports transparent adding of tag/value pairs in # Bio::AnnotationI flavor my $tagval = Bio::Annotation::SimpleValue->new(-value => "some value", -tagname => "some tag"); $anncoll->add_Annotation($tagval); # this is now also available from the feature's tag/value system my @vals = $feat->each_tag_value("some tag");
Bio::SeqFeatureI defines light-weight annotation of features through tag/value pairs. Conversely, Bio::AnnotationCollectionI together with Bio::AnnotationI defines an annotation bag, which is better typed, but more heavy-weight because it contains every single piece of annotation as objects. The frequently used base implementation of Bio::SeqFeatureI, Bio::SeqFeature::Generic, defines an additional slot for AnnotationCollectionI-compliant annotation.
This adaptor provides a Bio::AnnotationCollectionI compliant, unified, and integrated view on the annotation of Bio::SeqFeatureI objects, including tag/value pairs, and annotation through the annotation() method, if the object supports it. Code using this adaptor does not need to worry about the different ways of possibly annotating a SeqFeatureI object, but can instead assume that it strictly follows the AnnotationCollectionI scheme. The price to pay is that retrieving and adding annotation will always use objects instead of light-weight tag/value pairs.
In other words, this adaptor allows us to keep the best of both worlds. If you create tens of thousands of feature objects, and your only annotation is tag/value pairs, you are best off using the features' native tag/value system. If you create a smaller number of features, but with rich and typed annotation mixed with tag/value pairs, this adaptor may be for you. Since its implementation is by double-composition, you only need to create one instance of the adaptor. In order to transparently annotate a feature object, set the feature using the feature() method. Every annotation you add will be added to the feature object, and hence will not be lost when you set feature() to the next object.
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The rest of the documentation details each of the object methods. Internal methods are usually preceded with a _
Title : new Usage : my $obj = Bio::SeqFeature::AnnotationAdaptor->new(); Function: Builds a new Bio::SeqFeature::AnnotationAdaptor object Returns : an instance of Bio::SeqFeature::AnnotationAdaptor Args : Named parameters -feature the Bio::SeqFeatureI implementing object to adapt (mandatory to be passed here, or set via feature() before calling other methods) -annotation the Bio::AnnotationCollectionI implementing object for storing richer annotation (this will default to the $feature->annotation() if it supports it) -tagvalue_factory the object factory to use for creating tag/value pair representing objects
Title : feature Usage : $obj->feature($newval) Function: Get/set the feature that this object adapts to an AnnotationCollectionI. Example : Returns : value of feature (a Bio::SeqFeatureI compliant object) Args : new value (a Bio::SeqFeatureI compliant object, optional)
Title : annotation Usage : $obj->annotation($newval) Function: Get/set the AnnotationCollectionI implementing object used by this adaptor to store additional annotation that cannot be stored by the SeqFeatureI itself. If requested before having been set, the value will default to the annotation object of the feature if it has one. Example : Returns : value of annotation (a Bio::AnnotationCollectionI compliant object) Args : new value (a Bio::AnnotationCollectionI compliant object, optional)
Title : get_all_annotation_keys Usage : $ac->get_all_annotation_keys() Function: gives back a list of annotation keys, which are simple text strings Returns : list of strings Args : none
Title : get_Annotations Usage : my @annotations = $collection->get_Annotations('key') Function: Retrieves all the Bio::AnnotationI objects for a specific key Returns : list of Bio::AnnotationI - empty if no objects stored for a key Args : string which is key for annotations
Title : get_num_of_annotations Usage : my $count = $collection->get_num_of_annotations() Function: Returns the count of all annotations stored in this collection Returns : integer Args : none
Title : add_Annotation Usage : $self->add_Annotation('reference',$object); $self->add_Annotation($object,'Bio::MyInterface::DiseaseI'); $self->add_Annotation($object); $self->add_Annotation('disease',$object,'Bio::MyInterface::DiseaseI'); Function: Adds an annotation for a specific key. If the key is omitted, the object to be added must provide a value via its tagname(). If the archetype is provided, this and future objects added under that tag have to comply with the archetype and will be rejected otherwise. This implementation will add all Bio::Annotation::SimpleValue objects to the adapted features as tag/value pairs. Caveat: this may potentially result in information loss if a derived object is supplied. Returns : none Args : annotation key ('disease', 'dblink', ...) object to store (must be Bio::AnnotationI compliant) [optional] object archetype to map future storage of object of these types to
Title : remove_Annotations Usage : Function: Remove the annotations for the specified key from this collection. If the key happens to be a tag, then the tag is removed from the feature. Example : Returns : an array Bio::AnnotationI compliant objects which were stored under the given key(s) Args : the key(s) (tag name(s), one or more strings) for which to remove annotations (optional; if none given, flushes all annotations)
Title : tagvalue_object_factory Usage : $obj->tagval_object_factory($newval) Function: Get/set the object factory to use for creating objects that represent tag/value pairs (e.g., Bio::Annotation::SimpleValue). The object to be created is expected to follow Bio::Annotation::SimpleValue in terms of supported arguments at creation time, and the methods. Example : Returns : A Bio::Factory::ObjectFactoryI compliant object Args : new value (a Bio::Factory::ObjectFactoryI compliant object, optional)