In UML, I diagram class B extending class A. In my actual class implementation, class B's constructor sets default values for protected members of class A. I know how to diagram default values for a class's owned members, but how do I diagram default values for fields which are not owned by the class?
In other words, how do I diagram default values in class B for fields defined in class A?
(note: I'm unable to change the class structure; I'm only diagramming)
This should be the way:
In order to create the picture I used Sparx Systems Enterprise Architect and the "Features & Properties → Override Attribute Initializers" context menu operation applied to the inherited field1 attribute.
So I think that this notation is correct because:
there is a remarkable tool that supports it
this notation is also used when showing slots in object instances
I'm not aware of any counterargument
You can use redefinition of attribute from class A in class B. Redefinition should set default value in class B. Or you can define instance specification (instance of class B) with slots. Fill slot value of specific attribute in instance of class B.
Related
I'd like to know if it is correct to add an Association Class to a Composition relationship?
For example (see figure below), can I add an Association Class (i.e. NameValue class) to the composition relationship between Name class and Value class? One Name can have multiple Value and one Value can only be attached to one Name. NameValue class stores the name-value pairs.
The reason why I create the association class (i.e. NameValue class) is that I need to create associations/relationships between NameValue class and other classes such as Class A.
If the answer is yes, is it recommended to turn the association class into a normal class?
Many thanks!
I'd like to know if it is correct to add an Association Class to a Composition relationship?
yes in an association-class the association can have an owner-end property being a composition, in formal/2017-12-05 there is nothing in § 11.5.3.2 Association Classes starting page 200 nor in § 11.8.2 AssociationClass [Class] against that even association-class has some constraints
NameValue class stores the name-value pairs.
note this is absolutely not the goal of the class of an association-class in UML, and not necessary the case when you implement an association-class
The reason why I create the association class (i.e. NameValue class) is that I need to create associations/relationships between NameValue class and other classes such as Class A
because NameValue is used at implementation level to stores the name-value pairs and then to implement the association(-class), in UML the diagram you want is :
(NameValue does not exist at UML level but only at implementation level)
If the answer is yes, is it recommended to turn the association class into a normal class?
At UML level the association-class do not exist for nothing, they make the model clear, so I do not recommend to not use class-association (but this is of course opinion-based)
In a UML class diagram, the value of one of the attributes of a class is a (typed) dictionary. What is a proper UML type annotation? (Within the box; not as an association.)
For example, in Python I would annotate this attribute with Dict[A,B] or possibly Mapping[A,B]. I am not asking about Python; this is just one example of a somewhat generic attribute annotation. I am open to the possibility that UML does not offer a language agnostic equivalent to this, but I am hoping that is not true.
Comment: I am asking about generic attribute annotation, directly with the class box. I do not wish to add a separate class box for Dict to the diagram. Therefore this is not a duplicate of How can I represent a Python dictionary in UML?
In UML Dict is typically model as a template class with two template parameters for instance named key and value.
Let's say you want the class C has the attribute a being a Dict[A,B], so you have a binding having the template param substitutions key -> A and value -> B.
There are several ways to show that in a class diagram.
For instance using the class DictAB to model Dict[A,B] :
or if you prefer :
But it is also possible to not use the auxiliary class DictAB and to use the textual representation of the binding expression (see formal/2017-12-05 § 7.3.4 page 26) :
Using this tool the classes corresponding to my code were created.
Each class has attributes with its getter and setter methods.
The attributes are created in the diagram but with the label << Property >> Without the corresponding methods, as you can see from the image.
Moreover, lists are not attributed to the type List , even if I change the association into aggregation.
The label << Property >> tells you precisely an attribute which correspond getter and setter?
I could not find anything about this label in the UML documentation
What you call label is a stereotype. Attributes with a <<Property>> stereotype are usually marked this way to tell a code generator that appropriate getter and setter methods shall be created if the target language supports (or requires) that.
Lists do not depend on the composition symbol but on the multiplicity which is barely readable, but I guess the dots near the associations are asterisks (for any multiplicity). The dots at the end of the associations are isOwned attributes (saying the the dot-marked class owns the association).
Is there a bulit-in way to obtain an entity name from the class object of an NSManagedObjectSubclass? I know that this can be readily determined from an instance of a subclass, but I want to ask the class itself. I can write a class function, but I would rather do this introspectively.
You can do it now by executing NSManagedObject.entity().name where NSManagedObject() is your subclass.
Check out mogenerator if you haven't already.
http://raptureinvenice.com/getting-started-with-mogenerator/
It adds a lot of missing features to core data. In particular it keeps you from having to regenerate your entity classes.
You could iterate thru the key values of the entities in the context:
[managedObjectContext registeredObjects];
If you've got a function like this inside a class called 'A'
public updateResponse(UpdateRequest updateRequest){
//...
}
Where UpdateRequest is another class which you create an object from
as in UpdateRequest ur = new UpdateRequest();
What is the relation between those two classes (Between 'A' and 'UpdateRequest')? I thought of an "usage" link between the interface of A and the class UpdateRequest. Is this correct? If not, what kind of link should it be?
If the diagram is a class diagram there is no relationship to be taken from your question.
The relationship between these two classes would be best show in a Sequence Diagram or an Activity Diagram. These show method calls etc, a method may be a member of a class in a class digram but it wouldn't really be expressed as a link. Unless you specifically wantto highlight this method, you could then put a usage link to the method on the class. But its not always good practice to do this for every method as you end up with a very messy class diagram.
It's always best to show these relationships in the diagrams you have to show the usage of the method.
EDIT:
How does the class A instance relate class UpdateRequest instance?
Q - What relationship are you trying to show? A - Method/function call.
Some class calls updateResponse and the information flow is an UpdateRequest instance.
Therefore... From left to right
SomeClass --| A
| | a = new UpdateRequest |
|<-----| |
| |
| updateResponse(a) |
|------------------------------------>|
Your sequence diagram might look something like this. There is no specific relationship drawn between class A and UpdateRequest as it is simply a piece of information that flows through the method call you have in your example. If the class was a member of the class, then the relationship would be shown directly on a class diagram, not applicable here. All the classes might (should) shown on a class diagram seperately, this can then be used as a reference point about all the objects in any diagram for those that need to analyse the design.