![]() ![]() If the studentNumber() was not automatically sent, it would mean that the student would have to enter his or her studentNumber() again, which would not be a satisfactory user interface because it involves redundant keying. This form contains the studentNumber(), sent along with the studentWebPage, and is used to send a message to the :Section class to obtain the section grade. When the user clicks this button, it sends a Web form to the :View Student Interface Controller. At the bottom of the page is a nextButton that the student clicks to view courses. The studentWebPage is returned to the :View Student User Interface, which displays the information in the Web browser. The :View Student Interface Controller sends a getStudent( ) message to the :Student class, which reads a database table and proceeds to return the studentData. This class is responsible for the coordination of sending messages and receiving returned information from all the other classes. When the student clicks the Submit button, the Web form is passed to a :View Student Interface Controller. This is a Web form that obtains the student’s user ID and password. The student is shown on the left as an actor, and he or she provides a userLogon to the :View Student User Interface class. In the diagram, :View Student User Interface is an example of an interface class :Student, :Section, and :Course are examples of entity classes and :View Student Interface Controller and :Calculate Grade Point Average are control classes.Ī sequence diagram for using two Web pages: one for student information, one for course information. Figure below is an example illustrating a sequence diagram representing a student viewing his or her personal and course information. The different types of classes are often used when working in the systems design phase. They allow the analyst freedom to play with the design to optimize reusability. These are called stereotypes, an extension to UML, which are special symbols that may be used during analysis, but are often used when performing object-oriented design. To obtain a greater degree of reuse, consider moving methods from a control class to an entity class.Ĭlasses may also be represented using special symbols for entity, boundary (or interface), and control classes.Realize that the sequence diagram may be modified again when doing detailed design, such as creating additional Web pages or control classes (one for each Web form submitted).Examine the use case to see what entity classes are present.Look for that control class and include it in the sequence diagram. Ensure each use case has one control class, although more may be created during the detailed design. ![]() Create prototype Web pages for all human interfaces.Each actor should have his or her own interface class. Define one or more interface classes for each actor.There may be an additional actor on the right side of the diagram, such as a credit card company or bank. This will be a stick figure from the use case diagram. Include the actor from the use case diagram in the enhanced sequence diagram.The following steps are a useful approach to enhancing a sequence diagram: Sequence diagrams in particular can be overbearing if an analyst doesn’t have a systematic approach to drawing them. Once the class diagram is drawn, it may be desirable to go back to the sequence diagram and include special symbols for each of the different types of classes introduced in the last section. ![]()
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