reading-notes

CRUD

Reading

• Status Codes Based on REST Methods
• VIDEO: Build A REST API With Node.js, Express, & MongoDB - Quick

Questions

Reading

• In your own words, describe what each group of status code represents:
  • 100’s = Informational codes that tell the client that the request has been received
  • 200’s = Successful request by the client
  • 300’s = Request redirected to current location
  • 400’s = Request not found
  • 500’s = Server is having an issue
• What is a status code 202?
  • All validation requirements were met for an asynchronous request
• What is a status code 308?
  • Permanent Redirect: the URL has moved and the client should stop using the current URL
• What code would you use if an update didn’t return data to a client?
  • 204 No Content
• What code would you use if a resource used to exist but no longer does?
  • 410 Gone
• What is the ‘Forbidden’ status code?
  • 403 Forbidden: client does not have permission to access the resource

Video

• Why do we need to pull our MongoDB database string out of our server and put it into our .env?
  • So that we can secure the location of our database from potential threats
• What is middleware?
  • Software that provides services to software applications beyond those available to the operating system
• What does app.use(express.json()) do?
  • Allows our server to accept JSON data
• What does the /:id mean in a route?
  • That it is a parameter and can be accessed with request.params.id
• What is the difference between PUT and PATCH?
  • PATCH updates only the information that is passed
  • PUT updates all the information at once
• How do you make a default value in a schema?
  • Add default: <defaultValue> to the schema
• What does a 500 error status code mean?
  • There was a server error
• What is the difference between a status 200 and a status 201?
  • 200 = “OK”, request was good
  • 200 = “OK”, request was successful and a resource was created as a result

Notes

Building an API Quick

• Steps
  1. npm i
  2. npm i express mongoose
     • Installs express
       • Makes interacting with Node.js easier
     • Installs mongoose
       • Allows us to interact with MongoDB
  3. npm i --save-dev dotenv nodemon
     • dotenv allows us to pull environmental variables from a .env file
     • nodemon allows us to update our server without needing to restart each time
  4. In package.json, change devStart to "devStart": "nodemon server.js"
  5. Create server.js file
  6. Create .env file
  7. Create .gitignore
     • Add .env
     • Add node_modules
  8. In server.js:
     • Import express
       • const express = require('express');
     • Declare app variable to configure the server
       • const app = express();
     • Add listen method to app to tell it what port to listen to
       • app.listen(3000, () => console.log('Server Started'))
     • Import mongoose
       • const mongoose = require('mongoose');
     • Connect mongoose to database
       • mongoose.connect('mongodb://<dbURL>, { useNewUrlParser: true })
     • Create db variable to handle events with the database
       • const db = mongoose.connection
     • Create error handler for database
       • db.on('error', (error) => console.error(error))
     • Create a proof of life that the database is connected
       • db.once('open', () => console.log('Connected to database'))
     • Set DATABASE_URL in .env file equal to your database URL in mongoose.connect
       • DATABASE_URL=://mongodb://<dbURL>
     • Inside server.js change dbURL to process.env.DATABASE_URL
     • Import .env variables
       • require('dotenv').config()
     • Setup server to accept JSON
       • app.use(express.json())
     • Setup routes
       • Create a routes folder
       • Define your routes: const <routeName> = require('./routes/<endpointName>')
     • You can now begin configuring routes in their own components

In Class Notes

Code Challenge: REGEX, Part 2

• Find actual ()
  • Need the \ before each ()
    • /\(206\)-123 selects (206) from a list of phone numbers
• Adding OR criteria with REGEX
  • | is the OR equivalent
    • Wrap OR criteria in () if there is an additional pattern to find after your conditional patterns
  • Type in as /<pattern1>|<pattern2>/gm

Lab 12: CRUD

• Will be adding in CRUD to the books database
  • Need to be able to:
    • Create new books
    • Read existing books’ data
    • Update existing books status
    • Delete existing books from DB
• Update
  • Will need to add a ROUTE that allows us to add books
    • app.post('/books', postBooks)

  • Create function to post the the books

    async function postBooks(req, res, next) {
      try{
        await Book.create(req.body);
      } catch(err) {
        next(err);
      }
    }
    

  • Add middleware

  • DELETE
    • Need to add a /:id parameter to the delete route so that it knows which book to delete
      • The id can be accessed with req.params.id
      • Use .findByIdAndRemove()

    async function deleteBooks(req, res, next) {
      try{
        away Book.findByIdAndDelete(req.params.id);
        res.send('Book deleted');
      } catch(err) {
        next(err);
      }
    }