RESTful API

Understanding HTTP status codes

Creating a API connected MongoDB using Express

Importing modules, like express, mongoose, body-parser

const express = require("express");
const mongoose = require("mongoose");
const bodyParser = require("body-parser");

Establishing Connection with MongoDB using mongoose

mongoose
  .connect("mongodb://127.0.0.1:27017/productStore", {
    useNewUrlParser: true,
    useUnifiedTopology: true,
  })
  .then(() => {
    console.log("Connected to MongoDB successfully");
  })
  .catch((error) => {
    console.log(error);
  });

Creating App reference using Express

const app = expresss();

Using bodyParser in app to avoid this bug,

app.use(bodyParser.urlencoded({ extended: false }));

Using express.json() in app to avoid this bug, where only "success" shows up, and it misses "name", "email", " password" from response.json().

app.use(express.json());

Defining port and host,

const PORT = 4000;
const HOST = "localhost";

Defining a schema of object and creating a new model

const productSchema = new mongoose.Schema({
  name: String,
  description: String,
  price: Number,
});
 
const Product = new mongoose.model("Product", productSchema);

Reading the path to receive data, from POST() to create new product

app.post("/api/v1/product/new", async (request, response) => {
  const product = await Product.create(request.body);
 
  response.status(201).json({
    success: true,
    product,
  });
});

Setting up the web server, to listen to host:port

app.listen(PORT, HOST, () => {
  console.log(`Server is working: http://${HOST}:${PORT}`);
});

Get all products, from /api/v1/products ,

app.get("/api/v1/products", async (request, response) => {
  const products = await Product.find();
 
  response.status(200).json({ success: true, products });
});

Modify product detail usiing product id from /api/v1/product/:id

app.put("/api/v1/product/:id", async (request, response) => {
  let product = await Product.findById(request.params.id);
 
  product = await Product.findByIdAndUpdate(request.params.id, request.body, {
    new: true,
    useFindAndModify: true,
    runValidators: true,
  });
 
  response.status(200).json({
    success: true,
    product,
  });
});

Delete product detail usiing product id from /api/v1/product/:id

app.delete("/api/v1/product/:id", async (request, response) => {
  const product = await Product.findById(request.params.id);
 
  if (!product) {
    return response.status(500).json({
      success: false,
      message: "Product not found",
    });
  }
  await product.deleteOne();
 
  response.status(200).json({
    success: true,
    product,
  });
});

Adding Backend Validation using YUP

Installing yup package for validation using npm install yup.
Defining the schema to product, /validation/validateProduct.js,

const yup = require("yup");
 
const productSchema = yup.object({
  name: yup.string().required().min(5).max(30),
  description: yup.string().min(10).max(100).required(),
  price: yup.number().required().max(10),
});
 
module.exports = productSchema;

Creating a middleware that takes schema as parameter, to validate the request with the schema, /middleware/validateMiddleWare.js

const validation = (schema) => async (request, response, next) => {
  const body = request.body;
  try {
    await schema.validate(body);
    next(); // next() is used to keep moving forward
  } catch (error) {
    return response.status(422).json({ error: error });
  }
};
 
module.exports = validation;

Importing validation() and schema in app.js, and in Rest API functions call, add validation(schema) as parameter.

const validation = require("./middleware/validateMiddleware");
const validateSchema = require("./validation/validateProduct");
 
app.post(
  "/api/v1/product/new",
  validation(validateSchema),
  async (request, response) => {
    const product = await Product.create(request.body);
    response.status(201).json({
      success: true,
      product,
    });
  }
);

3. Mongodb Terminal Basics