12.05 UML Diagram

#UML #class-diagram #usecase-diagram #unit-3
UML Diagrams are a form of modeling language used within software design

They are used for building and refining software architecture based on user requirements

UML is just the modeling language.

class, sequence, collab, usecase

Class Diagram

• class diagrams have shit like classes and functions in them
• they have information about those functions like parameters and return type of the functions
• they also have class variables on the classes

classDiagram
    class Library {
        -name: String
        -location: String
        +addBook(book: Book)
        +registerMember(member: Member)
    }

    class Book {
        -title: String
        -author: String
        -isbn: String
        -isAvailable: Boolean
        +checkout()
        +returnBook()
    }

    class Member {
        -name: String
        -memberId: String
        +borrowBook(book: Book)
        +returnBook(book: Book)
    }

    class Librarian {
        -employeeId: String
        +manageBooks()
        +assistMember(member: Member)
    }

    Library "1" --> "*" Book
    Library "1" --> "*" Member
    Library "1" --> "*" Librarian
    Member --> Book : borrows >
    Librarian --> Book : manages >

Sequence Diagram

• Shows how objects interact with eachother and the order those interactions occur.
• Processes are represented vertically and interactions are represented horizontally
• interactions contain arrows to show their direction
• interactions are ordered from top to bottom based on their chronological order of execution (just bullshiot)

sequenceDiagram
    participant Member
    participant Librarian
    participant Library
    participant Book

    Member->>Librarian: request to borrow(bookId)
    Librarian->>Library: findBook(bookId)
    Library-->>Librarian: book
    Librarian->>Book: checkout()
    Book-->>Librarian: status updated
    Librarian-->>Member: confirm checkout

Collaboration Diagram

• They are similar to sequence diagram but the focus is on messages passed between objects
• same information is being represented in both ways

sequenceDiagram
    participant Member
    participant Book
    participant Librarian
    participant Library

    Note over Member,Librarian: Collaboration to borrow a book
    Member->>Librarian: Request book
    Librarian->>Library: Lookup book
    Library-->>Librarian: Provide book
    Librarian->>Book: checkout()
    Book-->>Librarian: confirm
    Librarian-->>Member: Hand over book

Use Case Diagram

• STICK MAN LES GO
• shows a graphic overview of the actors involved in a system and how different functions are needed to interact between those actors