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Backend

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Wellington Silva edited this page Mar 30, 2020 · 1 revision

Node.js

 mkdir backend
 cd backend
 npm init -y # incializando node.js
 npm install express # instalando micro-framework 'express' (configura rota e interpreta parâmetros)
 touch index.js
  • request: guarda todos os dados que são fornecidos da requisição do usuário
  • response: responder todos os dados que são requisitados pelo usuário
const express = require('express'); 

const app = express();

app.get('/',(request, response) => {
	return response.send('Hello World');
});

app.listen(3333);
 node index.js # ativa o localhost:3333

Rota e Recursos

Métodos HTTP

  • GET: Buscar/Listar uma informação do back-end
  • POST: Cria uma informação do back-end
  • PUT: Altera uma informação do back-end
  • DELETE: Delete uma informação do back-end

Insomnia.rest : (Ferramenta para manipular os Métodos HTTP)

$ sudo snap install insomnia
Login

Client Code

var data = JSON.stringify({
  "id": "aa1e8513"
});

var xhr = new XMLHttpRequest();
xhr.withCredentials = true;

xhr.addEventListener("readystatechange", function () {
  if (this.readyState === this.DONE) {
    console.log(this.responseText);
  }
});

xhr.open("POST", "http://localhost:3333/sessions");
xhr.setRequestHeader("authorization", "aa1e8513");
xhr.setRequestHeader("content-type", "application/json");

xhr.send(data);
POST /sessions HTTP/1.1
Authorization: aa1e8513
Content-Type: application/json
Host: localhost:3333
Content-Length: 22

{
	"id" : "aa1e8513"
}

Curl

curl --request POST \
  --url http://localhost:3333/sessions \
  --header 'authorization: aa1e8513' \
  --header 'content-type: application/json' \
  --data '{
	"id" : "aa1e8513"
}'
Profile

Client Code

var data = null;

var xhr = new XMLHttpRequest();
xhr.withCredentials = true;

xhr.addEventListener("readystatechange", function () {
  if (this.readyState === this.DONE) {
    console.log(this.responseText);
  }
});

xhr.open("GET", "http://localhost:3333/profile");
xhr.setRequestHeader("authorization", "aa1e8513");

xhr.send(data);
GET /profile HTTP/1.1
Authorization: aa1e8513
Host: localhost:3333

Curl

curl --request GET \
  --url http://localhost:3333/profile \
  --header 'authorization: aa1e8513'
Casos
  • List

Client Code

var data = null;

var xhr = new XMLHttpRequest();
xhr.withCredentials = true;

xhr.addEventListener("readystatechange", function () {
  if (this.readyState === this.DONE) {
    console.log(this.responseText);
  }
});

xhr.open("GET", "http://localhost:3333/incidents?page=1");
xhr.setRequestHeader("authorization", "aa1e8513");

xhr.send(data);
GET /incidents?page=1 HTTP/1.1
Authorization: aa1e8513
Host: localhost:3333

Curl

curl --request GET \
  --url 'http://localhost:3333/incidents?page=1' \
  --header 'authorization: aa1e8513'
  • Create

Client Code

var data = JSON.stringify({
  "title": "Casos 1",
  "description": "Detalhes dos casos",
  "value": 120
});

var xhr = new XMLHttpRequest();
xhr.withCredentials = true;

xhr.addEventListener("readystatechange", function () {
  if (this.readyState === this.DONE) {
    console.log(this.responseText);
  }
});

xhr.open("POST", "http://localhost:3333/incidents");
xhr.setRequestHeader("content-type", "application/json");
xhr.setRequestHeader("authorization", "aa1e8513");

xhr.send(data);
POST /incidents HTTP/1.1
Content-Type: application/json
Authorization: aa1e8513
Host: localhost:3333
Content-Length: 89

{ 
	"title" 			: "Casos 1",  
	"description" : "Detalhes dos casos", 
	"value" 			: 120
}

Curl

curl --request POST \
  --url http://localhost:3333/incidents \
  --header 'authorization: aa1e8513' \
  --header 'content-type: application/json' \
  --data '{ 
	"title" 			: "Casos 1",  
	"description" : "Detalhes dos casos", 
	"value" 			: 120
}'
  • Delete

Client Code

var data = null;

var xhr = new XMLHttpRequest();
xhr.withCredentials = true;

xhr.addEventListener("readystatechange", function () {
  if (this.readyState === this.DONE) {
    console.log(this.responseText);
  }
});

xhr.open("DELETE", "http://localhost:3333/incidents/3");
xhr.setRequestHeader("authorization", "aa1e8513");

xhr.send(data);
DELETE /incidents/3 HTTP/1.1
Authorization: aa1e8513
Host: localhost:3333

Curl

curl --request DELETE \
  --url http://localhost:3333/incidents/3 \
  --header 'authorization: aa1e8513'
Ongs
  • List

Client Code

var data = null;

var xhr = new XMLHttpRequest();
xhr.withCredentials = true;

xhr.addEventListener("readystatechange", function () {
  if (this.readyState === this.DONE) {
    console.log(this.responseText);
  }
});

xhr.open("GET", "http://localhost:3333/ongs");

xhr.send(data);
GET /ongs HTTP/1.1
Host: localhost:3333

Curl

curl --request GET \
  --url http://localhost:3333/ongs
  • Create

Client Code

var data = JSON.stringify({
  "name": "APAD2",
  "email": "contato@apad.com.br",
  "whatsapp": "470000000",
  "city": "Rio do Sul",
  "uf": "SC"
});

var xhr = new XMLHttpRequest();
xhr.withCredentials = true;

xhr.addEventListener("readystatechange", function () {
  if (this.readyState === this.DONE) {
    console.log(this.responseText);
  }
});

xhr.open("POST", "http://localhost:3333/ongs");
xhr.setRequestHeader("content-type", "application/json");

xhr.send(data);
POST /ongs HTTP/1.1
Content-Type: application/json
Host: localhost:3333
Content-Length: 131

{
	"name" 		 : "APAD2",
	"email" 	 : "contato@apad.com.br",
	"whatsapp" : "470000000",
	"city" 		 : "Rio do Sul",
	"uf"			 : "SC"
}

Curl

curl --request POST \
  --url http://localhost:3333/ongs \
  --header 'content-type: application/json' \
  --data '{
	"name" 		 : "APAD2",
	"email" 	 : "contato@apad.com.br",
	"whatsapp" : "470000000",
	"city" 		 : "Rio do Sul",
	"uf"			 : "SC"
}'

Tipos de parâmetros

  • Query Params: parâmetros nomeados enviados na rota após "?". Exemplo: filtro, páginação;
  • Route Params: parâmetros utilizados para identificar recursos ;
  • Request Body: Corpo da requisição, utilizado para criar ou alterar recursos.
    • Converter json para javascript: app.use(express.json());.

Banco de dados

Modelo Conceitual: Entidades e Funcionalidades

  • ONG
    • Cadastrar
    • Login
    • Logout
    • Contato
  • CASOS (incident)
    • Cadastrar
    • Deletar
    • Listar
      • Especificos
      • Todos

SQLite

  • Driver: SELECT * FROM users
  • Query Builder: table('users').select( * ).where()

Knex.js

  • Install
npm install knex 
npm install sqlite3
npx knex init # configura o acesso ao banco de dados para cada aplicação

Migrations

  • Configuração do database pelo knex 
// knexfile.js
development: {
    client: 'sqlite3',
    connection: {
        filename: './src/database/db.sqlite'
    },
    migrations: {
        directory: './src/database/migrations'
    },
    useNullAsDefault: true
},
  • gera uma tabela apenas no knexfile create schema 
npx knex migrate:make create_ongs
  • configura a estrutura da tabela para o comando create table 
// 20200325083011_create_ongs.js
exports.up = function(knex) {
  return knex.schema.createTable('ong', function (table) {
    table.string('id').primary();
    table.string('name').notNullable();
    table.string('email').notNullable();
    table.string('whatsapp').notNullable();
    table.string('city').notNullable();
    table.string('uf',2).notNullable();
  })
};

exports.down = function(knex) { return knex.schema.dropTable('ongs'); };
  • executa o comando create table e cria tabela no banco de dados
npx knex migrate:latest
  • Desfaz o último comando do npx knex migrate:latest 
npx knex migrate:rollback

Módulo de Segurança

Cross-Origin Resource Sharing (CORS)

Define quem possui autoridade de acessar a aplicação

npm install cors

Exemplo de uso:

app.use(cors({
    origin: 'domínio_da_app.com'
}));
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