app.js

const express = require("express");
const bodyParser = require("body-parser");
const ejs = require ("ejs");
const mongoose = require ("mongoose");
const app = express();

app.set('view engine', 'ejs');
app.use(bodyParser.urlencoded({extended: true}));
app.use(express.static("public"));

mongoose.connect("mongodb://localhost:27017/wikiDB", {useNewUrlParser: true, useUnifiedTopology: true});

const articleSchema = {
  title: String,
  content: String
};

const Article = mongoose.model("Article", articleSchema);

///////////////request targeting all articles//////////////////

app.route("/articles")
  .get(function(req, res){
    Article.find({}, function(err, foundArticles){
      if (!err) {
        res.send(foundArticles);
      } else {
        res.send(err);
      }    
    });
  })
  .post(function(req, res){
    const newArticle = new Article ({
      title: req.body.title,
      content: req.body.content
    });
    newArticle.save(function(err){
      if (!err) {
        res.send("New article added.");
      } else {
        res.send(err);
      }
    });
  })
  .delete(function(req, res){
    Article.deleteMany({}, function(err){
      if (!err) {
        res.send("All articles deleted."); 
      } else {
        res.send(err);
      }
    });
  });

///////////////request targeting a specific article//////////////////

app.route("/articles/:articleTitle")
  .get(function(req, res){
    Article.findOne({title: req.params.articleTitle}, function(err, foundArticle){
      if (!err) {
        res.send(foundArticle);
      } else {
        res.send("No matching articles found.");
      }
    });
  })
  .put(function(req, res){
    Article.updateOne(
      {title: req.params.articleTitle},
      {title: req.body.title, content: req.body.content},
      function(err, results){
        if (!err) {
          res.send("Succesfully update the article.");
        } else {
          res.send(err);
        }
      }
    )
  })
  .patch(function(req, res){
    Article.updateOne(
      {title: req.params.articleTitle},
      {$set: req.body},
      function(err){
        if (!err){
          res.send("articl updated succesfully");
        } else {
          res.send(err);
        }
      }
    )
  })
   .delete(function(req, res){
    Article.deleteOne({title: req.params.articleTitle}, function(err){
      if (!err) {
        console.log(req.params.articleTitle);
        res.send("Article deleted");
      } else {
        res.send(err);
      }
    })
  });



app.listen(3000, function(){
  console.log("Server started on port 3000");
});