10.3 The UML to Web Mapping

This section describes the transformation definition for transforming PIMs in UML to models of Web components. The definition is identical to the rules used in section 5.3.1. The source language is the simplified UML, defined in the metamodel in Figure 10-1. The target language is the Web model described in section 5.3. The metamodel for Web components used is depicted in Figure 10-4. The rules depend on the UML to EJB transformation rules. This is because the generated Web components depend on the EJB components, similar to the fact that EJB Entity Components depend on the Tables of the relational model.

Figure 10-4. Simplified Web metamodel

graphics/10fig04.gif

As already explained in section 5.3.1. the UML to Web transformation rules are very similar to the UML to EJB transformation rules. This is also the reason why both transformation definitions use the same query operations defined in section 10.2.1.

  1. Each class that is not the part of a composite aggregation is mapped to a Web component. Classes that are composite parts of other classes do not conform to this rule and are transformed by the next rule. This rule formalizes rule 1 in section 5.3.1.

      Transformation  ClassToWebComponent (UML, Web) {  source  class            : UML::Class;  target  webComponent     : Web::WebComponent;      rootDataClass    : Web::WebDataClass;      dataSchema       : Web::WebDataSchema;      servingAttribute : Web::WebServingAttribute;  source condition   not  class.feature->exists(end : UML::AssociationEnd                                            end.otherEnd.composition);  target condition  servingAttribute.class = webComponent  and  servingAttribute.type  = rootDataClass  and  rootDataClass.package  = dataSchema;  unidirectional;   mapping  class.name <~> webComponent.name;      class.name <~> rootDataClass.name;      class.name <~> servingAttribute.name;      class.name <~> dataSchema.name;      class.getAllContained(Set(UML::Class){}).operations() <~>                                                webComponent.feature;      class.feature->select(oclKindOf(UML::Attribute)  or  oclKindOf(UML::AssociationEnd)) <~>                                              rootDataClass.feature;      class <~> webComponent.usedComponent; } 
  2. The following transformation defines the mapping from a UML class to a Web data class. The source condition states that this transformation can only be applied when the UML class is part of a composite aggregation. This rule formalizes a part of rule 2 in section 5.3.1.

      Transformation  ClassToDataClass (UML, Web) {  source  class : UML::Class;  target  nonRootClass : Web::WebDataClass;  source condition  class.feature->exists(end : AssociationEnd                                            end.otherEnd.composition);  unidirectional;   mapping  class.name <~> nonRootClass.name;      class.feature->select(oclKindOf(UML::Attribute)  or  oclKindOf(UML::AssociationEnd)) <~>                                              rootDataClass.feature;      class.getOuterMostContainer() <-> nonRootClass.package; } 
  3. Each association is transformed into a Web association. This rule formalizes rule 3 in section 5.3.1.

      Transformation  AssociationToDataAssociation (UML, Web) {  source  assoc     : UML::Association;  target  dataAssoc : Web::WebDataAssociation;  source condition  assoc.end->exists(composition);  unidirectional  ;  mapping  assoc.name                    <~> dataAssoc.name;      assoc.end                     <~> dataAssoc.end;      assoc.getOuterMostContainer() <~> dataAssoc.package; } 
  4. This rule formalizes a part of rule 4 in section 5.3.1.

      Transformation  AssociationClassToDataClass (UML, Web) {  source  associationClass : UML::AssociationClass;  target  nonRootClass     : Web::WebDataClass;  source condition  class.feature.->exists(end : AssociationEnd                                            end.otherEnd.composition);  unidirectional  ;  mapping  associationClass.name <~> nonRootClass.name;      associationClass.feature->select(oclKindOf(UML::Attribute)  or  oclKindOf(UML::AssociationEnd)) <~>                                               rootDataClass.feature;      associationClass.getOuterMostContainer() <~>                                               nonRootClass.package; } 
  5. The following rule formalizes rule 5 in section 5.3.1. This is a straightforward transformation from UML attribute to Web attribute.

      Transformation  UMLAttributeToWebAttribute (UML, Web) {  source  umlAttribute : UML::Attribute;  target  webAttribute : Web::WebAttribute;  unidirectional  ;  mapping  umlAttribute.name <~> webAttribute.name;      umlAttribute.type <~> webAttribute.type; } 
  6. This rule defines a transformation from a UML association end to a Web association end. The condition of this rule states that it is only applicable if the transformed association end is not crossing a Web data schema. In this case, the type of the Web association end is a Web data class. This rule formalizes a part of rule 3 in section 5.3.1.

      Transformation  UMLAssociationEndToWebAssociationEnd(UML, Web) {  source  umlAssociationEnd : UML::AssociationEnd;  target  webAssociationEnd : Web::WebAssociationEnd;  source condition  umlAssociationEnd.association.oclIsTypeOf(Association)  and  umlAssociationEnd.class.getOuterMostContainer() =                      umlAssociationEnd.type.getOuterMostContainer();  unidirectional  ;  mapping  umlAssociationEnd.name        <~> webAssociationEnd.name;      umlAssociationEnd.upper       <~> webAssociationEnd.upper;      umlAssociationEnd.lower       <~> webAssociationEnd.lower;      umlAssociationEnd.composition <~>                                      webAssociationEnd.composition;      umlAssociationEnd.type        <~>                 webAssociationEnd.type.oclAsType(Web::WebDataClass); } 
  7. This rule also defines a transformation from a UML association end to a Web association end. The condition of this rule states that it is only applicable if the transformed association end is crossing a Web data schema. In this case, the type of the Web association end is an EJB key class. This rule formalizes a part of rule 3 in section 5.3.1.

      Transformation  UMLAssociationEndToWebAssociationEnd(UML, Web) {  source  umlAssociationEnd : UML::AssociationEnd;  target  webAssociationEnd : Web::WebAssociationEnd;  source condition  umlAssociationEnd.association.oclIsTypeOf(Association)  and   not  umlAssociationEnd.class.getOuterMostContainer() =                      umlAssociationEnd.type.getOuterMostContainer();  unidirectional  ;  mapping  umlAssociationEnd.name  <~> webAssociationEnd.name;      umlAssociationEnd.upper <~> webAssociationEnd.upper;      umlAssociationEnd.lower <~> webAssociationEnd.lower;      umlAssociationEnd.composition <~>                                      webAssociationEnd.composition;      umlAssociationEnd.type  <~>                  webAssociationEnd.type.oclAsType(EJB::EJBKeyClass); } 
  8. The following rule transforms association ends from an association class into associations in the Web data schemas. This is because we need two associations per association class to implement them in the Web model, which does not support association classes in the metamodel. This rule formalizes a part of rule 4 in section 5.3.1.

      Transformation  UMLAssociationClassEndToWebAssociation(UML, Web) {  source  umlAssociationEnd  : UML::AssociationEnd;  target  webAssociation     : Web::WebAssociation;      webAssociationEnd1 : Web::WebAssociationEnd;      webAssociationEnd2 : Web::WebAssociationEnd;  source condition  umlAssociationEnd.upper <> 1  and  umlAssociationEnd.association.oclIsTypeOf(AssociationClass)  and  umlAssociationEnd.association.getOuterMostContainer() =                      umlAssociationEnd.type.getOuterMostContainer();  target condition  webAssociationEnd1.lower = 0  and  webAssociationEnd1.upper = *  and  webAssociationEnd2.lower = 1  and  webAssociationEnd2.upper = 1  and  webAssociationEnd1.composition = false  and  webAssociationEnd1.association = webAssociation  and  webAssociationEnd2.association = webAssociation;  unidirectional  ;  mapping  umlAssociationEnd.type.name   <~> webAssociationEnd2.name;      umlAssociationEnd.composition <~>                                      webAssociationEnd2.composition;      umlAssociationEnd.type        <~>                webAssociationEnd2.type.oclAsType(Web::WebDataClass);      umlAssociationEnd.type        <~>               webAssociationEnd1.class.oclAsType(Web::WebDataClass);      umlAssociationEnd.association.name <~>                                             webAssociationEnd1.name;      umlAssociationEnd.association <~>                webAssociationEnd1.type.oclAsType(Web::WebDataClass);      umlAssociationEnd.association <~>               webAssociationEnd2.class.oclAsType(Web::WebDataClass); } 
  9. If we cross different Web data schemas, we only need an association end pointing out of the Web data schema to an EJB key class. This rule formalizes a part of rule 4 in section 5.3.1.

      Transformation  UMLAssociationClassEndToWebAssociation(UML, Web) {  source  umlAssociationEnd  : UML::AssociationEnd;  target  webAssociationEnd2 : Web::WebAssociationEnd;  source condition  umlAssociationEnd.upper<>1  and  umlAssociationEnd.association.oclIsTypeOf(UML::AssociationClass)  and   not  umlAssociationEnd.association.getOuterMostContainer() =                               umlAssociationEnd.type.getOuterMostContainer();  target condition  webAssociationEnd2.lower = 1  and  webAssociationEnd2.upper = 1;  unidirectional  ;  mapping  umlAssociationEnd.type.name   <~> webAssociationEnd2.name;      umlAssociationEnd.composition <~>                                      webAssociationEnd2.composition;      umlAssociationEnd.type        <~>                 webAssociationEnd2.type.oclAsType(EJB::EJBKeyClass);      umlAssociationEnd.association <~>              webAssociationEnd2.class.oclAsType(Web::WebDataClass); } 
  10. An Operation in UML becomes a Web action in the Web model. This rule formalizes a part of rule 6 in section 5.3.1.

      Transformation  UMLOperationToBusinessMethod(UML, Web) {  source  umlOperation   : UML::Operation;  target  webAction : Web::WebAction;  unidirectional  ;  mapping  umlOperation.name      <~> webAction.name;      umlOperation.parameter <~> webAction.parameter; } 
  11. UML Parameters are transformed into Web Parameters. This rule formalizes another part of rule 6 in section 5.3.1.

      Transformation  UMLParameterToWebParameter(UML, Web) {  source  umlParameter : UML::Parameter;  target  webParameter : Web::WebParameter;  unidirectional  ;  mapping  umlParameter.name <~> webParameter.name;      umlParameter.type <~> webParameter.type; } 

Analogous to the UML to EJB transformation, we need to transform UML data types to Web data types. This transformation is not defined here, but there should be a number of (predefined) transformations at the lowest level of UML to Web data types. The definition below simply states that there must be such a transformation from UML to Web data types.

  Transformation  UMLDataTypeToWebDataType (UML, Web) {  source  umlDataType : UML::DataType;  target  webDataType : Web::WebDataType;  unidirectional  ; } 


MDA Explained. The Model Driven Architecture(c) Practice and Promise 2003
Project Leadership (The Project Management Essential Library)
ISBN: N/A
EAN: 2147483647
Year: 2004
Pages: 118

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