Diagram Definition Facilities Based on Metamodel Mappings

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Diagram Definition Facilities Based on Metamodel
Mappings

• Edgars Celms, Audris Kalnins, Lelde Lace
• University of Latvia, IMCS, Riga, Latvia
• Edgars.Celms_at_mii.lu.lv, Audris.Kalnins_at_mii.lu.lv,
  Lelde.Lace_at_mii.lu.lv

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Business Modeling as DSM

• business process modeling - an unstable area with
  lot of competing notations having quite similar
  semantics (UML Activity diagrams one of them)
• generic modeling approach well fit for the area
• specific requirements
• graphical notations must be easily modifiable
• necessity to represent the same domain concepts
  via several graphic notations simultaneously

The presented approach offers an efficient
solution to this problem. The approach has been
tested practically in the Generic Modeling Tool
(University of Latvia, Exigen)
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Metamodel structure
Metamodel is split into domain package (typically
determined by domain standards) and presentation
package (graphical syntax)
Domain diagram
Domain package for Activities (part of UML
metamodel)
Diagram core (directed graph)
Presentation package for Activity Diagrams
There may be several presentation packages for
the same domain package alternative notations
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General Principles of Mapping
Classes in presentation package are mapped to
domain package
Generic mapping
Scaffolding principle (relates new mapping to the
existing one)
Context A inv BforA-gtnotEmpty() implies
owner.BCforAC BforA.owner
Context B inv AforB-gtnotEmpty() implies
owner.ACforBC AforB.owner
Correctness rules
Context AContainer inv contents -gt forAll (a
a.BforA-gtnotEmpty() ) and BCforAC-gtnotEmpty()
and BCforAC.contents -gt forAll (b
b.AforB-gtnotEmpty() )
Local completeness
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Simple Mapping Types
Mappings have types defined by schemas. There is
a type library.
Diagram mapping (type D)
Mapping schema for the type 1OT symbol to one
domain class. Symbol mapping relies on diagram
mapping (using scaffolding principle)
Mapping for Activity symbol actually the type
is 1OTD (domain element with definition)
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Mapping for Diagram Lines
Mapping schema for the type L1OT line to a
class in domain. It is based on mappings for
diagram and symbols. Additional constraint is
required for this type
Context Line inv startmappedLine.source.symbol
and end mappedLine.target.symbol
L1OT Mapping for control flows in activity
diagrams
In fact, all mappings for activity diagram are
shown here
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How it works in practice

• Steps to define a diagram
• build the metamodel domain and presentation
  packages
• for each presentation element find domain
  element(s) to which it maps (first diagram, then
  symbols, then lines)
• add mapping associations to the metamodel
• select the appropriate mapping type from the
  library (from 20)
• specify mapping details using the Definition
  tool in GMT, i.e., which metamodel elements
  actually correspond to the mapping schema
• for lines, specify end symbol types and
  multiplicities (at presentation level)
• define via Definition tool how symbol and line
  texts (compartments) map to attributes of domain
  classes (one or more)
• if necessary, add necessary explicit OCL
  constraints
• define style, icons etc. for presentation
  elements

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Alternative Diagrammatic Representations

• provide several presentation packages per domain
  package one for each diagram type
• define the mapping for each
• then the domain data can be modified through any
  of the diagram views - others are updated
  automatically
• the inverse mapping (consolidation) from domain
  to presentation is defined, to a significant
  degree automatically
• possible variations in representation
• what is a symbol in one diagram may be line in
  another (or box nesting)
• one presentation class may map to several domain
  classes and vice versa
• but the domain must support all representations
  anyway
• the correspondence between representations must
  be local

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Alternative Mapping ARIS eEPC
Part of ARIS eEPC (process) diagram mapped to the
same Activity domain
EventSymbol maps to the ControlFlow domain class
(which was represented by line in Activity
diagram)
L1LT - one more type of mapping - line
corresponds to a specified domain association
from a given class (pointed to by startMap)
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Alternative Mappings in Action
Activity diagram fragment
Equivalent eEPC diagram
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Simple application to MDA area
Class and Data Model diagram on a common domain -
for round-trip engineering
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Future Research - real MDA

• mappings and scaffolding principle may be used to
  define transformations between arbitrary
  metamodels - the proper QVT task
• arbitrary mappings can be defined as a set of
  ordered mapping rules
• a metamodel transformation language based on
  scaffolding principle currently under construction