Mapping dot notation in XMI

0
votes

Since 2.1 (or so) UML has introduced the so-called dot-notation which tells whether the role name besides the dot at an association end denotes an owned property within the opposite class. Since 2.5 OMG makes quite extensive use of that notation.

Now I wonder how this shall be mapped to XMI. The UML spec states on p. 717

UMLEdge (Association/Connector/InstanceSpecification/Property/ConnectorEnd , isAssociationDotShown enabled)

So I would expect to have an attribute in XMI like 

<ownedEnd isAssociationDotShown="true" xmi:type="uml:Property" ...

I tried that in Enterprise Architect, but (no wonder) it did not work. EA is using it's own extension 

<style value="Union=0;Derived=0;AllowDuplicates=0;Navigable=Unspecified;Owned=1;"/>

(it's the Owned=1 at the end). Of course I could mimic that notation, but

  1. that would only work for EA and
  2. I'd like to stick to a standard which I
  3. like to digest since I'm just guessing here.
1
umlxmi
Seems logical, though I'm not sure why one would not show the dot if it is owned? - muszeo
My issue is: how do I code that in XMI since there seems to be no (standard) construct to reveal the dot once imported into (say) EA. - qwerty_so
It seems that XMI doesn't support association end ownership dots. Maybe the assumption is that they have to be replaced by corresponding reference properties in the involved classes before serializing the class model to XMI. I guess the UML Diagram Interchange Specification should include support for them. - Gerd Wagner
@GerdWagner I also suspect that. The fact that the dot notation is "relatively new" might be the reason for this. Too bad. - qwerty_so

1 Answers

1
votes

The property isAssociationDotShown is a property of UmlDiagramWithAssociations (UML 2.5 § B.7.15) in the Annex B UML Diagram Interchange and is described as

isAssociationDotShown : Boolean [1..1] = false
Indicates whether dot notation for associations shall be used.

Notice that by default this property is false, which means the diagram should not show association dots.

The dot notation itself is defined in UML (UML 2.5 § 11.5.4) as

Ownership of Association ends by an associated Classifier may be indicated graphically by a small filled circle, which for brevity we will term a dot.

The mapping to XMI is really nothing more then the ownership of the member ends of the association.

Example from the UML specs: enter image description here

Example 1: Dot on both sides

The association in between InteractionFragment and Interaction has a dot on both sides, indicating that both ends are owned by the opposite classifier.
And indeed in the xmi provided by the OMG we find:

<packagedElement xmi:type="uml:Association" xmi:id="A_fragment_enclosingInteraction" name="A_fragment_enclosingInteraction" memberEnd="Interaction-fragment InteractionFragment-enclosingInteraction"/>

without owned ends. Both end are owned by the classifiers at the ends as OwnedAttributes

<ownedAttribute xmi:type="uml:Property" xmi:id="Interaction-fragment" name="fragment" type="InteractionFragment" isOrdered="true" aggregation="composite" subsettedProperty="Namespace-ownedMember" association="A_fragment_enclosingInteraction">
    <ownedComment xmi:type="uml:Comment" xmi:id="Interaction-fragment-_ownedComment.0" annotatedElement="Interaction-fragment">
        <body>The ordered set of fragments in the Interaction.</body>
    </ownedComment>
    <upperValue xmi:type="uml:LiteralUnlimitedNatural" xmi:id="Interaction-fragment-_upperValue" value="*"/>
    <lowerValue xmi:type="uml:LiteralInteger" xmi:id="Interaction-fragment-_lowerValue"/>
</ownedAttribute>

And the other one:

<ownedAttribute xmi:type="uml:Property" xmi:id="InteractionFragment-enclosingInteraction" name="enclosingInteraction" type="Interaction" subsettedProperty="NamedElement-namespace" association="A_fragment_enclosingInteraction">
    <ownedComment xmi:type="uml:Comment" xmi:id="InteractionFragment-enclosingInteraction-_ownedComment.0" annotatedElement="InteractionFragment-enclosingInteraction">
        <body>The Interaction enclosing this InteractionFragment.</body>
    </ownedComment>
    <lowerValue xmi:type="uml:LiteralInteger" xmi:id="InteractionFragment-enclosingInteraction-_lowerValue"/>
</ownedAttribute>

Example 2: Dot on one side

The association between StateInvariant and Constraint only has a dot on the Constraint end
The association itself is defined in the XMI as:

<packagedElement xmi:type="uml:Association" xmi:id="A_invariant_stateInvariant" name="A_invariant_stateInvariant" memberEnd="StateInvariant-invariant A_invariant_stateInvariant-stateInvariant">
    <ownedEnd xmi:type="uml:Property" xmi:id="A_invariant_stateInvariant-stateInvariant" name="stateInvariant" type="StateInvariant" subsettedProperty="Element-owner" association="A_invariant_stateInvariant">
        <lowerValue xmi:type="uml:LiteralInteger" xmi:id="A_invariant_stateInvariant-stateInvariant-_lowerValue"/>
    </ownedEnd>
</packagedElement>

The end without the dot is owned by the association.
The end with the dot is owned by StateInvariant as ownedAttribute.

<ownedAttribute xmi:type="uml:Property" xmi:id="StateInvariant-invariant" name="invariant" type="Constraint" aggregation="composite" subsettedProperty="Element-ownedElement" association="A_invariant_stateInvariant">
    <ownedComment xmi:type="uml:Comment" xmi:id="StateInvariant-invariant-_ownedComment.0" annotatedElement="StateInvariant-invariant">
        <body>A Constraint that should hold at runtime for this StateInvariant.</body>
    </ownedComment>
</ownedAttribute>

Importing into EA

Unfortunately there seems to be a bug in the xmi import function in EA as it looses the notion of owned ends (and so the dots). When importing it into EA (v14.5 BETA) the result is:

enter image description here