server.js

var express = require("express");
var logger = require("morgan");
var mongoose = require("mongoose");
var mongojs = require("mongojs");
var exphbs = require("express-handlebars");

// Our scraping tools
// Axios is a promised-based http library, similar to jQuery's Ajax method
// It works on the client and on the server
var axios = require("axios");
var cheerio = require("cheerio");

// Require all models
var db = require("./models");

var PORT = process.env.PORT || 3000;

// Initialize Express
var app = express();

// Configure middleware

// Use morgan logger for logging requests
app.use(logger("dev"));
// Parse request body as JSON
app.use(express.urlencoded({ extended: true }));
app.use(express.json());
// Make public a static folder
app.use(express.static("public"));

// Handlebars
app.engine(
  "handlebars",
  exphbs({
    defaultLayout: "main"
  })
);
app.set("view engine", "handlebars");


var databaseURI = "mongodb://localhost/scrapinghw";

if (process.env.MONGODB_URI) {
  mongoose.connect(process.env.MONGODB_URI/*, { useNewUrlParser: true }*/);
} else {
  mongoose.connect(databaseURI, { useNewUrlParser: true });
}


// Routes

app.get("/", function(req, res) {
    res.render("index");
});


// A GET route for scraping the echoJS website
app.get("/scrape", function(req, res) {
  // First, we grab the body of the html with axios
  axios.get("https://www.sitepoint.com/community/c/javascript").then(function(response) {

  // Then, we load that into cheerio and save it to $ for a shorthand selector
    
    console.log(response.data);
    
    var $ = cheerio.load(response.data);

    // Now, we grab every h2 within an article tag, and do the following:
    $("div").each(function(i, element) {
      // Save an empty result object
      var result = {};

      // Add the text and href of every link, and save them as properties of the result object
      result.title = $(this)
        .children("a")
        .children("span")
        .text();
      result.link = $(this)
        .children("a")
        .attr("href");

      // Create a new Article using the `result` object built from scraping
      db.Article.create(result)
        .then(function(dbArticle) {
          // View the added result in the console
          console.log(dbArticle);
        })
        .catch(function(err) {
          // If an error occurred, log it
          //console.log(err);
        });
      });
    });

    res.json("dummy");

  });


// Route for getting all Articles from the db
app.get("/articles", function(req, res) {
  // Grab every document in the Articles collection
  db.Article.find({})
    .then(function(dbArticle) {
      // If we were able to successfully find Articles, send them back to the client
      res.json(dbArticle);
    })
    .catch(function(err) {
      // If an error occurred, send it to the client
      res.json(err);
    });
});

// Route for grabbing a specific Article by id, populate it with it's note
app.get("/articles/:id", function(req, res) {
  // Using the id passed in the id parameter, prepare a query that finds the matching one in our db...
  db.Article.findOne({ _id: req.params.id })
    // ..and populate all of the notes associated with it
    .populate("note")
    .then(function(dbArticle) {
      // If we were able to successfully find an Article with the given id, send it back to the client
      res.json(dbArticle);
    })
    .catch(function(err) {
      // If an error occurred, send it to the client
      res.json(err);
    });
});

// Route for saving/updating an Article's associated Note
app.post("/articles/:id", function(req, res) {
  // Create a new note and pass the req.body to the entry
  db.Note.create(req.body)
    .then(function(dbNote) {
      // If a Note was created successfully, find one Article with an `_id` equal to `req.params.id`. Update the Article to be associated with the new Note
      // { new: true } tells the query that we want it to return the updated User -- it returns the original by default
      // Since our mongoose query returns a promise, we can chain another `.then` which receives the result of the query
      return db.Article.findOneAndUpdate({ _id: req.params.id }, { note: dbNote._id }, { new: true });
    })
    .then(function(dbArticle) {
      // If we were able to successfully update an Article, send it back to the client
      res.json(dbArticle);
    })
    .catch(function(err) {
      // If an error occurred, send it to the client
      res.json(err);
    });
});

// Route for deleting an Article's associated Note
app.put("/articles/:id", function(req, res) {
  // Create a new note and pass the req.body to the entry

  console.log(req.body);

  db.Note.findOne({title : req.body.title/*, body : req.body.body*/})
    .then(function(dbNote) {
      console.log("dbNote._id: " + dbNote._id);
      db.Note.deleteOne({_id: mongojs.ObjectId(dbNote._id)})
      .then(function(result) {
        if (result.deletedCount === 0) {
            throw new Error('No document to delete with ID: ' + _id);
        }
        console.log(req.params.id);
        db.Article.updateOne(
            { _id: mongojs.ObjectId(req.params.id) },
            { $unset: { note: "" } }
        )
        .then(function(error, edited) {
          if (error) throw error;
          else
          console.log(edited);
          res.send(edited)
          });
      })

    .then(function(dbArticle) {
      // If we were able to successfully update an Article, send it back to the client
      res.json(dbArticle);
    })
    .catch(function(err) {
      // If an error occurred, send it to the client
      res.json(err);
    });

  });
});

// Route for grabbing a specific Note by id, populate it with it's note
app.get("/notes/:id", function(req, res) {
  // Using the id passed in the id parameter, prepare a query that finds the matching one in our db...
  db.Note.findOne({ _id: req.params.id })
    // ..and populate all of the notes associated with it
    .then(function(dbNote) {
      // If we were able to successfully find an Article with the given id, send it back to the client
      res.json(dbNote);
    })
    .catch(function(err) {
      // If an error occurred, send it to the client
      res.json(err);
    });
});

// Route for deleting all articles from db
app.put("/clear", function(req, res) {
  // Create a new note and pass the req.body to the entry
  console.log(req.body);

  db.Article.deleteMany({})
  .then(function(result) {
    console.log("Deleted "+result.deletedCount+" articles");
  })
  .catch(function(err) {
    // If an error occurred, send it to the client
    res.json(err);
  });

});


const host = '0.0.0.0';

// Start our server so that it can begin listening to client requests.
app.listen(PORT, host, function() {
  // Log (server-side) when our server has started
  console.log("Server listening on: http://localhost:" + PORT);
});