Express & CRUD

Leon Noel

#100Devs

We come from poverty, man, we ain't have a thing
It's a lot of animosity, but they won't say my name

Agenda

• Questions? 
• Let's Talk -  #100Devs
• Review - CRUD 
• Review - Express
• Learn - Post & Delete
• Learn - Build your APP
• Homework - Build your own APP

Questions

About last class or life

Checking In

Submitting Work

Homework

(should be done)

Philip Roberts

Zell Liew

Thank You

Zell Liew

Summer Break

Break, Catch Up, Professional Stuff, 100Hours Project, and Hitlist

Backend!

NODE.js BABY

Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine.

Engine Vs. Compiler

And just like the browser's Web APIs Node come with a bunch of stuff

Built in Modules

(libraries or collections of functions)

HTTP (network access)

FS (file system access)

Access to millions of packages via NPM

(groupings of one or more custom modules)

Not Web APIs, but C/C++ APIs

sorry, don't remember the source

Let's Code

Simple Node Server

Just

HTTP & FS

const http = require('http')
const fs = require('fs')
http.createServer((req, res) => {
  fs.readFile('demofile.html', (err, data) => {
    res.writeHead(200, {'Content-Type': 'text/html'})
    res.write(data)
    res.end()
  })
}).listen(8000)

How could we clean this up?

Express

Express

Fast, unopinionated, minimalist web framework for Node.js

With a myriad of HTTP utility methods and middleware at your disposal, creating a robust API is quick and easy.

But First

Blast To The Past

How Does The Internet Work

"It is a set of rules that allow programs to talk to each other. The developer creates the API on the server and allows the client to talk to it."

CRUD

Create (post) - Make something

Read (get) - Get Something

Update (put) - Change something

Delete (delete) - Remove something

Mongo DB

Collection

document

document

document

document

EJS

(Embedded Javascript Templates)

    <h1>Current Rappers</h1>
    <ul class="rappers">
    <% for(let i=0; i < info.length; i++) {%>
        <li class="rapper">
            <span><%= info[i].stageName %></span>
            <span><%= info[i].birthName %></span>
            <span class='del'>delete</span>
        </li>
    <% } %>
    </ul>

    <h2>Add A Rapper:</h2>

Client (Laptop)

Browser

URL

Server

Disk

API Code

Files

Collection

Collection

document

document

document

document

app.get('/')

app.post('/form')

app.put('/info')

app.delete('/info')

/views

/public

index.ejs

main.js

style.css

Fonts

Images

Rap Names

What are some Read (get) requests?

Rap Names

What are some Create (post) requests?

Rap Names

What are some Delete (delete) requests?

Rap Names

What are some Update (put) requests?

Client (Laptop)

Browser

URL

Server

Disk

API Code

Files

Collection

Collection

document

document

document

document

app.get('/')

app.post('/form')

app.put('/info')

app.delete('/info')

/views

/public

index.ejs

main.js

style.css

Fonts

Images

Let's Build An App with Express

Key Steps

mkdir api-project
cd api-project
npm init 
npm install express --save
npm install mongodb --save
npm install ejs --save

Setting Up The Project

let db,
    dbConnectionStr = 'mongodb+srv://demo:demo@cluster0
    .2wapm.mongodb.net/rap?retryWrites=true&w=majority',
    dbName = 'rap'

MongoClient.connect(dbConnectionStr, { useUnifiedTopology: true })
    .then(client => {
        console.log(`Connected to ${dbName} Database`)
        db = client.db(dbName)
    })

Connect To DB

app.set('view engine', 'ejs')
app.use(express.static('public'))
app.use(express.urlencoded({ extended: true }))
app.use(express.json())



app.listen(process.env.PORT || PORT, ()=>{
    console.log(`Server running on port ${PORT}`)
})

Setup Server

app.get('/',(request, response)=>{
    db.collection('rappers').find().toArray()
    .then(data => {
        response.render('index.ejs', { info: data })
    })
    .catch(error => console.error(error))
})

API - GET

app.post('/addRapper', (request, response) => {
    db.collection('rappers').insertOne(request.body)
    .then(result => {
        console.log('Rapper Added')
        response.redirect('/')
    })
    .catch(error => console.error(error))
})

API - POST

Create EJS File

    <h1>Current Rappers</h1>
    <ul class="rappers">
    <% for(let i=0; i < info.length; i++) {%>
        <li class="rapper">
            <span><%= info[i].stageName %></span>
            <span><%= info[i].birthName %></span>
            <span class='del'>delete</span>
        </li>
    <% } %>
    </ul>

    <h2>Add A Rapper:</h2>

Create Public Folder/Files

app.delete('/deleteRapper', (request, response) => {
    db.collection('rappers').deleteOne({stageName: request.body.stageNameS})
    .then(result => {
        console.log('Rapper Deleted')
        response.json('Rapper Deleted')
    })
    .catch(error => console.error(error))

})

API - DELETE

heroku login -i
heroku create simple-rap-api
echo "web: node server.js" > Procfile
git add . 
git commit -m "changes"
git push heroku main

Push To Heroku

Let's Code

Rap Names App

Homework