Use Case Diagram: Social Media System

Actors:

• Registered User
• Administrator
• Guest User
• External Authentication Provider
• Notification Service
• Messaging Server

Use Cases:

User Registration

• Description: The guest user can sign up and create an account.
• Actor(s): Guest User

Login

• Description: The registered user logs in to the system, either through direct login or third-party authentication.
• Actor(s): Registered User, External Authentication Provider

Create/Manage Profile

• Description: The user can update their profile information, including pictures, bio, and visibility settings.
• Actor(s): Registered User

Post Content

• Description: The user can create posts including text, images, or videos.
• Actor(s): Registered User

Like, Comment, and Share

• Description: Users can interact with posts by liking, commenting, and sharing them.
• Actor(s): Registered User

Follow Users

• Description: Users can follow or unfollow other users to see their posts on the feed.
• Actor(s): Registered User

Send Direct Message

• Description: The user can send private messages to other users.
• Actor(s): Registered User

Receive Notifications

• Description: The user will receive notifications about interactions like likes, comments, new followers, or messages.
• Actor(s): Registered User, Notification Service

View Public Content

• Description: Guest users can view publicly available posts or profiles.
• Actor(s): Guest User

Moderate Content

• Description: Administrators can review and remove inappropriate or reported content.
• Actor(s): Administrator

Manage Banned Users

• Description: Administrators can ban or unblock users who violate platform rules.
• Actor(s): Administrator

Authenticate User

• Description: The external authentication provider helps verify user credentials during login.
• Actor(s): External Authentication Provider

Push Notifications

• Description: The notification service sends notifications to users for different events like interactions or updates.
• Actor(s): Notification Service

Real-Time Messaging

• Description: The messaging server handles communication between users in real time.
• Actor(s): Messaging Server

Diagram Overview:

• The Registered User interacts with many use cases: Create/Manage Profile, Post Content, Like/Comment/Share, Follow Users, Send Direct Message, and Receive Notifications.
• The Guest User can only access View Public Content and User Registration.
• The Administrator handles the Moderate Content and Manage Banned Users use cases.
• The External Authentication Provider assists with Authenticate User during the login process.
• The Notification Service is responsible for Push Notifications sent to the user based on certain events.
• The Messaging Server enables Real-Time Messaging for users.