Project Overview

Expertiza Background

Expertiza is an online platform designed to facilitate peer review and submission of various types of academic work, including articles, codes, and websites. The application allows instructors to add assignments, grade them, and assign students to teams based on their topic preferences. The platform also enables students to provide feedback on each other's work through peer reviews, which can be helpful in improving the quality of their projects. Expertiza is backed by the National Science Foundation.

Problem Statement

The Invitation model and InvitationsController are responsible for managing invitations between users in a team-based assignment system. The system allows a student to invite another student to their team by creating a new Invitation record, which is associated with the inviting and invited students and the assignment they are working on. The invited user can accept, decline, or cancel the invitation, which updates the corresponding Invitation record and may trigger actions such as adding or removing users from teams. The InvitationsController includes methods for creating, accepting, declining, and canceling invitations, as well as checking the status of the user and team before sending or accepting invitations. The system also sends email notifications to invited users when a new invitation is sent. Overall, the Invitation model and InvitationsController are crucial for managing team membership and collaboration in a team-based assignment system. Instructor’s note: There is already a project to merge this controller with the join_team_requests_controller. You should start with the code they have written.

Objectives

1. Write RESTful endpoints of create, show, delete to invitations and approving new invitations, listing pending invitations, creating new invitations, and notifying students about new team formation invite.

2. Develop and implement methods in the InvitationsController that enable the following functionality:Create invitations, Accept invitations, Decline invitations, Cancel invitations, and Check user and team status before sending or accepting invitations.

3. To implement a user-invitation system that allows invited users to accept, decline, or cancel invitations, which will update the corresponding Invitation record and trigger actions such as adding or removing users from teams.

4. Implement an email notification system in the user-invitation system, which sends email notifications to invited users when a new invitation is sent.

5. Return proper status codes and proper validation for RESTful endpoints.

6. Write models and controllers such that they use modern approaches to writing Ruby code, including utilizing language features and adhering to best practices for object-oriented design.

7. Write proper Rspec tests for all APIs, models, controllers.

Development Strategy

We have tried to follow a Test Driven Development approach to implement both the Invitation model and the Invitation Controller. Firstly a failing test case was written and then the code was added such that the test which was failing will pass now.

Also, we have tried to follow the rails philosophy of "Fat models" We have tried to move as much business logic from the controller to the model as possible. This will also help keep the controller code clean and encourage code reusability.

Project Design and Implementation

Use Case Diagram

Class Diagram

Functionality

In this project, we aim to add the following functions:

1. Enable users to create a new team invitation.

2. Enable users to Accept or Reject invitations.

3. Enable users to Retract invitations.

4. Enable users to send email notifications to invited users.

5. Ensure that data is validated properly in all the above APIs.

6. Test cases for all the above.

Screen Shots

Send an invite

File:Dshah6 send invite 3.png

Accept an invite

File:Dshah6 accept 3.png

Reject invite

Retract invite

We retracted invitation of angel and malka and added ofelia

Project Design

Model

W: waiting
A: accepted
R: rejected/declined

filename: invitation.rb
GitHub file Link to invitation.rb

class Invitation < ApplicationRecord
 after_initialize :set_defaults
 ACCEPT_STATUS = 'A'.freeze
 REJECT_STATUS = 'R'.freeze
 WAITING_STATUS = 'W'.freeze
 belongs_to :to_user, class_name: 'User', foreign_key: 'to_id', inverse_of: false
 belongs_to :from_user, class_name: 'User', foreign_key: 'from_id', inverse_of: false
 belongs_to :assignment, class_name: 'Assignment', foreign_key: 'assignment_id'
 validates :reply_status, presence: true, length: { maximum: 1 }
 validates_inclusion_of :reply_status, in: [ACCEPT_STATUS, REJECT_STATUS, WAITING_STATUS], allow_nil: false
 validates :assignment_id, uniqueness: {
   scope: %i[from_id to_id reply_status],
   message: 'You cannot have duplicate invitations'
 }

 validate :to_from_cant_be_same

 # validate if the to_id and from_id are same
 def to_from_cant_be_same
   return unless from_id == to_id
   errors.add(:from_id, 'to and from users should be different')
 end

 # Return a new invitation
 # params = :assignment_id, :to_id, :from_id, :reply_status
 def self.invitation_factory(params)


   Invitation.new(params)
 end

 # check if the user is invited
 def self.invited?(from_id, to_id, assignment_id)
   @invitations_count = Invitation.where(to_id:)
                                  .where(from_id:)
                                  .where(assignment_id:)
                                  .where(reply_status: WAITING_STATUS)
                                  .count
   @invitations_count.positive?
 end

 # send invite email
 def send_invite_email
   InvitationSentMailer.with(invitation: self)
                       .send_invitation_email
                       .deliver_later
 end

 # Remove all invites sent by a user for an assignment.
 def remove_users_sent_invites_for_assignment(user_id, assignment_id); end


 # After a users accepts an invite, the teams_users table needs to be updated.
 # NOTE: Depends on TeamUser model, which is not implemented yet.
 def update_users_topic_after_invite_accept(inviter_user_id, invited_user_id, assignment_id); end


 # This method handles all that needs to be done upon a user accepting an invitation.
 # First the users previous team is deleted if they were the only member of that
 # team and topics that the old team signed up for will be deleted.
 # Then invites the user that accepted the invite sent will be removed.
 # Last the users team entry will be added to the TeamsUser table and their assigned topic is updated
 def accept_invitation(logged_in_user)
   update(reply_status: ACCEPT_STATUS)
 end


 # This method handles all that needs to be done upon an user decline an invitation.
 def decline_invitation(logged_in_user)
   update(reply_status: REJECT_STATUS)
 end


 # This method handles all that need to be done upon an invitation retraction.
 def retract_invitation(logged_in_user)
   destroy
 end

 # This will override the default as_json method in the ApplicationRecord class and specify
 def as_json(options = {})
   super(options.merge({
                         only: %i[id reply_status created_at updated_at],
                         include: {
                           assignment: { only: %i[id name] },
                           from_user: { only: %i[id name fullname email] },
                           to_user: { only: %i[id name fullname email] }
                         }
                       })).tap do |hash|
   end
 end
 def set_defaults
   self.reply_status ||= WAITING_STATUS
 end
end

Helper Methods in Invitation model.

to_from_cant_be_same:

validate if the to_id and from_id are same i.e a users cannot send invitations to themselves.

self.invitation_factory(params):

This helper method will help in creating new Invitation with the given parameters. Custom parameters can be passed to create specific Invitation.

self.invited?(from_id, to_id, assignment_id):

check if the user is invited given the from_id, to_id, and assignment_id. This is a class method to make it more generic and can be used by other classes.

send_invite_email:

This method uses the InvitaionSentMailer to send invitation emails to the invited user.

remove_users_sent_invites_for_assignment(user_id, assignment_id) [ OUT OF SCOPE OF THIS PROJECT ]:

Removes all invites sent by a user for an assignment. This method can be useful

update_users_topic_after_invite_accept(inviter_user_id, invited_user_id, assignment_id) [ OUT OF SCOPE OF THIS PROJECT ]:

After a users accepts an invite, the teams_users table needs to be updated. NOTE: Depends on TeamUser model, which is not implemented yet.

accept_invitation:

This method handles all that needs to be done upon a user accepting an invitation.

decline_invitation:

This method handles all that needs to be done upon an user decline an invitation.

retract_invitation:

This method handles all that need to be done upon an invitation retraction.

as_json:

This will override the default as_json method in the ApplicationRecord class and specify

set_defaults:

This will be used to set default parameters when creating new Invitation.

Changes in models/user.rb
GitHub Link to user.rb file

has_many :invitations

Changes in models/assignment.rb

GitHub Link to assignment.rb file

# add the following relations in the assignment.rb file.

class Assignment < ApplicationRecord
 	has_many :invitations
end

Schema

filename: schema.rb
GitHub Link to scheme.rb file

  create_table "invitations", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
    t.integer "assignment_id"
    t.integer "from_id"
    t.integer "to_id"
    t.string "reply_status", limit: 1
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
    t.index ["assignment_id"], name: "fk_invitation_assignments"
    t.index ["from_id"], name: "fk_invitationfrom_users"
    t.index ["to_id"], name: "fk_invitationto_users"
  end

Controllers

We create a new controller at app/controllers/invitation_controller.rb with following methods: [Implementation of the invitation controller[1]]

REST Route methods

create:

This will create a new invitation record.

index:

This will give a list of all the invitations

show:

This will be used to show a particular invitation with given invitation_id.

update:

This will be used to update the status of the current invitation. Either accepted or rejected

destroy:

This will be used to delete the invitation that is already sent to another participant using particular invite_id.

invitations_for_user_assignment:

This will be used to get all the invitations for a particular assignment for a particular student.

Helper methods

check_team_before_accept [Not in scope of this project]:

This method will check if the team meets the joining requirements when an invitation is accepted.

check_team_before_invitation [Not in scope of this project]:

This method will check if the team meets the joining requirement before sending an invite.

check_participant_before_invitation [Not in scope of this project]:

This method will check if the invited user is a participant in the assignment.

check_user_before_invitation [Not in scope of this project]:

This method will check if the invited user exists.

End point description

create

Description: This route will create a new invitation record with default reply_status: w. w stands for waiting.
REST VERB: POST
Path: /invitations/

Response: 

Success:
Status code: 200

```
{
 {
  "id": 11,
  "reply_status": "W",
  "created_at": "2023-04-20T21:33:29.580Z",
  "updated_at": "2023-04-20T21:33:29.580Z",
  "assignment": {
    "id": 2,
    "name": "oodd program3"
  },
  "from_user": {
    "id": 2,
    "name": "jhon",
    "fullname": "jhon carmen",
    "email": "example1@gmail.com"
  },
  "to_user": {
    "id": 1,
    "name": "katy",
    "fullname": "katy shah",
    "email": "example2@gmail.com"
  }
}
 
```

Failure:
Status code: 422

```
{
  error: @invitation.errors 
}

```

index

Description: Get a list of all the invitations in the database.
REST VERB: GET
Path: /invitations/
Request: NA

Success
Status Code: 200
```
[
  {
    "id": 1,
    "reply_status": "A",
    "created_at": "2023-04-13T17:22:09.805Z",
    "updated_at": "2023-04-19T00:06:33.718Z",
    "assignment": {
      "id": 1,
      "name": "program4"
    },
    "from_user": {
      "id": 2,
      "name": "katy",
      "fullname": "katy kimson",
      "email": "kt@gmail.com"
    },
    "to_user": {
      "id": 1,
      "name": "john",
      "fullname": "john fella",
      "email": "john@gmail.com"
    }
  },
  {
    "id": 2,
    "reply_status": "W",
    "created_at": "2023-04-18T15:52:44.543Z",
    "updated_at": "2023-04-18T15:52:44.543Z",
    "assignment": {
      "id": 1,
      "name": "program4"
    },
    "from_user": {
      "id": 1,
      "name": "john",
      "fullname": "john fella",
      "email": "john@gmail.com"
    },
    "to_user": {
      "id": 3,
      "name": "rebecca",
      "fullname": "rebecca fiat",
      "email": "reb@gmail.com"
    }
  }
]

```

show

Description: Get a particular invite with the invite_id.
REST VERB: GET
Path: /invitations/<invite_id>
Request: NA
Response: 

success
status code: 200
```
{
    "id": 1,
    "reply_status": "A",
    "created_at": "2023-04-13T17:22:09.805Z",
    "updated_at": "2023-04-19T00:06:33.718Z",
    "assignment": {
        "id": 1,
        "name": "program4"
    },
    "from_user": {
        "id": 2,
        "name": "katy",
        "fullname": "katy kimson",
        "email": "kt@gmail.com"
    },
    "to_user": {
        "id": 1,
        "name": "john",
        "fullname": "john fella",
        "email": "john@gmail.com"
    }
}

```

Error
Status code: 404

```
{
    "error": "Couldn't find Invitation with 'id'=1021321"
}
```

update

Description: This route will modify the status of the invitation to be accepted or declined
REST VERB: PATCH
Path: /invitations/<invite_id>/
Request: 
```
{
"reply_status": ["A"/"R"],
}

```
Response: 

Success
Status Code: 200

```
{
    "id": 1,
    "reply_status": "A",
    "created_at": "2023-04-13T17:22:09.805Z",
    "updated_at": "2023-04-19T00:06:33.718Z",
    "assignment": {
        "id": 1,
        "name": "program4"
    },
    "from_user": {
        "id": 2,
        "name": "katy",
        "fullname": "katy kimson",
        "email": "kt@gmail.com"
    },
    "to_user": {
        "id": 1,
        "name": "john",
        "fullname": "john fella",
        "email": "john@gmail.com"
    }
}
```

Error
Status Code: 404/422

```
{
  "error": @invitation.errors
}
```

destroy

Description: Delete the invitation
REST VERB: DELETE
Path: /invitations/<invite_id>
Request: NA
Response: 

Success
Status code: 204 :no_content
Response: NA

Error
Status Code: 404
Response
```

{
  "error": @invitation.errors
}

```

invitations_for_user_assignment

Description: Get the invitations for the user with id: user_id for the given assignment with id: assignment_id.
REST VERB: GET
Path: /invitations/<user_id>/<assingment_id>
Request: NA
Response: 

Success
Status Code: 200 :ok

```
[
    {
        "id": 1,
        "reply_status": "A",
        "created_at": "2023-04-13T17:22:09.805Z",
        "updated_at": "2023-04-19T00:06:33.718Z",
        "assignment": {
            "id": 1,
            "name": "program4"
        },
        "from_user": {
            "id": 2,
            "name": "katy",
            "fullname": "katy kimson",
            "email": "kt@gmail.com"
        },
        "to_user": {
            "id": 1,
            "name": "john",
            "fullname": "john fella",
            "email": "john@gmail.com"
        }
    },
    {
        "id": 2,
        "reply_status": "W",
        "created_at": "2023-04-18T15:52:44.543Z",
        "updated_at": "2023-04-18T15:52:44.543Z",
        "assignment": {
            "id": 1,
            "name": "program4"
        },
        "from_user": {
            "id": 1,
            "name": "john",
            "fullname": "john fella",
            "email": "john@gmail.com"
        },
        "to_user": {
            "id": 1,
            "name": "john",
            "fullname": "john fella",
            "email": "john@gmail.com"
        }
    }
]

```

Error
Status Code: 404 :not_found

```
{
  "error": @invitations.errors
}

```

End point summary

Sr No	Method	Endpoint	Request Body	Description
1	create	POST /invitations/	assignment_id: INT, from_id: INT, to_id: INT, reply_status: CHAR	Create a new invitation record with default reply_status: w, w stands for waiting.
2	index	GET /invitations/		Get a list of all the invitations.
3	show	GET /invitations/<assignment_id>		Get a particular invite with the invite_id.
4	update	PATCH /invitations/<invite_id>/	"reply_status"=["A"/"R"]	Modify the status of the invitation to be accepted or declined.
5	destroy	DELETE /invitations/<invite_id>		Delete the invitation.
6	invitations_for_user_assignment	GET /invitations/<assignment_id>		Get the invitations for the user with id: user_id for the given assignment with id: assignment_id

Testing Plan

We utilized RSpec as the testing framework for our system. We have used factoryBot along with Faker to create model objects for testing. The development process has followed Test Driven Development. The tests for the model and the controller are written in a comprehensive way.

Controller Tests

To run the controller tests:

1. git clone

2. cd reimplementation-back-end/

3. bundle install

4. bundle exec rspec spec/requests/api/v1/invitation_controller_spec.rb

File: invitation_controller_spec.rb

Sr No	Test Description
1	Test to list all Invitations
2	Test to create an invitation with valid parameters
3	Test to create an invitation with invalid 'to' user parameters'
4	Test to create an invitation with invalid 'from' user parameters
5	Test to create an invitation with invalid assignment parameters
6	Test to create an invitation with invalid reply_status parameter
7	Test to create an invitation with same to user and from user parameters'
8	Test to show invitation with valid invitation id
9	Test to show invitation with invalid invitation id
10	Test to accept invite successfully
11	Test to reject invite successfully
12	Test to update invitation with invalid reply_status
13	Test to update status with invalid invitation_id
14	Test to delete invitation with valid invite id
15	Test to delete invitation with invalid invite id
16	Test to show all invitations for the user for an assignment
17	Test to show invitation with invalid user and assignment
18	Test to delete invitation with invalid invite idTest to Show invitation with user and invalid assignment
19	Test to show invitation with invalid user and invalid assignment

Rspec tests screenshot.

Model Tests

To run the model tests: