Group 140 CSC207 project: Q/A forum

Group members (alphabetical order by last name):

• Chihan Cui (HermesCui)
• Qianjun Huang (cang-xue)
• Liwei Yang (Blair Yang)
• Jiawei Yu (JY3150)
• Gangquan Zhang (jasongangquanzhang)
• Xiling Zhao (Teinble)
• Jiajie Zhu (Christinjiajie)
• Yuyang Zhao (NerverSoGoodStart) (Dropped)

Delivery details

This ia a link to our presentation file.

Package Organization

Our code splitted the code into several compartments (packages), by clean architecture, being:

• Package entities contains all entity level classes
• Package database contains all database-related classes
• Package use_cases contains all use case level classes
• Package controllers contains all controller classes
• Package presenter contains all presenter classes
• Package UI contains all UI level classes
• Package Exception contains all exceptions
• Package base contains Main class

Testing details

Our code has implemented the following test suites:

- CourseUsecaseInteractorTest
- UserUsecaseInteractorTest
- ReportUsecaseInteractorTest

Use of GitHub Features

Issues

• We used issues along with pull requests.
• Issues are addressed during discuss, and are resolved after suscessful implementation.
• We also used issues to assign tasks to team members.

Pull Request

• We use pull request to discuss and determine whether the code is in good manner and should be merged into Main.
• We also used it to perform code review to ensure code quality.

Auto Grading

• We used auto-grading to run the tests to ensure that our code is bug-free.

Design patterns

We used the following design patterns in our project.

Observer pattern

Add ActionListener and MouseListener to the UI. When the user clicks the button, our program would use the corresponding controller to call the functions related to that action. For example, in LoginForm, when we click Login, it will call UserController loginUser method without calling any other methods besides what methods are used in the loginUser.

Dependency injection

All of our posts are stored in some courses. But when we add a post to a course, we do not pass in relevant information and create a new post is inside of the course; rather, we pass in a post directly. This is also exhibited in posts and comments. Additionally, in the database gateway, we need two dataHandlers to create a gateway, instead of creating those dataHandlers inside this gateway, we create them in Main class and inject them into the gateway.

Simple Factory Pattern (not used)

Since we have many report types, it makes more sense if we could have a Report factory responsible for creating various reports. We could use a simple factory pattern here to implement this in the future.

Clean Architecture

• Our code follows a strict MVC Clean architecture, as mentioned in our slides.

SOLID

• Single Responsibility Principle:
  Every class in our project has only one responsibility. Every non-attributive data
• Open and Closed Principle:
  Our project align with the principle, as the program is easily modifiable.
• Liskov Substitution Principle:
  Our subclasses do not alter the behavior of the general inherited behavior. Therefore, we can safely substitute objects of the super classes by the subclasses.
• Interface Segregation Principle:
  We have specific interface for each task. The interfaces are small, concise.
• Dependency Inversion Principle:
  As long as the interface methods are implement correctly, our program runs without error.

Introduction

YOU NEED TO DOWNLOAD THE JAVX.MAIL package.

1. Entities

1.1 User.java

User.java is a class that is used to store the data of each individual user/administrator of the forum. It implements the Serializable interface for serialization.

The user object has the following attributes:

• username
• userid
• password
• email

The entity provides interfaces for other functions to modify the username, password, and email. The userid, however, is immutable once registration.

1.2 Course.java

Course.java is a class that is used to store the data of each specific course registrated on the forum.
The course object has the following attributes:

• name
• courseCode
• description
• instructors
• semester
• posts

Most attributes for the course objects, once created, are immutable. The object only provides two functions to add/remove students.

1.3 Post.java

Post.java is a class that is used to store the data of the posts in the forum.
The posts has the following attributes:

• topic
• texts
• comments
• user
• likedUser
• unlikedUser

The post object, once created, are modifiable, and can be commented by other user objects.
Some attributes, however, like the user who posted this thread, is immutable and viewable to everyone.

1.4 Comment.java

Comment.java is a class that used to store the data of each comment to a post.
The posts has the following attributes.

• texts
• comments
• user

The comment object is very similar to a post. However, it must be attached to a post or another comment.

1.5 Report.java

Comment.java is a class that used to store the data of a report of a problem in a forum to be viewed and resolved by the administrator.
The posts has the following attributes.

• type
• content
• user

All of the information of the Report object, once created, are immutable.

2. Use cases

2.1 Course use case

Course contains all relevant posts.

2.2 User use case

User can be registered with account name, password and email but not duplicate with other users.

There is verified_email feature, which can auto sent a random code email to the user. The verified code serves as the Random method to protect user accounts.

2.3 Post use case

Uses can post a Post under a course, and Post can contain the numbers of like and unlike, so that user can judge what the best relevant post is.

2.4 Report use case

Administrator can send a report to modify some issue in the software.

3. Database

3.1 Data storage

We used three classes to handle the data, being DatabaseDataHandler, RuntimeDataHandler, and DatabaseGateway.

The use cases andcontrollers interacts with DatabaseGataway to set, get, and edit the (non-attributive) data.

DatabaseGataway implements three data interfaces, being CourseDataInterface, UserDataInterface, ReportDataInterface. It has the following methods that could be called for data handling:

• getAllUsers(), getAllCourses(), getAllReports()
  Which fetches and returns all of the above data from the database.
• getUser(), getCourse(), getPost()
  Which gets the corresponding user, course, and post from their username, code, and title, respectively, in O(1).
• addUser, addReport, addCourse
• deleteUser, `delete

Use of data structure

The run-time data are stored in the RuntimeDataHandler, in the following way:

• ArrayList<User> users
• ArrayList<Course> courses
• ArrayList<Report> reports

The actual objects are stored in these ArrayLists. Furthermore, we made use of Hashmaps to achieve a better time-complexity, and look up.

• Hashmap name2User
• Hashmap email2User
• Hashmap code2Course
• Hashmap type2Report

Using these Hashmaps, our database provides O(1) complexity for searching and fetching.

Serialization

We serialized the data as a single object called Hashmap<Integer, Object> Info. The hashmap has the following structure.

key	value	type	Serializable object	Non-native Attributes
1	all users	ArrayList<User>	User	null
2	all courses	ArrayList<Course>	Course	null
3	all reports	ArrayList<Report>	Report	user, course, Arraylist<Comments>

4. Controllers

4.1 CourseController

CourseController can get the judgement from Course UseCase and return different integers to UI. For example, there is three states in removeInstructor. The method will call course UseCase to judge the exception.

• If return -1, it means not found the instructor in the courss.
• If return 1, it means successfully remove the instructor.

4.2 PostController

PostController can get the judgement from Post UseCase and return different integers to UI. For example, there is three states in editPost. The method will call Post UseCase to judge the exception.

• If return -1, it means not found the Post in the course
• If return 1, it means successfully edit the instructor.

4.3 ReportController

ReportController can get the judgement from Report UseCase and return different integers to UI.

4.4 UserController

UserController can get the judgement from User UseCase and return different integers to UI. For example, there is three states in registerUser. The method will call User UseCase to judge the exception. If return -6, which means the message contains email, otherwise return -1.

• if return -2, which means password is not correct.
• if return -3, which means is the error email format.
• if return -4, which means Wrong re-entered password !
• if return -5, which means wrong verification number.
• if return 1, which means successfully register.