JasonMarkWomack/node-day-2

Notes and code from Day 2 lecture - DM16

node-day-2

Notes and code from Day 2 lecture - DM16

common data structures

• array of objects

var books = [{
  name: ‘Harry Potter’,
  author: ‘JK Rowling’
}, {
  name: ‘LOTR’,
  author: ‘JRR Tolkein’
}, {
  name: ‘GOT’,
  author: ‘George RR Martin’
}];

• other examples: movies, schools, users

CRUD (create, read, update, delete) / module.exports

module.exports (remember the ’s’)

// 1. module.exports at the top and have function declarations
module.exports = {
  getBooks: getBooks,
  updateBooks: updateBooks,
  deleteBook: deleteBook
}

// 2. module.exports and write in the object itself
module.exports = {
  create: function (req, res, next) {
  
  },
  read: function (req, res, next) {
  
  },
  update: function (req, res, next) {
  
  },
  destroy: function (req, res, next) {
  
  },
  index: function (req, res, next) {
  
  }
}

// 3. module.exports at the bottom and use function declarations OR expressions

// 4. module.exports.functionName after every function

req.params (path params)

• just like Angular
• ‘/books/:id’ where :id is your req.params.id

req.query (URL query)

• anything after the ‘?’ in the url
• key=value format. spaces get a ‘+’
• different queries are separated with ‘&’
• ‘/books?id=0&name=harry+potter’

req.query = { id: 0, name: ‘harry potter’ }

tip: if you’re not sure, console.log()

Multiple files

• similar to Angular where you divide up code by functionality
• use module.exports to export out code from a file
• use var whateverName = require(‘/path/to/file/with/code/we/want’)

Naming Conventions

• just be consistent and descriptive

Chaining Functions and next()

• express does things in order
• you need to call next() to get to the next function in the chain

Middleware

• if you use app.use then this will run for every single request
• if you want to only use it for some some requests, then make a function, and then add it to specific endpoints

app.use(iAmUsedForEveryRequest());

function onlyUsedWhenIWantMiddleware (req, res, next) {
  // do stuff
  next()
  // if you don’t call next it won’t continue
}

app.get(‘/books’, onlyUsedWhenIWantMiddleware, function(req, res, next) {
  // stuff
});