To be included in a MagicDraw project as a property extending a UML element, an attribute must be owned by a DSL customization element and stereotyped as «derivedPropertySpecification».
To create and specify a derived property
Select the customization element for which you want to create a derived property.
Warning
The derived property will be created for the stereotype or metaclass, defined as a customization target in the selected customization element specification.
Select Create Element > Property from the shortcut menu. The attribute is created.
Type the attribute name.
Note
The attribute’s name corresponds to the name of the derived property.
Type derived property names in camel case (i.e.,realizingActivities).
A property name defined in camel case will be displayed in separate words with the first word capitalized. For example, realizingActivities will be changed to Realizing Activities (visible in the user interface).
Apply the stereotype «derivedPropertySpecification» to this attribute. The resulting view of the Model Browsermust match the following picture:
Image Removed
Image AddedExample of customization element with the attribute for the derived property specification
Edit property values specifying the derived property in the attribute's Specification window.
Note
All properties are specified in the general specification pane. Some are also specified in the Tags specification pane. For detailed information, see the properties description table.
Warning
If you do not see the newly created derived property in the element’s Specification window, please read the following:
In the element’s Specification window, the specified derived property is visible by default only in the All properties mode. First, try switching to this mode. Also try changing the mode in which you want the derived property to be visible (click the Customize button).
If you have specified the derived property for the element (with the Used UML Properties property of DSL customization specified) you must add the newly created derived property to the element’s visible properties list. For detailed information, please refer to Derived properties visibility.
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The following table describes the properties specified for the derived property.
Property
Description
Specified in...
Name
The name of the property. This name will be added and visible in the specification of the element whose type is defined as a customization target.
General specification pane.
Type
The type of the derived property values. You may set a model element type or a data type (e.g., string, boolean, or integer from the UML Standard Profile) as a property value.
Tip
To display classes and components as property values, select the classifier as a type for the derived property value.
General specification pane.
Multiplicity
The multiplicity of the derived property values.
Tip
If the multiplicity is “0..1”, the derived property value will be shown as single. If the multiplicity is “0..*”, the derived property values will be shown as collection.
General specification pane.
Is Read Only/ isReadOnly
If true, the derived property is read-only. You cannot edit the result elements for the derived property value. If false, the property is read-write. You can edit the result elements for the derived property according to the expressions defined.
Note
Currently only read-only derived properties are supported.
General specification pane.
Tags specification pane.
Is Ordered
If true, the property values are always displayed in the same order. If false, the property values are displayed in nonpredictable order.
General specification pane.
Is Unique
If true, the property values are unique. The same element is displayed only once. If false, the property values may be displayed more than once.
General specification pane.
Expression/ expression
One or more expressions of the derived property. An expression defines the criterion for selecting result elements.
There are four possible expression types:
Simple (UML relationships, properties, and tags)
Multi properties chain (Meta Chain)
OCL
Binary (Reference to code class)
The criterion for selecting the result elements can also be any combination of the expression types above. For the detailed information, see Defining expressions.
General specification pane.
Tags specification pane.
Documentation
The text displayed as the derived property description in the element’s Specification windowand Properties panel.
Documentation specification pane.
customizationTarget
The specified derived property will be added to one or more element types (stereotypes and/ or metaclasses).
Note
The expression calculations begin from the element type of the customization target.
