GettingStartedWithNode.md

1. Create a directory and an npm module for you service using npm init from the command line in the directory. This creates a package.json file that will configure how that service runs. Use server.js instead of index.js
2. Add express dependancy to your project. From the comman line type:

npm i -s express

This means "node package manager, install (i) and save it to the package.json file (-s) the express package".

3. Create a server.js file like:

const express = require('express')
const app = express()
const port = 3000

app.get('/', (req, res) => res.send('Hello World!'))

app.listen(port, () => console.log(`Example app listening at http://localhost:${port}`))

4. An end point that does something useful...

app.get('/users/:userId/books/:bookId', function (req, res) {
  res.send(req.params)
})

Side stuff:

linux commands cd - change directory ls - list files cd .. go to the parent directory pwd - show the current directory mkdir - make dir

server.js

const express = require('express')

const fs = require('fs')

const app = express()
const port = 3003

// load the data from a file

// when we add new records, rewrite the file as well as
// keeping it updated in memory

// https://nodejs.org/api/fs.html

// this can be async, as we want to give the user the results, then
// worry about saving it later - we can carry on after a vote has been
// cast.
// You will need to load JSON.stringify(object) and JSON.decode(string)

const saveData = () => {

};

// only used for the initial load, and we can't do anything until we
// have it -> so it needs to load synchronously.
const loadData = () => {

    // loads the data file

    // 
};

// this is where you do the load
const votes = {

};

/*
votes will be like:

{
    'roy': 10,
    'mansun': 15,
    'dobby': 19
}
*/

app.get('/', (req, res) => res.send('Hello World!'))

// list all the dogs in our data
app.get('/dogs', function (req, res) {
    return res.send(Object.keys(votes))
});

app.get('/dog/:dogId/votes', function (req, res) {

    // get the dogId
    const { dogId } = req.params;

    // is the dog in our data?
    if (votes[dogId]) {
        return res.send({ votes: votes[dogId] })
    }
    res.send({ votes: 0 });
})

// this really should be app.post - when connected to a front end
app.get('/dog/:dogId/vote', function (req, res) {

    // log to the server console (not the browser!)
    console.log('someone is voting...')
    // work out what the dog Id is:
    const { dogId } = req.params;

    // initialise the votes for dogId if there aren't any
    if (!votes[dogId]) {
        votes[dogId] = 0
    }
    // record the vote
    votes[dogId]++

    // tell us how many votes a particular dog has
    res.send({ votes: votes[dogId] })

    // @TODOS: async save goes here...


})


  app.listen(port, () => console.log(`Example app listening at http://localhost:${port}`))