yagosansz / rocketseat-bootcamp2020-module01

rocketseat-bootcamp2020-module01

Understanding Node.JS - Basic Concepts

What is this project about?

This is project is about practicing the basic concepts behind Node.JS that were learned during the first module of GoStack 10 - Bootcamp.

How to run this project?

• Install dependencies:

  • yarn

• Start the back-end:

  • yarn dev

• It's possible to test the GET methods through the browser, but for the other methods I recommend using applications such as Insomnia or Postman.

Logbook

Day 01 - 2020/01/27

• Basic Concepts of a REST API

  • How does it work?
    • Resquest & Response flow:
      1. Request is made by the client (e.g.: browser)
      2. Response is returned - by the server - through a data structure (e.g.: JSON)
      3. Client gets the response and processes the result

• Routes use HTTP methods

  1. GET: http://myapi.com/users
     • Looks for data
  2. POST: http://myapi.com/users
     • Creates data
  3. PUT: http://myapi.com/users/1
     • Updates a piece data
  4. DELETE: http://myapi.com/users/3
     • Deletes a piece of data

• Benefits

  • Multiple clients (front-end) using the same back-end
  • Standard communication protocol
    • Same structure for web/mobile/public API
    • Communication with external services

• Request Content

  • GET: http://myapi.com/company/1/users?page=2

    • routes: /company & /users
    • route params: /1/
    • query params: ?page=2

  • POST: http://myapi.com/company/1/users?page=2

    • User data to be created is sent through the body/request body (PUT/POST only)
      • More detailed/sensitive data

  • Headers: Additional information that is not related to the request's content (e.g.: { "locale": "pt_BR })

Day 02 - 2020/01/28

• HTTP Codes: Every response (back-end -> front-end) takes with it a HTTP code, that represents the response's status.
  1. 1xx: INFORMATIONAL
  2. 2xx: SUCCESS
     • 200: success
     • 201: created
  3. 3xx: REDIRECTION
     • 301: moved permanently
     • 302: moved
  4. 4xx: CLIENT ERROR (there is something wrong with the request)
     • 400: bad request
     • 401: unauthorized
     • 404: not found
  5. 5xx: SERVER ERROR
     • 500: internal server error

Day 03 - 2020/01/29

• Creating the application

  • yarn init -y

• package.json

  • It has the important functionality, among many others, of saving the references to the project dependencies that were installed.

• index.js

  const express = require('express'); // exports a function
  
  // Notice that express is a function that
  // returns an object with many functionalities
  console.log(express);

• There are three types of parameters that can be part of a request:

  1. Query params -> ?name=John

    const { name } = request.query

  2. Route params -> /users/1 -> /users/:id

    const { id } = request.params

  3. Body/Request body -> { "name": "John", "age": 27 }

    const { name, age } = request.body

• Middlewares (Global and Local)

  • They are a fundamental part of every Express application!
  • It's a function that gets request and response as parameters (among others, e.g.: next) and transforms/check data.
  1. Global
  • It's always invoked, no matter what route is being triggered.

  server.use((req, res) => {
    console.time('Request');
    console.log(`Method: ${req.method}; URL: ${req.url}`);
    next();
    console.timeEnd('Request');
  });

  2. Local

  • It's applied directly to routes

  • You can add as many middlewares as you feel necessary.

  • Middlewares can change the request and response parameters.

• Debugging the application

  • Learned how to use breakpoints in VSCode.
  • Understand variables' values and what is happening behind the scenes in the application.

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Made with ♥ by Yago!