Specializing and extending the UML

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Specializing and extending the UML
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Extending the UML

• Stereotype
• Profiles (Specializing)
• Constraint
• Tagged value

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Stereotypes

• A class that defines how an existing metaclass
  (or other stereotype) may be extended, and
  enables the use of platform or domain specific
  terminology or notation in addition to the ones
  used for the extended metaclass. Certain
  stereotypes are predefined in the UML, others may
  be user defined.

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Stereotypes

• Stereotypes are one of the extensibility
  mechanisms in UML. Example ltltincludegtgt ltltextendgtgt
  distinguish dependencies in use case diagrams. A
  stereotype may be associated with a Class or
  Association (or other model element) in the
  definition of a profile. The main aspects in
  which a stereotype can modify the metaclass
  definition are

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Stereotypes

• 1) Presentation such as, first character of
  stereotype in lower case in front of elements
  name enclosed in guillmets icon or display
• 2) Additional properties for classes and
  attributes. The most important properties for an
  attribute (in addition to the name) are Type,
  Default Value, Multiplicity, and Unique.

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Stereotypes

• 2) Additional constraints In a profile only
  stereotypes can own constraints. The constraint
  can be named. In the CASE tool Rational Rose the
  constraints can be written in Java or OCL syntax.
• 3) Stereotypes can specialize or generalize other
  stereotypes.

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Stereotypes

• Stereotypes can be text or a graphic icon
• The icon can replace the normal class box

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What is a UML profile?

• A UML Profile is a predefined set of Stereotypes,
  Tagged Values, Constraints, and notation icons
  that collectively specialize and tailor the UML
  for a specific domain or process (e.g. Unified
  Process profile). A profile does not extend UML
  by adding any new basic concepts. Instead, it
  provides conventions for applying and
  specializing standard UML to a particular
  environment or domain.

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What is a UML profile?

• The UML profile was designed to structure and
  group together standard (extension)
  specialization to the UML model. The UML profile
  is at the heart of a strategic plan to formalize
  and handle the application development process
  using UML. This is called the Model Driven
  Architecture (MDA).
• A UML package is analogous to a folder used to
  organize a large diagram into several smaller
  ones. Packages are used to construct profiles.

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What is a UML profile?

• The purpose of a UML profile is to allow the
  construction and interchange of UML models that
  require semantic specifications that express
  semantic detail beyond what can be expressed with
  standard UML.

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What is a UML profile?

• Specializing UML for technology implementations
  (language mappings) Every technical target,
  such as programming language, or middleware or
  library or database is a natural candidate for
  defining a dedicated UML profile.
• UML profile for CORBA
• UML profile for EJB (Enterprise Java Beans)
• UML profiles for C, or for Java,
• UML profiles for specific RDB such as ORACLE.
• UML for GIS see hand out and http//www.isima.fr/
  kang/pinet/kang.pdf

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What is a UML profile?

• Specializing UML for specific application domains
  
• Domain specialists in e.g. the finance or
  manufacturing domains have to use profiles
  cautiously. Very often, application domains only
  require predefined model libraries or template
  libraries. Using profiles in this context might
  be overkill.
• However, there are some needs for specializing
  UML which originate in horizontal application
  domains. For example, geographic applications
  need to express a specific way of defining
  geographic constraints between elements, that do
  not exist in other development areas.

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Part of a GIS profile from Kang et
al. http//www.isima.fr/kang/pinet/kang.pdf
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UML Extensions

• UML has the following extension mechanisms.
• Stereotypes
• Tagged Values
• Constraint
• A stereotype defines how an existing metaclass
  may be extended, and enables the use of platform
  or domain specific terminology or notation in
  place of or in addition to the ones used for the
  extended metaclass.

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What is a UML profile?

• Profiles generically extend the UML through the
  use of stereotypes that are most often
  language-specific, provide a common graphical
  notation and vocabulary, and define a subset of
  the UML metamodel (MOF).

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What is a UML profile?

• Profiles available in CASE tools such a Poseidon,
  ArgoUML, Rational Rose.

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What is a UML profile?

• A profile is an extension to the core UML that
  keeps the UML metamodel intact, in other word it
  obeys the rules of UML. A UML profile is a subset
  of UML that is necessary and sufficient for a
  given development effort (e.g. Testing, WAP, or
  GIS). For example, UML Testing Profile defines a
  language for designing, visualizing, specifying,
  analyzing, constructing and documenting the
  artifacts of test systems. UML profiles are
  defined in the UML infrastructure volume of UML
  2.0. Profiles are packages that are linked to
  other packages in a model by using the ltltapplygtgt
  dependency. Model elements in the model package
  can then use the features that are in the
  profile, typically stereotypes.

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UML example GIS profile

• The following is part of a description of a car
  sharing system
• Each member of the car sharing pool has an
  address that consists of neighborhood and a
  region. It is required to construct a class for
  the car sharer, the address, the neighborhood,
  and the region.
• In order to handle location information it has
  been decided to attach a Geographical Information
  System (GIS) system to the car sharing system.
  The GIS has been modeled as a UML profile called
  GIS.
• The UML profile mechanism was used to construct
  the profile in the next slide. This profile
  extends Class with Point and Region stereotypes.
  It also extends the UML association with an
  association stereotype called LocatedIn which
  associates Point with Region.

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UML example GIS profile
The UML profile mechanism was used to construct
the profile above. This profile extends Class
with Point and Region stereotypes. It also
extends the UML association with an association
stereotype called LocatedIn which associates
Point with Region. Draw a UML diagram that
applies the GIS profile to the car sharing
package.
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Profile WML Example

• The Wireless Markup Language (WML) is used to
  describe content for wireless applications. The
  Wireless Access Protocol (WAP) is a standard used
  to deliver Internet content to wireless devices
  such as mobile phones and Personal Digital
  Assistants (PDAs). WML uses the metaphor of decks
  of cards. Assume that a WAP/WML application
  consists of a single deck. Each deck contains a
  number of cards each card displays a screen-full
  of information on a mobile device. When cards
  from a deck are transferred to a mobile device,
  the user can move between cards using a simple
  next and previous command. The UML profile on
  the next slide represents WAP/WML functionality.

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Part of UMLs core MOF
Part of the application domain
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Profile WML Example

• We will describe the roles of the stereotypes
  used in the WAP package tab, the Application
  class, and in the Next association. We will also
  describe the relevant UML extension mechanism.

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Profile WML Example

• The ltltprofilegtgt stereotype in the package tab
  indicates that the package is a profile and
  package name is WAP.
• Black arrows indicate that a new class extends
  the UML metaclasses Class and Association. We do
  not describe details of higher order UML or MOF.
• The figure indicates the following stereotypes
  for classes have been created ltltapplicationgtgt,
  ltltdeckgtgt , ltltcardgtgt and the following stereotypes
  for association have been created ltltdeliversgtgt ,
  ltltnextgtgt , ltltpreviousgtgt .

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Profile WML Example

• The next slide shows part of a car sharing
  system. The semantics of the diagram are as
  follows. The CarMatchDatabase class represents
  the complete car sharing database. The
  CarMatchInformation represents a result set from
  a database query. Each result set consists of one
  or more CarMatch objects representing actual car
  sharing records. CarMatch objects are linked
  together with two associations called previous
  and next.

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Profile WML Example
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Profile WML Example

• We will draw a diagram showing the application of
  the WAP profile to the CarSharer package using
  the following mappings.

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Application Profile Mapping
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Profile WML Example

• Description Each new stereotype in the WAP
  profile is applied as appropriate to each class
  or association in the CarSharer package, as per
  mapping. The ltltapplygtgt dependency is used to
  indicate the application of the profile to the
  package.

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Profile Example
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Profile Example

• The extension mechanism extends the metaclass
  definition of one or more metaclasses Class and
  Accociation (the original metaclass definitions
  are still available for normal use). Then when
  the profile is applied new classes with the new
  stereotype have the newly defined features.
  Hence, the CarMatch class has whatever was
  defined in Card. The stereotypes Application,
  Deck, and Card are all extensions of the
  metaclass Class. The stereotypes Delivers, Next
  and Previous are all extensions to the metaclass
  Association. The application allows the UML user
  to avail of previously defined specifications
  (usually domain specific).

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Constraints

• Constraints are a semantic condition or
  restriction. They are standard UML feature. They
  can be expressed in natural language text,
  mathematically (FOPL SETS) formal notation, or
  in a machine-readable language e.g. OCL for the
  purpose of declaring some of the semantics of a
  model element. They are used in combination with
  tagged definitions to define the characteristic
  of stereotypes in profiles. A constraint defines
  a relationship between model elements that must
  be true subset xor (multiplicity not enough
  for xor). Constraints can be on attributes,
  derived attributes, associations and classes.

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Tagged values

• Many stereotyped model elements have properties
  that cannot be represented graphically. These can
  defined in the profile as tagged definitions and
  are shown in the model as tagged values. Tagged
  values consist of a tag or name and an associated
  value (e.g. CoordSystem LatLong or Boolean
  tagged value abstract isPropertyName). Tagged
  definitions are the attributes of the stereotypes
  in the profile and are typically shown in
  comments attached to the stereotyped model
  elements.

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Tagged values

• Persistence is shown using a tagged value

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Constraints as a tagged Boolean assertion

• This constraints is represented as a togged
  Boolean assertions attached to a model element.
• they are attached to one or more model element
• this shows a note containing a class constraint