Development information
An overview of the database schema and data layer API
Annotations
The AnnotationSetData [API]
class holds all annotations for a single item. An item must implement the
AnnotatableData [API]
interface which defines the annotationSet property for that item.
Each annotation set can contain annotations that are directly associated
with the item (primary annotations). These annotations are available in the
annotations property. This property is a map with an AnnotationType
as the key. Thus an annotation set can contain only one annotation of
a specific annotation type.
The annotation set can also contain inherited annotations and annotation sets.
These are found in the inherited and inheritedSets
properties. Logically the inherited annotations should come from one of the
parent items, but this is more or less impossible to check. There are no
restrictions on the annotation types of the inherited annotations.
The AnnotationData [API]
class is the placeholder for an annotation. It must have a type and belong to an
annotation set. The actual annotation values are stored as ParameterValueData
objects. Note that it is possible for an annotation to have multiple values.
The AnnotationTypeData [API]
class defines the various annotations. It must have a valueType property which cannot
be changed. The value of this property controls which ParameterValueData subclass
is used to store annotation values, ie. IntegerParameterValueData,
StringParameterValueData. The multiplicity property
holds the maximum allowed number of values for an annotation, or 0 if an unlimited
number is allowed.
The itemTypes collection holds the codes for the types of items
the annotation type can be used on. This is checked when new annotations are created
but already existing annotations are not affected if the collection is modified.
Annotation types with the protocolParameter flag set are treated a
bit differently. They will not show up as annotations to items with a type
found in the itemTypes collection. A protocol parameter should
be attached to a Protocol. Then, when an item is using that
protocol it becomes possible to add annotation values for the annotation types
specified as protocol parameters. It doesn't matter if the item's type is found
in the itemTypes collection or not.
The options collection is used to store additional options
required by some of the value types, for example a max string length for
string annotations or the max and min allowed value for integer annotations.
The enumeration property is a boolean flag indicating if the allowed
values are predefined as an enumeration. In that case those values are found
in the enumerationValues property. The actual subclass is determined by
the valueType property.
Most of the other properties are hints to client applications how to render the input field for the annotation.
The AnnotationTypeCategory [API]
class defined categories that are used to group annotation types that are
related to each other. This information is mainly useful for client applications
when displaying forms for annotating items, that wish to provide a clearer interface
when there are many (say 50+) annotations type for an item.
An annotation type can belong to more than one category.