UML Profile for MOF
- Author:
- Martin Matula, NetBeans / Sun
Microsystems
- History:
-
Available in the CVS
Introduction
This document describes UML Profile for MOF supported by
UML2MOF conversion tool.
The profile defined here is based on OMG's UML Profile for MOF described
in chapter 6 of
UML
Profile for EDOC standard (OMG document ad/01-08-19). A separate profile
was created (i.e. the standard could not be fully reused) for the
following reasons:
- The standard defines mapping from UML to MOF 1.3. Mapping from UML to
MOF 1.4 was needed.
- The standard uses several UML elements that are not supported
by known UML tools.
- There are several bugs in the standard.
For convenience, differences between
OMG's standard UML Profile for MOF and profile defined herein are
discussed at the end of each sub-section.
UML Representation of MOF Elements
Below is a simple table showing how each MOF element maps to a
corresponding UML element in a profile (if there are several variants, they
are separated by a semicolon). Click on a MOF element to go to
a detailed description of the mapping.
Detailed Mapping
This sections describes mapping of all elements and their features in
detail. The mapping decsribed herein is bidirectional, although it is
defined from MOF-to-UML perspective. Detailed description of mapping for
each of the elemenets contains of the following subsections:
- Tags - defines extra tags that are added to UML model in order
to be able to represent values of some MOF attributes.
- Feature Map - table describing mapping between the particular
features of a MOF element and UML elements.
- Limitations - names limitations of the MOF-to-UML mapping
(if certain MOF constructs cannot be expressed in UML using this
profile)
- UML Model Constraints - lists constraints to be preserved in UML model
in order to be compliant with this profile (i.e. to be mappable to
MOF)
- OMG Profile - describes differences (if any) between this profile
and the standard MOF Profile for UML defined by OMG.
Here are the basic mapping rules shared by all the elements:
Tags
| Tag |
Value |
| documentation | any string |
Feature Map
| MOF Feature |
UML |
| name | ModelElement.name |
| annotation | body of the first comment in
ModelElement.comment; value of documentation tag |
| container | ModelElement.namespace |
| constraints | ModelElement.constraint |
UML Model Constraints
Every UML ModelElement that maps to MOF ModelElement must have a
name.
OMG Profile
Lacking support for ModelElement.comment - mapping of annotation
attribute fully relies on the documetation tag. However most of the
UML tools store documentation for model elements in instances of
Comment classes.
Detailed mapping of other features specific to each MOF class follows.
AliasType is represented by an instance of UML DataType with <<alias>>
stereotype.
Tags
| Tag |
Value |
| org.netbeans.uml2mof.aliasFor | fully qualified
name (with individual simple names separated by ".") of a classifier from the same model |
Feature Map
| MOF Feature |
UML |
| type | classifier that the fully qualified name in
value of org.netbeans.uml2mof.aliasFor tag resolves to |
OMG Profile
Lacks definition of AliasType mapping as the standard profile is
based on MOF 1.3.
MOF Association maps directly to UML Association.
UML Association stereotyped as <<implicit>> is ignored
by the profile and is not mapped to a MOF Association.
Tags
| Tag |
Value |
| org.omg.uml2mof.isDerived | true
or false (default) |
Feature Map
| MOF Feature |
UML |
| isRoot | isRoot |
| isLeaf | isLeaf |
| isAbstract | isAbstract |
| visibility | always set to
public_vis |
| supertypes | generalization.parent |
| contents | ownedElement,
connection, taggedValue |
| isDerived | value of
org.omg.uml2mof.isDerived tag |
Limitations
The order of contents reference are not fully preserved because UML
has a separate associations for ownedElement and connection.
UML Model Constraints
An Association must have exactly two ends.
OMG Profile
There is no way how to map derived associations (isDerived tag is
missing).
MOF AssociationEnd is directly mapped to UML AssociationEnd.
Tags
Feature Map
| MOF Feature |
UML |
| type | participant |
| multiplicity | lower and upper
is determined by multiplicity.range, isOrdered is mapped to
ordering (where true corresponds
to ordered) and isUnique maps always to true |
| aggregation | aggregation (UML aggregate matches
MOF shared) |
| isNavigable | isNavigable |
| isChangeable | changeability
(changeable maps to true) |
UML Model Constraints
An association must have exactly two ends.
UML changeability must be either changeable or
frozen.
Multiplicity must have a single range.
OMG Profile
There is a bug in the profile which states that MOF feature "type"
is mapped to UML feature "type". However UML AssociationEnd does not
have a reference called "type" - it uses "participant" reference for this
purpose.
MOF Attribute is straightforwardly mapped to UML Attribute.
Tags
| Tag |
Value |
| org.omg.uml2mof.isDerived | true or
false (default) |
| org.omg.uml2mof.isUnique | true or
false (default) |
Feature Map
| MOF Feature |
UML |
| multiplicity | lower and upper
are determined by multiplicity.range, isOrdered is mapped to
ordering (where true corresponds
to ordered) and isUnique maps to
org.omg.uml2mof.isUnique tag value. |
| isChangeable | changeability (changeable
maps to true, otherwise false) |
| isDerived | value of org.omg.uml2mof.isDerived
tag |
MOF Class maps to UML Class with no stereotypes.
Tags
| Tag |
Value |
| org.omg.uml2mof.isSingleton | true or
false |
Feature Map
| MOF Feature |
UML |
| isRoot | isRoot |
| isLeaf | isLeaf |
| isAbstract | isAbstract |
| visibility | always set to
public_vis |
| supertypes | generalization.parent |
| singleton | value of org.omg.uml2mof.isSingleton
tag (false by default) |
| contents | ownedElement followed by
feature (in order) and taggedValue |
Limitations
The order of contents reference is not fully preserved because UML
has separate associations for features and other owned elements.
MOF CollectionType is represented in UML as a class with
<<collection>> stereotype. Such class must contain
attribute named
items that determines the element type and
multiplicity of the collection.
Feature Map
| MOF Feature |
UML |
| multiplicity | multiplicity of items
attribute |
| type | type of items
attribute |
UML Model Constraints
Class representing a collection must contain an attribute named
items.
OMG Profile
Lacks definition of CollectionType mapping as the standard profile is
based on MOF 1.3.
TBD
TBD
MOF Enumerations can be represented by either UML Enumerations or classes
with <<enumeration>> stereotype.
Feature Map
| MOF Feature |
UML |
| labels | list of names of literals contained by a corresponding UML
enumeration or names of attributes if the enumeration is represented by
UML class (attribute types, multiplicities, etc. are ignored) |
OMG Profile
Lacks definition of EnumerationType mapping as the standard profile is
based on MOF 1.3.
MOF Exception is maps to UML Class with <<exception>>
stereotype.
Feature Map
| MOF Feature |
UML |
| contents | feature, ownedElement, taggedValue |
| scope | always
classifier_level |
| visibility | always maps to
public_vis |
OMG Profile
Maps MOF Exception to UML Exception. UML Exception is however not
supported in Class diagrams by most of the known UML tools.
MOF Import is represented by UML dependency stereotyped as
<<import>> or <<clustering>>.
Feature Map
| MOF Feature |
UML |
| container | client |
| importedNamespace | supplier |
| isClustered | true if this dependency
is stereotyped as <<clustering>>, false
if stereotyped as <<import>> |
| visibility | always true |
UML Model Constraints
Element on client end of the dependency must be a UML Package/Model
mapped to a MOF Package.
OMG Profile
Maps MOF Import to UML ElementImport that is not supported by most
of the known tools.
MOF Operation directly maps to UML Operation.
Tags
| Tag |
Value |
| org.netbeans.uml2mof.raisedExceptions | Multiple
values or one value containing comma-separated list of fully
quialified names of classes corresponding to MOF
Exceptions |
Feature Map
| MOF Feature |
UML |
| contents | parameter, taggedValue |
| isQuery | isQuery |
| exceptions | Exceptions corresponding to the fully
qualified names in values of
org.netbeans.uml2mof.raisedExceptions tag |
| scope | Feature.ownerScope |
| visibility | always maps to
public_vis |
See Feature mapping for mapping of inherited
features.
OMG Profile
Raised exceptions are supposed to be linked via raisedSignal
reference (with no need for a separate tag for them). This reference is however not supported
by most of the tools.
MOF Parameter contained by an Operation is mapped to UML Parameter.
MOF Parameter contained by an Exception is mapped to UML Attribute.
Tags
| Tag |
Value |
| org.omg.uml2mof.multiplicity | upper and lower multiplicity bound
of the paramter values separated by two dots ("..") - e.g. 1..1 (default) or 0..* (zero to many) |
| org.omg.uml2mof.isOrdered | true or
false (default) |
| org.omg.uml2mof.isUnique | true or
false (default) |
Feature Map
| MOF Feature |
UML |
| direction | kind for operation parameters,
out_dir for exception parameters |
| multiplicity | lower and upper are mapped to multiplicity.range, however
if the org.omg.uml2mof.multiplicity tag is present, it takes the precedence,
isOrdered is mapped to ordering (for Exception parameters) or value of
org.omg.uml2mof.isOrdered tag (for Operation parameters), isUnique
is mapped to the value of org.omg.uml2mof.isUnique tag |
| type | type |
OMG Profile
Introduces a new tag for multiplicity although both UML Attribute and
UML Parameter have multiplicity parameter for that purpose. This tag is preserved as some
UML tools do not support multiplicity on Parameters, so both the tag and the multiplicity attribute
are taken into account by this profile, the tag value takes the precedence.
In case of UML Exception neither special tag for isOrdered is needed
as this is provided by ordering attribute.
Outermost MOF Package is mapped to UML Model or UML Package, both with
<<metamodel>>, the nested MOF Package is represented by
either UML Model or UML Package (i.e. the <<metamodel>>
stereotype is not necessary in case of nested packages).
Tags
| Tag |
Value |
| org.omg.uml2mof.hasImplicitReferences | true (default) or false |
Feature Map
| MOF Feature |
UML |
| container | namespace or null if the
namespace is either null or not mapped to a MOF
Package |
| contents | ownedElement, taggedValue |
| isRoot | isRoot |
| isLeaf | isLeaf |
| isAbstract | isAbstract |
| visibility | always set to
public_vis |
| supertypes | other packages on supplier end of
UML dependencies stereotyped as <<subtyping>> that
binds them to this package. |
Limitations
The order of contents are not fully preserved when rendered using
the profile as UML has separate associations for ownedElement and
taggedValue.
UML Model Constraints
UML Model/Package representing a nested MOF Package must not have a
tag of org.omg.uml2mof.hasImplicitReferences.
OMG Profile
While the standard profile allows MOF Packages to be represented by
UML Models only, UML Models are not supported by some existing UML
tools. Also org.omg.uml2mof.clusteredImport tag is introduced for
clustered imports declarations. This profile solves clustered
imports differently (see Import mapping).
Package subtyping is handled by a standard
generalization.parent reference which was replaced in this mapping
by a stereotyped dependency
as package subtyping is not supported by most of the known UML
tools.
Mapping of PrimitiveTypes is based on their names. UML datatype with no stereotype and with the
same name as one of the MOF primitive types in PrimitiveTypes package
is mapped to that type (no matter what UML package it is in). All the
other UML data types with no stereotype are mapped to instances of
MOF PrimitiveType class (with a given name) residing in a MOF package
corresponding to the UML package they are in.
Limitations
Modeling of primitive types distinct from the MOF standard primitive
types (defined in PrimitiveTypes package) but with the same name is
not supported by this profile.
OMG Profile
Lacks definition of PrimitiveType mapping as the standard profile is
based on MOF 1.3.
MOF Reference can be
represented by UML Attribute with <<reference>>
stereotype.
Also, if the UML package corresponding to MOF outermost package does
not have the value of tag org.omg.uml2mof.hasImplicitReferences set
to
false, then a MOF Reference is implied by each
eligible UML AssociationEnd. An end is considered eligible if it is
navigable, there is no explicit MOF Reference for that end within
the same outermost package and the end's association is owned by the
same package that owns its opposite end's type (to not create
circular package dependencies).
Tags
| Tag |
Value |
| org.omg.uml2mof.referencedEnd | fully qualified name of an association end |
Feature Map
| MOF Feature |
UML |
| scope | always maps to instance_level |
| visibility | always maps to
public_vis |
| refenrecedEnd | AssociationEnd corresponding to the fully qualified name in the value
of org.omg.uml2mof.referencedEnd tag. |
Values for the inherited attributes of multiplicity, isChangeable
and type are fully infered from the corresponding association end
(values of these attributes for the corresponding UML Reference are
ignored).
In case of implicit references, name and annotation are also taken
from the association end.
StructureField is represented in UML as an attribute of a UML class
representing StructureType.
Tags
None.
Feature Map
Please note that StructureField does not have a multiplicity
attribute, thus multiplicity specified on the corresponding UML
attribute is ignored when mapping from UML to MOF.
OMG Profile
Lacks definition of StructureField mapping as the standard profile is
based on MOF 1.3.
StructureType is mapped to a class with <<structure>>
stereotype.
Feature Map
| MOF Feature |
UML |
| contents | Namespace.ownedElement followed by
Classifier.feature (in order) |
OMG Profile
Lacks definition of StructureType mapping as the standard profile is
based on MOF 1.3.
MOF Tag is mapped to UML TaggedValue.
Feature Map
| MOF Feature |
UML |
| tagId | name |
| values | value |
| elements | modelElement |
Limitations
Tags without prefix or with org.omg.uml2mof and org.netbeans.uml2mof prefixes are ignored when
mapping from UML to MOF and thus they should not be used in MOF metamodels.
