Created December 31, 2009
Last updated December 31, 2009
Dependency
In this page, I will explain the dependency in the class diagram
1.
When I began to study the UML , I could not understand the dependency. Because , It is not written in the book so much.
But , when we design the software , there are often the dependencies. After all, I was troubled because I had no idea.
To decrease person like past me , I created this page.
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Note.
1: In this page , I will explain supposing that you know the UML a little. But , whether you don't know the UML , I will try so that you can understand. And , in this page , the UML version is 2.0.
The dependency 1 means that when a element 2 is changed , other element is dependent 3.
When the ClassA is dependent on the ClassB , this is noted by the arrow of short dashed line like in the Figure 1.
Figure 1 - The notation of the dependency ( When the ClassA is dependent on the ClassB )
When the ClassA is dependent on the ClassB and the ClassB is dependent on the ClassA ( When bidirectional dependency) , this is noted like in the Figure 2.
Figure 2 - When bidirectional dependency
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Note.
1: If you need the details , please read the Fig7.17 on the page 32 and the "7.3.12 Dependency (from Dependencies)" on the page 58 in the
UML2.0 Sepecification.
2: The element means all things composing the model. For example , there are the class , operation , comment , association and so on in the class diagram . And there are the actor , usecase and so on in the usecase diagram.
If you need the details of the element , please read the Fig7.3 on the page 23 and "7.3.14 Element (from Kernel)" on the page 60 in the
UML2.0 Sepecification.
If you think to take an examination of the
OCUP Fandamental , I think that you should stuty it.
3: Because I had the course that I only explained the dependency in the class diagram , I supplement. Actually , the dependency is able to be used expect between the classes too ( it is able to be used between named elements ) .
- Usage 1
The object of the ClassA does not have the object of the ClassB ( There is no association from the ClassA to the ClassB ) 2. But the operation of the ClassA use the ClassB such as following.
- In the operation of the ClassA , an object of the ClassB is created.
- At the return value , the parameter or the exception type of the operation of the ClassA , the ClassB is used.
- In the operation of the ClassA , the class-scope operation of the ClassB is called.
In the end, when there is no association from the ClassA to the ClassB and the ClassB is used in the oparetion of the ClassA in the programming source code, it is a dependency.
- Realization 4
The classB defines the specification, and the ClassA realizes it.
But , usually , in this case , it is noted like in the Figure 3.
Figure 3 - The notation of the realization
- There are some others. But because I don't understand , those are omitted.
I'm sorry.
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Note.
1: If you need the details , please read the Fig7.15 on the page 32 and the "7.3.53 Usage (from Dependencies)" on the page 131 in the
UML2.0 Sepecification.
2: Properly speaking , there may be associations from the ClassA to the ClassB. But in this case, the arrow of the dependency is not drawn in the class diagram. Because , when there are associations , the class is used ( because we can understand without the arrow of the dependency, it is not drawn.).
3: I wrote "the exception type" , but in the VBA , it is only the ErrOjbect. ... Then , in this case , even if you describe in the class diagram , I think that there are no means.
4: If you need the details , please read the Fig7.15 on the page 32 and the "7.3.45 Realization (from Dependencies)" on the page 124 in the
UML2.0 Sepecification.
Therefore, now , I think the following.
- First of all , I determine the things that I want to inform in the class diagram. For example , when I create the Word document , I determine the things that I want to inform . And this is in the class diagram also.
If I understand without the arrow of the dependency 1, I don't draw.
- When there is already the class diagram , I will fit it.
( The details degree is matched to based class diagram. )
If there are some other rule , I will fit it.
But , this is not abusolute. If a dependency is important, I will draw it.
- When I want to draw the detail class diagram, I will draw many dependencies. In this case , I will divide the class diagram 2. Because it is impossible to inform by one class diagram, I think that it may be divided. If it is still unreadable so that unordered , I will not draw ( or write ) the obvious element ( for example , if the return value or parameter of the operation is written , I can understand without the arrow of the dependency.)
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Note.
1: I wrote "without the arrow of the dependency". And , This is not only the dependency , this is the operation , attribute and so on too.
2: After I divide the class diagram , I will sure do determine the things that I want to inform in the divided class diagram.
The following tables are pages that I referred to create this page.
|
No. |
Linked Website Name |
Description |
Linked date |
|
1 |
OMG
Document -- |
You can download the UML Superstructure Specification, v2.0.
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December 31, 2009 |
I doesn't assume the responsibility of any damage that occurs because of the use of this page.
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Visual Basic® for Applications may represent a VBA.
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UML ,Unified Modeling Language are trademarks of Object Management Group Inc. in the U.S. and other countries.
The UML diagrams in the page are created by SystemDirector Application Modeler UML Editor V2.0 made by NEC Corporation.
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The author of this page and these companies do not have any relationship.
