Use Cases Diagram

## Use case: Register

• Short description: Registration (new user).
• Players: Client and DB.
• Prerequisites: Valid email and password.
• Basic flow:

• The user selects the register button.
• The user has chosen to register via email.
• Filling in the required information in the text fields.
• Verification link sent to email.
• The user entered the link.

• Flow in exceptional mode: In case there is an error in filling in the information, a message appears telling the user the error.
• Post-condition: There is a new user.

## Use case: login

• Short description: Entrance.
• Players: Client and DB.
• Prerequisites: Account already exists.
• Basic flow:

• The user selects the login button.
• Fill in the username and password fields.
• Checks if the user exists in the database.
• The main screen appears. Alternate flow:
• The user selects the login button.
• Click on "I forget my password".
• Fills in his username.
• The app checks how the user has registered (via email or phone number).
• The app sends an email to the user to recover his password.

• Flow in exceptional mode: In case there is an error in filling in the information, a pop-up message appears that tells the user the error (incorrect username / password).
• Post-condition: The user receives appropriate permissions to view the application.

## Use Case: Upload Video

• Short description: Upload a video to the course website that belongs to it.
• Players: Client and DB.
• Prerequisites: An existing account and an existing course.
• Basic flow:

• The user enters the course he wants to put the video in.
• The user clicks the Upload video button
• The user fills in the required details like the title of the video
• The user selects the order in which the video appears within the course video list.

• Flow in exceptional mode: In case there is an error, a message appears telling the user the error.
• Post-condition: The video will appear in the list.