Fully functional ECOMMERCE API USING GIN FRAMEWORK AND MONGODB

-----Initial Release v2.30 ⚠️Not tested the efficiency

project structure

• Ecommerce 📁
  • controllers 📁
    • controllers.go📝
  • database📁
    • database.go📝
  • middleware📁
    • middleware.go📝
  • models📁
    • models.go📝
  • routes📁
    • routes.go📝
  • tokens📁
    • tokengen.go📝
  • go.sum 📝
  • main.go📝

clone this repo and change into the directory ecommerce-main*** make sure go is installed in your system Run

# Start the mongodb container for local development
docker-compose up -d
go run main.go

Using Mongodb for small scale ecommerce industry is not a good idea instead use redis or mysql

API FUNCTIONALITY CURRENTLY ADDED?

• Signup 🔒
• Login 🔒
• Product listing General View 👀
• Adding the products to DB
• Sorting the products from DB using regex 👀
• Adding the products to cart 🛒
• Removing the Product from cart🛒
• Viewing the items in cart with total price🛒💰
• Adding the Home Address 🏠
• Adding the Work Address 🏢
• Editing the Address ✂️
• Deleting the Adress 🗑️
• Checkout the Items from Cart
• Buy Now products💰

future implementations?

• Pagination 1>>2>>3
• Admin Part
• OAuth 2
• etc***

Code At glance in Database(database.go)

first we need to define the database , make sure the mongodb installed in your system. The important thing we have to remember is we need to create a database with two collections , Two collections that for storing the user informations and the other for storing the product informations.We must have to configure the url and port of mongodb configured in your system

// code example of url and port in databasetup.go
mongo.NewClient(options.Client().ApplyURI("mongodb://localhost:27017")) --port and url
// code example of defining collection name
var collection *mongo.Collection = client.Database("Ecommerce").Collection(CollectionName)

like to know more about configurations visit: https://www.mongodb.com/blog/post/quick-start-golang-mongodb-starting-and-setup

Code At glance in models.go

This part defines us how should our database looks like, I think its not about programming skills, but if you have creativity and basic syntax ideas and have some ability to defines struct from creativity 90% of work completed.Before Jumping into other codes we should have a rough idea about our plan so its better to lookup into models .

• We have to define a product first , having a unique id , name and price

type Product struct {
  Product_ID   primitive.ObjectID `bson:"_id"`
  Product_Name *string            `json:"product_name"`
  Price        *uint64            `json:"price"`
  Rating       *uint8             `json:"rating"`
  Image        *string            `json:"image"`
}

• We have to define an slice of array products where a user can store individual products

type ProductUser struct {
  Product_ID   primitive.ObjectID `bson:"_id"`
  Product_Name *string            `json:"product_name" bson:"product_name"`
  Price        int                `json:"price"  bson:"price"`
  Rating       *uint              `json:"rating" bson:"rating"`
  Image        *string            `json:"image"  bson:"image"`
}

• The next struct we have to define the Address

type Address struct {
  Address_id primitive.ObjectID `bson:"_id"`
  House      *string            `json:"house_name" bson:"house_name"`
  Street     *string            `json:"street_name" bson:"street_name"`
  City       *string            `json:"city_name" bson:"city_name"`
  Pincode    *string            `json:"pin_code" bson:"pin_code"`
}

• If the user has ordered something the struct look like the one in below, having an embedded struct inside a struct , here we define the ProductUser as a slice(A person can buy more than one product right?) and a payement struct to define Cash on delivery or digital payement

type Order struct {
  Order_ID       primitive.ObjectID `bson:"_id"`
  Order_Cart     []ProductUser      `json:"order_list"  bson:"order_list"`
  Orderered_At   time.Time          `json:"ordered_on"  bson:"ordered_on"`
  Price          int                `json:"total_price" bson:"total_price"`
  Discount       *int               `json:"discount"    bson:"discount"`
  Payment_Method Payment            `json:"payment_method" bson:"payment_method"`
}

The Payement struct is something look like this

type Payment struct {
  Digital bool `json:"digital" bson:"digital"`
  COD     bool `json:"cod"     bson:"cod"`
}

we can define those structs as the simple fields or blocks (genrally known as documents and subdocuments in mongodb)in the user databse or the user struct

• Finally in the user struct we are going to embedd the simple structs .The new fields in struct are ID, Name ,Email, Token etc

type User struct {
  ID              primitive.ObjectID `json:"_id" bson:"_id"`
  First_Name      *string            `json:"first_name" validate:"required,min=2,max=30"`
  Last_Name       *string            `json:"last_name"  validate:"required,min=2,max=30"`
  Password        *string `json:"password" validate:"required,min=6"`
  Email           *string `json:"email" validate:"email,required"`
  Phone           *string `json:"phone" validate:"required"`
  Token           *string `json:"token"`
  Refresh_Token   *string `josn:"refresh_token"`
  Created_At      time.Time `json:"created_at"`
  Updated_At      time.Time `json:"updtaed_at"`
  User_ID         string `json:"user_id"`
  UserCart        []ProductUser `json:"usercart" bson:"usercart"`
  Address_Details []Address `json:"address" bson:"address"`
  Order_Status    []Order `json:"orders" bson:"orders"`
}

Code At Glance in controllers.go

This file mainly describes about the token authentication process . We have used the JWT authentication from dgrijalwa but now the repository has changed . I have used the same implemtaion for signup and login from https://dev.to/joojodontoh/build-user-authentication-in-golang-with-jwt-and-mongodb-2igd , this blog is clear and precise about jwt auhentication rather than my explanation here.

There is an important thing we have to remember when defining array struct the mongodb converts the array to a nil in document field

So to overcome this problem we make an empty array in signup function like this,whever a user calls the signup function it initialise the documents to empty array

user.UserCart  =   make([]models.ProductUser, 0)
user.Address_Details = make([]models.Address, 0)
user.Order_Status = make([]models.Order, 0)

• SIGNUP FUNCTION API CALL (POST REQUEST)

http://localhost:8000/users/signup

{
  "first_name": "Joseph",
  "last_name": "Hermis",
  "email": "[email protected]", // Use @example.com for email because that is it's purpose. See https://www.rfc-editor.org/rfc/rfc6761.html and https://www.rfc-editor.org/rfc/rfc2606.html
  "password": "unlucky",
  "phone": "+1558426655"
}

Response :"Successfully Signed Up!!"

• LOGIN FUNCTION API CALL (POST REQUEST)

  http://localhost:8000/users/login

{
  "email": "[email protected]",
  "password": "unlucky"
}

response will be like this

{
  "_id": "***********************",
  "first_name": "joseph",
  "last_name": "hermis",
  "password": "$2a$14$UIYjkTfnFnhg4qhIfhtYnuK9qsBQifPKgu/WPZAYBaaN17j0eTQZa",
  "email": "[email protected]",
  "phone": "+1558921455",
  "token": "eyJc0Bwcm90b25vbWFpbC5jb20iLCJGaXJzdF9OYW1lIjoiam9zZXBoIiwiTGFzdF9OYW1lIjoiaGVybWlzIiwiVWlkIjoiNjE2MTRmNTM5ZjI5YmU5NDJiZDlkZjhlIiwiZXhwIjoxNjMzODUzNjUxfQ.NbcpVtPLJJqRF44OLwoanynoejsjdJb5_v2qB41SmB8",
  "Refresh_Token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJFbWFpbCI6IiIsIkZpcnLCJVaWQiOiIiLCJleHAiOjE2MzQzNzIwNTF9.ocpU8-0gCJsejmCeeEiL8DXhFcZsW7Z3OCN34HgIf2c",
  "created_at": "2021-10-09T08:14:11Z",
  "updtaed_at": "2021-10-09T08:14:11Z",
  "user_id": "61614f539f29be942bd9df8e",
  "usercart": [],
  "address": [],
  "orders": []
}

Login Function call create an outlayer for our collection

• Admin add Product Function POST REQUEST

  note this function is not seperated from normal user fixed soon for admin

  http://localhost:8000/admin/addproduct

{
  "product_name": "laptop",
  "price": 300,
  "rating": 10,
  "image": "1.jpg"
}

Response : "Successfully added our Product Admin!!"

• View all the Products in db GET REQUEST

  pagination added soon in next release

  http://localhost:8000/users/productview

Response

[
  {
    "Product_ID": "6153ff8edef2c3c0a02ae39a",
    "product_name": "notepad",
    "price": 50,
    "rating": 10,
    "image": "penc.jpg"
  },
  {
    "Product_ID": "616152679f29be942bd9df8f",
    "product_name": "laptop",
    "price": 300,
    "rating": 10,
    "image": "1.jpg"
  },
  {
    "Product_ID": "616152ee9f29be942bd9df90",
    "product_name": "top",
    "price": 300,
    "rating": 10,
    "image": "1.jpg"
  },
  {
    "Product_ID": "616152fa9f29be942bd9df91",
    "product_name": "table",
    "price": 300,
    "rating": 10,
    "image": "1.jpg"
  },
  {
    "Product_ID": "616153039f29be942bd9df92",
    "product_name": "apple",
    "price": 300,
    "rating": 10,
    "image": "1.jpg"
  }
]

• Search Product by regex function (GET REQUEST)

defines the word search sorting http://localhost:8000/users/search?name=le

response:

[
  {
    "Product_ID": "616152fa9f29be942bd9df91",
    "product_name": "table",
    "price": 300,
    "rating": 10,
    "image": "1.jpg"
  },
  {
    "Product_ID": "616153039f29be942bd9df92",
    "product_name": "apple",
    "price": 300,
    "rating": 10,
    "image": "1.jpg"
  }
]

The corresponding Query to mongodb is ProductCollection.Find(ctx, bson.M{"product_name": bson.M{"$regex": queryParam}})

• Adding the Products to the Cart (GET REQUEST)

  http://localhost:8000/addtocart?id=xxxproduct_idxxx&userID=xxxxxxuser_idxxxxxx

  Corresponding mongodb query

filter := bson.D{primitive.E{Key: "_id", Value: id}}
update := bson.D{{Key: "$push", Value: bson.D{primitive.E{Key: "usercart", Value: bson.D{{Key: "$each", Value: productcart}}}}}}
_, err = UserCollection.UpdateOne(ctx, filter, update)

• Removing Item From the Cart (GET REQUEST)

  http://localhost:8000/addtocart?id=xxxxxxx&userID=xxxxxxxxxxxx

  Corresponding mongodb query

filter := bson.D{primitive.E{Key: "_id", Value: usert_id}}

update := bson.M{"$pull": bson.M{"usercart": bson.M{"_id": removed_id}}}
_, err = UserCollection.UpdateMany(ctx, filter, update)

• Listing the item in the users cart (GET REQUEST) and total price

  http://localhost:8000/listcart?id=xxxxxxuser_idxxxxxxxxxx

  Corresponding Mongodb Query (WE are using the aggrgate operation to find sum)

   filter_match := bson.D{{Key: "$match", Value: bson.D{primitive.E{Key: "_id", Value: usert_id}}}}
  unwind := bson.D{{Key: "$unwind", Value: bson.D{primitive.E{Key: "path", Value: "$usercart"}}}}
  grouping := bson.D{{Key: "$group", Value: bson.D{primitive.E{Key: "_id", Value: "$_id"}, {Key: "total", Value: bson.D{primitive.E{Key: "$sum", Value: "$usercart.price"}}}}}}
  pointcursor, err := UserCollection.Aggregate(ctx, mongo.Pipeline{filter_match, unwind, grouping})
  

• Addding the Address (POST REQUEST)

  http://localhost:8000/addadress?id=user_id**\*\***\***\*\***

  The Address array is limited to two values home and work address more than two address is not acceptable

{
  "house_name": "jupyterlab",
  "street_name": "notebook",
  "city_name": "mars",
  "pin_code": "685607"
}

• Editing the Home Address(PUT REQUEST)

  http://localhost:8000/edithomeaddress?id=xxxxxxxxxxuser_idxxxxxxxxxxxxxxx

• Editing the Work Address(PUT REQUEST)

  http://localhost:8000/editworkaddress?id=xxxxxxxxxxuser_idxxxxxxxxxxxxxxx

• Delete Addresses(GET REQUEST)

  http://localhost:8000/deleteaddresses?id=xxxxxxxxxuser_idxxxxxxxxxxxxx

  delete both addresses

• Cart Checkout Function and placing the order(GET REQUEST)

  After placing the order the items have to be deleted from cart functonality added

  http://localhost:8000?id=xxuser_idxxx

• Instantly Buying the Products(GET REQUEST) http://localhost:8000?userid=xxuser_idxxx&pid=xxxxproduct_idxxxx

Code At Glance in main.go

All the routes defined here requires the api authentication key

Repo dedicting to my best friend mathappan 🐶 ,who left me without saying a goodbye and fill me with hopes even in my dark days RIP my friend

Here are some of the reference I gone through while working on this project

JWT Authentication using golang ¹

MongoDB Quick Introduction with Golang official blog ²

Package context instead of goroutine ³

Context use cases in real scenarios ⁴

Mongo GO Driver official Documentation ⁵

Mongo Go official go documentation ⁶

Is "logout" useless on a REST API? ⁷

JWT AUTHENTICATION OFFICIAL ⁸

Gin framework Documentation ⁹

Footnotes

1. https://dev.to/joojodontoh/build-user-authentication-in-golang-with-jwt-and-mongodb-2igd ↩

2. https://www.mongodb.com/blog/post/quick-start-golang-mongodb-starting-and-setup ↩

3. https://pkg.go.dev/context ↩

4. https://levelup.gitconnected.com/context-in-golang-98908f042a57 ↩

5. https://docs.mongodb.com/drivers/go/current/ ↩

6. https://pkg.go.dev/go.mongodb.org/mongo-driver/mongo ↩

7. https://stackoverflow.com/questions/36294359/is-logout-useless-on-a-rest-api ↩

8. github.com/golang-jwt/jwt ↩

9. https://github.com/gin-gonic/gin ↩