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- Name
- required item. Identifies the asset within the scope.
Names can be prefixed with a namespace prefix. If the name is not
prefixed, it belongs to the model default
namespace. The namespace is relevant when models are merged.
The combination of namespace and asset name must be globally unique.
- Image
- optional. An image in the top right corner may be used for asset
illustration.
- Label
- optional. The display name for asset instances. If omitted, the
display name of instances is the asset name. Several names are
possible within one label which then act as aliases. Labels are not necessarily
unique but belong to the asset's namespace.
A
label with a gray background denotes an abstract asset, i.e. an asset that cannot have
instances.
- Name formulas may be used as a display
label.
- Scope
- defines a limited context for assets. Multiple scopes are allowed.
All asset definitions are only valid within the specified scope(s). A
typical example for using scopes is versioning. If no scope is
supplied, the asset is valid in all scopes defined for the model.
- Key
- an arbitrary number of primary keys (usually one) that identify
asset instances uniquely. A key can be decorated with a name which
must be unique within the context of the asset.
- Property
- Each property describes a certain aspect of an asset. For example,
an asset Person would have properties such as Name, Height, Weight,
Birthdate, etc. Properties can be structured. Optionally, a property
can be constrained by a datatype
definition. For the property syntax,
please see here.
By default, the properties of an asset form a sequence
(an ordered list). However, it is also possible to arrange the
properties of an asset in a bag
construct and to define nested bags, choices, or sequences. The usage
of a bag is indicated by marking the Property section with the
bag operator (&).
The property section may also contain type
declarations.
- Constraints
- Constraints can be used to define additional restrictions for
properties. Constraints can be defined for single properties, across
properties, or across assets.
- Operations
- Operations define the access methods to asset instances. Operations
are specified as abstract method names. The semantics depend on the
implementation.
- Annotations
-
The definition of annotations is optional.
- Subject IDs
-
The definition of subject IDs is optional. A subject ID identifies the
concept or idea to which the asset relates. It usually refers to an
existing ontology. Subject IDs can be specified with or without a
prefix. If not prefix is specified, the subject ID is assumed to come
from the declared Default
Subject Ontology. A prefix may either be a Subject
Ontology Prefix, or it may specify an ontology namespace
explicitely be URI.
Subject IDs play a role
when models are merged. Assets from different models are candidates
for asset binding when the intersection of their subject ID sets is
not empty.
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