server.js

/*
    Code    : Sensor data visualization (Backend)
    Author  : Atick Faisal
    License : MIT
    Date    : 19.07.2019
*/

const express = require('express');
const bodyParser = require('body-parser');
const mongoose = require('mongoose');
const Item = require('./models/item');
const path = require('path');
const mongoURI = require('./config/key').admin;

// connect to the database
mongoose
    .connect(mongoURI, {
        useNewUrlParser: true
    })
    .then(() => console.log('MongoDB connected...'))
    .catch(err => console.log(err));

const app = express();

// use body-parser middleware
app.use(bodyParser.json());

// ------------------- react app  static server -------------------//
app.use(express.static(path.join(__dirname, 'client/build')));
app.get('/', function(req, res) {
    res.sendFile(path.join(__dirname, 'client', 'build', 'index.html'));
});
//-----------------------------------------------------------------//

// handle get reuests
// sends the last 7 values
// react app sensds this get request
app.get('/api/sensors', function(req, res) {
    Item.find()
        .then(items => res.json(items.slice(items.length - 6, items.length)))
        .catch(err => console.log(err));
});

// handle post requests
app.post('/api/sensors', function(req, res) {
    // create new item using the schema
    const newItem = new Item({
        temp: req.body.temp,
        hum: req.body.hum,
        light: req.body.light
    });
    // save value to database
    newItem.save()
        .then(item => res.json(item));
    console.log(req.body);
});

// start the server @localhost:5000
const port = process.env.PORT || 5000;
app.listen(port, function() {
    console.log(`Server started on port ${port}`);
});