Table of content

• Table of content
• About
• Entity Relationship Diagram
• Modeling Data - Relationships Between The 4 Models
• Mongoose Schemas
• API
• Use it locally
  • Using docker
  • Detailed steps on how to run the application locally in Linux
  • Detailed steps on how to run the application locally in Windows
• How It Looks

About

This is a question-and-answer social network website where users are able to:

• Create and follow different topics
• Ask questions in these topics
• Answer questions and like/dislike answers.
• Track other users in the website to see what questions someone asked, what answers he/she gave, which topics they follow, …etc

Entity Relationship Diagram

Here is the ERD for this app:

Modeling Data - Relationships Between The 4 Models

A user has many topics (create)\
A topic belongs to one user \
=> one to many

A user has many questions (ask) \
A question belongs to one user \
=> one to many

A user has many answers (answer) \
An answer belongs to one user \
=> one to many

A topic has many questions \
A question belongs to one topic \
=> one to many

A question has many answers \
An answer belongs to one question \
=> one to many

A user can follow many topics (follow) \
A topic has many followers \
=> many to many

An answer has many users who like it \
A user can like many answers \
=> many to many

Mongoose Schemas

I use two way (parent & child) referencing for all relationships:

User{
    _id             : ObjectId
    firstName       : String
    lastName        : String
    email           : String
    password        : String
    imageName       : String
    registrationDate: Date
    topics          : Topic[]       //we store the topics ids
    questions       : Question[]    //same
    answers         : Answer[]
    topicsFollowed  : Topic[]
    answersLiked    : Answer[]
}

Topic{
    _id             : ObjectId
    name            : String
    description     : String
    imageName       : String
    creationDate    : Date
    user            : User
    questions       : Question[]
    usersFollowers  : User[]
}

Question{
    _id             : ObjectId
    content         : String
    creationDate    : Date
    topic           : Topic
    user            : User
    answers         : Answer[]
}

Answers{
    _id             : ObjectId
    content         : String
    creationDate    : Date
    user            : User
    question        : Question
    usersWhoLike    : User[]
}

API

GET    /users
GET    /users/:id
GET    /users/:id/:content (content == questions | answers | topics | topics-followed)
GET    /users/register
GET    /users/login
POST   /users/register
POST   /users/login
DELETE /users/logout

GET    /topics
GET    /topics/:id
GET    /topics/create
POST   /topics/create
GET    /topics/:id/question
POST   /topics/:id/question
DELETE /topics/:id              //NIY
PATCH  /topics/:id              //NIY
POST   /topics/follow-infollow  //NIY

GET    /questions/:id
GET    /questions/:id/answer
POST   /questions/:id/answer
DELETE /questions/:id           //NIY
PATH   /questions/:id           //NIY

POST   /answers/like-unlike
GET    /answers/:id             //NIY
DELETE /answers/:id             //NIY
PATH   /answers/:id             //NIY

(NIY <=> Not Implemented Yet )

Use it locally

Using docker

• Clone the project & unzip it

• Open the project in the terminal

• Run

    docker compose up

  if you watch the logs you may see this error:

  

  This is related to EOL (end of line) difference between Windows & Linux systems. If you are cloning the project in Windows Machine, change the EOL for the file mongodb-database/import-data.sh to be LF (\n).

  In VSCODE you can do this easily by looking at the bottom menu when the file is opened.

  

• Open a browser & head to http://localhost:8082 to see the content of the database (social_network_db)

  you should see 4 collections (users, topics, quetions, answers), each one with some data in it.

  If its not the case, refer to previous step (error may be related to EOL for the mongodb-database/import-data.sh).

• Visit http://localhost:3001 to see the app running

• You can log in to the website with a bunch of existing accounts:

  • alae@gmail.com/ alae
  • hamza@gmail.com/hamza

  • farid@gmail.com/farid

    or just create one for you instead.

Detailed steps on how to run the application locally in Linux

• To install Nodejs, visit this link https://github.com/nodesource/distributions/blob/master/README.md

  Go to Debian and Ubuntu based distributions section and find the wanted Nodejs version and run the commands. For example, if you want to install Nodejs version 12, you will run:

    # Using Ubuntu
    curl -fsSL https://deb.nodesource.com/setup_12.x | sudo -E bash -
    sudo apt-get install -y nodejs

• Install MongoDB database via

    sudo apt install mongodb

• Start the MongoDB service via:

    sudo service mongodb start

• You can check if MongoDB service is active using:

    sudo systemctl status mongodb

• Now its time to create the database and its collections, to do this, open the mongo shell using:

    mongo

• From the mongo shell, run these commands one after another:

    use social_network_db
    db.createCollection('users')
    db.createCollection('questions')
    db.createCollection('answers')
    db.createCollection('topics')

• Download the project into the filesystem

• Unzip it

• Now we need to import the data into the mongodb database collections

• Open a terminal & go to the downloaded project’s directory & run the following commands one after another

    mongoimport --db social_network_db --collection users --drop --file ./mongodb-database/users.json --jsonArray

    mongoimport --db social_network_db --collection questions --drop --file ./mongodb-database/questions.json --jsonArray

    mongoimport --db social_network_db --collection answers --drop --file ./mongodb-database/answers.json --jsonArray

    mongoimport --db social_network_db --collection topics --drop --file ./mongodb-database/topics.json --jsonArray

• Always from the project’s directory, run

    npm install

  to install npm dependencies

• ALways from the project’s directory, run:

    npm run startdev

  To run the app

• go to http://locahost:3000

• You can log in to the website with a bunch of existing accounts (email/password):

  • alae@gmail.com / alae
  • hamza@gmail.com / hamza
  • farid@gmail.com / farid

Detailed steps on how to run the application locally in Windows

• MongoDB/Nodejs Download & install

  • To download Nodejs for windows, follow the link https://nodejs.org/en/download/ and use the installer and follow the installation steps

  • Download MongoDB for Windows from the link https://www.mongodb.com/try/download/community

  • Run the .msi file to run the installation wizard (leave everything as default.. default is BEST)

  • Create this directory structure C:\data\db

  • Go to MongoDB installation folder and somewhere there in the directory structure you will find a bin folder, add it to the PATH env variable .

  • Now we need to download The MongoDB Database Tools (colleciton of command-line utilities for working with MongoDB), to do this head to https://www.mongodb.com/try/download/database-tools?tck=docs_databasetools and download the zip file

  • Extract the zip under C:\ drive

  • under this zip, you will find a bin folder, add it to the PATH env variable

• Running MongoDB server and importing the data into the database

  • Open cmd and run the MongoDB deamon using this command:

      .\mongod.exe

  • Now we need to create the database and its collections, open cmd run the MongoDB client

      .\mongo.exe

  • From the mongo shell that appears, run the following commands one after another

      use social_network_db
      db.createCollection('users')
      db.createCollection('questions')
      db.createCollection('answers')
      db.createCollection('topics')

  • The rest of the steps to import the data and run the app are the same as in Linux

How It Looks