Shows how the business-scoped objects collaborate with each other through use-case specificationShows the view inside the business process
Sequence Diagram:
Is a type of interaction schema Schema represents the interactions over time between objects in a use case. Is a dynamic model that shows the clear order of communication messages between objects. self-emphasizes the chronological order of operations relative to a set of objects, so it is useful to understand real-time details for use cases, especially complex ones. Sequence diagrams can describe all possible scenarios of a uc. However, the analyst often develops a set of sequence diagrams, where each one illustrates a scenario. Can be used in the analysis or design phase. However, the design phase specifies the implementation, which usually includes either a database object or a user interface element.
Viewing: What is a sequence diagram
Components in the sequence diagram;
Actor: Human or non-human. Participate in the process of sending and receiving messagesObject: Participating in the process of sending or receiving messages Object lifeline: Represents the life cycle of the object during the interaction. If X occurs on the lifepath, the object has stopped interacting.Execution occurrence: Indicates when an object sends or receives a message. Placed along the object’s lifeline.Message:Represents information from one object to another. On message naming methodConditional message(guard message):Write precondition, method End of object destruction (object destruction)
Boundary : interface boundary class. They can be forms, reports that interface with hardware such as printers.
Entity: Entity class. Is to store information that will be written to external memory. Find them in the interactive chart event. Usually a data table must be created for this class. Each attribute in the entity is usually a field in the database.
Control: responsible for coordinating the activities of other classes. Usually each uc has its own control class. It does not perform any business functions. Other layers of control: security-related and database-related controls
This looks like MVC
2. Message types and action types
Synchronous Call: This is the type of call that represents the operation of sending a message and suspending execution for a while. For example, the user sends a search message and waits for the result. It is denoted by the closing arrow sign
Web Client searches Online Bookshop and waits for results.
Asynchronous Call: This is the type of call that represents the message sending operation and executes immediately without waiting for the return value. It is indicated by an open arrow. For example, the service sends a message to the activity, it will be activated immediately without waiting
Service starts Task and proceeds in parallel without waiting.
See also: What is Hyperlink – How to Create Hyperlink
Create Message: Create Message it sends to the object’s lifeline to create itself. Denoted as a finished stroke and pointed directly at the subject’s head
Online Bookshop creates Account.
Delete Message: Deletes the message it was sent to terminate the object’s life. Denoted with an X
Online Bookshop terminates Account.
Reply Message: Replying to a message is understood as sending a message and waiting for the result to be returned. It is denoted by a 2-way arrow
Web Client searches Online Bookshop and waits for results to be returned.
Lost Message: Lost event is a message where the send events are known but no received events. It is interpreted as the message never reaching its destination. Semantics are accents, recevice Event is absent. Lost message is shown by red circle
Web Client sent search message which was lost.
See also: What is a Predicate – Structure of Predicate
Found Message: different from losing a message that doesn’t know the destination event but knows the send event. Finding the message is knowing the destination event but not the sending event.
