CSC/ECE 517 Fall 2024 - E2484. Reimplement participants controller.rb

About Expertiza

Expertiza is an open source project based on Ruby on Rails framework. Expertiza allows the instructor to create new assignments and customize new or existing assignments. It also allows the instructor to create a list of topics the students can sign up for. Students can form teams in Expertiza to work on various projects and assignments. Students can also peer review other students' submissions. Expertiza supports submission across various document types, including the URLs and wiki pages.

Introduction

This project aims to reimplement the participants_controller.rb and participants_helper.rb in the new Expertiza system. The participants_controller.rb manages participants within assignments, and this reimplementation focuses on streamlining its methods, eliminating redundancy, and enhancing code readability and maintainability.

Requirements

Implement participants_controller.rb Methods: Fully implement each controller method with the same functionality as the current controller.

Import from participants_helper.rb : Integrate relevant helper methods to streamline functionality and remove redundancy.

API Creation: Expose API endpoints for all necessary methods to enable seamless access and integration from the frontend. Ensure that each endpoint follows best practices for RESTful API design, including proper error handling and secure data access.

Testing with rswag: Create test cases for all methods, focusing on edge cases, and generate rswag documentation.

Swagger UI Video Documentation: Record a video walkthrough of API endpoints in Swagger UI, showcasing each method’s functionality.

Existing Issues

Reimplement participants_controller.rb while addressing the following:

Refactor code to comply with the Open-Closed Principle and the Single Responsibility Principle.

Introduce dependency injection where necessary.

Reduce excessive conditional statements.

Include sufficient code tests to verify functionality.

Enhance comments to better explain each method's functionality, purpose, and rationale for keeping or modifying particular aspects of the code.

Provide a more detailed explanation of design choices and refactoring steps.

Design / Proposed Solution

Controller Diagram

API Calls

#	Method	Endpoint	Description
1	index	GET /participants	Return a list of participants
2	show	GET /participants/:id	Return a specified participant
3	inherit	GET /participants/inherit	Copy all participants from a course to an assignment
4	bequeath	GET /participants/bequeath	Copy all participants from an assignment to a course
5	create	POST /participants	Create a participant
6	update_authorization	PATCH /participants/:id/authorization	Update the permissions of a participant
7	update_handle	PATCH /participants/:id/handle	Update the handle of a participant
8	destroy	DELETE /participants/:id	Delete a specified participant

It is worth mentioning that the view_copyright_grants method from the old implementation will not be brought forward as it was incorrectly implemented.

Helper Method(s)

The methods in participants_helper.rb are outdated and do not impact any functionality in participants_controller.rb. Most of these methods pertain to retrieving user data and managing permissions—tasks that no longer require separate methods due to improved associations and centralized authorization management.

The Participant model is associated with the User model through a belongs_to relationship. This association allows user data to be accessed directly, eliminating the need for many of the methods in the old implementation that manually handled such data retrieval.

In addition, authorization_helper.rb centralizes and manages all aspects of permissions and access control. This significantly simplifies the implementation, rendering much of the legacy logic redundant.

As a result, the methods in participants_helper.rb will not be carried forward to the new implementation. However, one method from the old Expertiza participants_controller.rb implementation remains useful and will be retained:

#	Method	Description
1	participant_params	Permitted parameters for creating or updating a Participant object

Pattern(s)

Facade: "A simplified interface that performs many other actions behind the scenes."
The participants_controller.rb uses the Facade Design Pattern to streamline interactions with the Expertiza backend, abstracting away complex logic and data handling tasks into a simplified API layer. A lot of calls to various services, objects, and features are abstracted, providing a unified, cohesive interface. By centralizing these calls, the controller can reduce dependencies on specific backend structures, making it easier for the front end to perform actions with minimal knowledge of what is going on in the backend, enhancing the maintainability and scalability of our codebase. Some such examples would be to call all the participants of a specific assignment, or pulling information about the course from a participant. Things that would otherwise complicate the front end due to the need to hunt through the backend for information that they need can be abstracted away into the facade interface. The current implementation already employs the facade pattern by its nature, but we will improve it by specifically targeting features of the facade design pattern.

SOLID Principle(s)

Open and Closed Principle: "Software entities should be open for extension, but closed for modification."
Currently, the code directly checks the type of curr_object to determine whether it’s an Assignment or Course, which can make it challenging to extend or modify. To address this, we will implement polymorphism by moving participant-related logic into the respective classes (Assignment, Course, etc.). Each class will define its own behavior for handling participants by overriding a common interface or inheriting from a shared base class. For example, A ParticipantHelper file will define methods like add_user_to_course/assignment, store item, participant_permissions, and numerous other non-idiomatic methods that go against the model view controller design pattern. Method operations that implement business logic, such as the methods listed before, should generally not be the responsibility of the controller.

Single Responsibility Principle: "A class should only have one responsibility and should never have more than one reason to change."
The current implementation of the participant controller mixes many responsibilities, such as authorization, handling different object types, and managing participants. We plan to use the Single Responsibility Principle to delegate each responsibility to separate classes and ensure each class has a single responsibility, with the participant controller as their coordinator. For instance, we can create an AuthorizationService Class that handles all the authorizations and permissions logic. Furthermore, we could also create a TeamService for team-related operations. By making these modifications, we reduce the controller’s responsibilities, improving our code’s readability and reusability. Lastly, the frontend developers will have predictable API behavior and consistent responses when our code adheres to the Single Responsibility Principle.

Implementation

Import from participants_helper.rb

Refer to the Helper Methods section

Testing with rswag

Refer to the Testing Plan section

Testing Plan

rswag
We will use rswag to test and document our project’s API endpoints. Rswag integrates RSpec testing with Swagger, allowing us to define test cases in RSpec to validate functionality while automatically generating interactive Swagger documentation. This documentation, accessible through Swagger UI, provides developers and stakeholders with a user-friendly way to explore and interact with our API endpoints.

Tests

Test ID	Test Description
1	Test 'index' with valid model (Assignment) and ID - Should list participants
2	Test 'index' with invalid model (Assignment) and ID - Should return an error message
3	Test 'show' with valid participant ID - Should return the specified participant details
4	Test 'show' with invalid participant ID - Should return participant not found
5	Test 'inherit' with valid assignment ID but no course participants - Should display a message indicating no participants were found to inherit
6	Test 'inherit' with invalid assignment ID - Should return assignment not found message
7	Test 'inherit' with valid assignment ID and course with participants - Should copy participants from course to assignment
8	Test 'bequeath' with valid assignment ID with no assignment participants - Should display a message indicating no participants were found
9	Test 'bequeath' with invalid assignment ID - Should return assignment not found message
10	Test 'bequeath' with valid assignment ID and course with participants - Should copy participants from assignment to course
11	Test 'create' with valid user detail - Should successfully create a new participant
12	Test 'create' with duplicate user information - Should return an error message indicating that the participant already exists
13	Test 'update_authorization' with valid participant ID and permissions - Should update participant’s permissions successfully
14	Test `update_authorization` with invalid participant ID - Should return not found message
15	Test 'update_handle' with valid participant ID and unique handle - Should successfully update
16	Test 'update_handle' with duplicate handle - Should return an error message indicating handle is in use
17	Test 'destroy' with valid participant ID - Should delete the specified participant
18	Test 'destroy' with invalid participant ID - Should return participant not found message

Team

Mentor

• Jay Patel <jhpatel9@ncsu.edu>

Students

• Pierce Whelan <pwwhelan@ncsu.edu>

• Calvin Jiang <crjiang@ncsu.edu>

• Hechun Zhang <hzhang56@ncsu.edu>

Relevant Links

Pull Request [1]
GitHub Repository [2]
GitHub Project Board [3]
participants_controller.rb in Old Expertiza [4]
participants_helper.rb in Old Expertiza [5]