12

NodeJS + Express part 4: CRUD API

 2 years ago
source link: https://dev.to/ericchapman/nodejs-express-part-4-crud-api-37ef
Go to the source link to view the article. You can view the picture content, updated content and better typesetting reading experience. If the link is broken, please click the button below to view the snapshot at that time.
neoserver,ios ssh client

expressJS (4 Part Series)

Here is a series of articles that will allow you to create backend applications with NodeJS + Express.

This series is the continuation of my series on the basics of NodeJS. If you don't have basic knowledge of NodeJS read this series first: Introduction to NodeJS

Node.js is today a must, so it is essential for a developer to master it.

So I will publish a new article about every two days and little by little you will learn everything there is to know about Node.js + Espress

To not miss anything follow me on twitter: https://twitter.com/EricTheCoder_

CRUD API

Now that we know the basics concept, it's time to build real CRUD API (create, read, update, delete)

We will build all those CRUD routes:

Create: POST /api/products

Read all: GET /api/products

Read: GET /api/product/1

Update: PUT /api/products/1

Delete: DELETE /api/products/1

Return status

With a CRUD API you can return data but also status code.

Here is a list of some status code and there meaning

res.status(200) // Ok
res.status(201) // Created
res.status(204) // No content
res.status(400) // Bad request
res.status(401) // Unauthorized
res.status(403) // Forbidden
res.status(404) // Not found
res.status(500) // Server error
Enter fullscreen modeExit fullscreen mode

Create a file name data.js and copy/paste this code 

const products = [
    { id: 1, name: 'iPhone', price: 800 },
    { id: 2, name: 'iPad', price: 650 },
    { id: 3, name: 'iWatch', price: 750 }
]

module.exports = products
Enter fullscreen modeExit fullscreen mode

Load data and start the server 

const express = require('express')
const app = express()
const products = require('./data.js')

app.listen(5000, () => {
    console.log('server is listening on port 5000')
})
Enter fullscreen modeExit fullscreen mode

Create: POST /api/products 

app.use(express.json()) // parse json body content

app.post('/api/products', (req, res) => {
    const newProduct = {
        id: products.length + 1,
        name: req.body.name,
        price: req.body.price
    }
    products.push(newProduct)
    res.status(201).json(newProduct)
})
Enter fullscreen modeExit fullscreen mode

The app.use(express.json) is a middleware that take JSON content and create related req.body properties. (ex. req.body.name and req.body.price)

The res.status(201).json(newProduct) set the return response status to 201 (created) and also return the newProduct data in JSON format.

Read all: GET /api/products 

app.get('/api/products', (req, res) => {
    res.json(products)
})
Enter fullscreen modeExit fullscreen mode

Read: GET /api/product/1 

app.get('/api/products/:productID', (req, res) => {
    const id = Number(req.params.productID)
    const product = products.find(product => product.id === id)

    if (!product) {
        return res.status(404).send('Product not found')
    }
    res.json(product)
})
Enter fullscreen modeExit fullscreen mode

As seen in part 2, first we retrieved the productID from the route parameter.

Then we check if this product exist and send a response accordingly.

res.json(product) send the product in JSON format with a 200 ok status code.

Update: PUT /api/products/1 

app.use(express.json()) // parse json body content

app.put('/api/products/:productID', (req, res) => {
    const id = Number(req.params.productID)
    const index = products.findIndex(product => product.id === id)
    if (index === -1) {
        return res.status(404).send('Product not found')
    }
    const updatedProduct = {
        id: products[index].id,
        name: req.body.name,
        price: req.body.price
    }
    products[index] = updatedProduct
    res.status(200).json('Product updated')
})
Enter fullscreen modeExit fullscreen mode

Delete: DELETE /api/products/1 

app.use(express.json()) // parse json body content

app.delete('/api/products/:productID', (req, res) => {
    const id = Number(req.params.productID)
    const index = products.findIndex(product => product.id === id)
        if (index === -1) {
        return res.status(404).send('Product not found')
    }
    products.splice(index,1)
    res.status(200).json('Product deleted')
})
Enter fullscreen modeExit fullscreen mode

Conclusion

That's all for today, follow me on twitter: https://twitter.com/EricTheCoder_ to be notified of the publication of the next article (within two days).


report

Recommend

About Joyk


Aggregate valuable and interesting links.
Joyk means Joy of geeK