- Assets -
Assets are the basic building blocks of AOM. Unlike the
flavors of Entity Relationship Modeling, AOM does not separate between
and relationships. In AOM both entities and relationships are
assets (the relationships are reified). In this respect is AOM closer
relational approach (where both entities and relationships are
tables). This approach allows to represent n-ary relationships
similarly higher order relationships (i.e. relationships between
Assets can be concrete or abstract. Abstract assets
instances. They can be used for inheritance
definitions. Abstract assets are denoted by a label
Assets are connected via directed arcs.
- 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. Name formulas
may be used as asset name.
- optional. An image in the top right corner may be used for
- 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
- Name formulas may be used as
a display label.
- 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.
- 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.
- 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
- Constraints can be used to
define additional restrictions for properties. Constraints can be
defined for single properties, across properties, or across
- Operations define the access
methods to asset instances. Operations are specified as abstract method
names. The semantics depend on the implementation.
- The definition of annotations
- 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.
Contact: support 'at' aoModeling.org