02_setup_app_js.md

Setup app.js

• Create /helpers/utils.helper.js:

  "use strict";
  utilsHelper = {};
  utilsHelper.sendResponse = (res, status, success, data, errors, message) => {
    const response = {};
    if (success) response.success = success;
    if (data) response.data = data;
    if (errors) response.errors = errors;
    if (message) response.message = message;
    res.status(status).json(response);
  };
  module.exports = utilsHelper;

• In app.js, add:

  +const utilsHelper = require("./helpers/utils.helper");
  
  const app = express();

• In routes/, delete users.js. In app.js,remove

  -const usersRouter = require("./routes/users");
  ...
  -app.use("/users", usersRouter);

• Create routes/message.api.js:

  const express = require("express");
  const router = express.Router();
  
  /**
   * @route GET api/messages?page=1&limit=10
   * @description Get messages with pagination
   * @access Public
   */
  router.get("/", function (req, res, next) {
    res.send({ status: "ok", data: "Cs Mail" });
  });
  
  module.exports = router;

• In routes/index.js, replace everything with:

  const express = require("express");
  const router = express.Router();
  
  // messageAPI
  const messageAPI = require("./message.api");
  router.use("/messages", messageAPI);
  
  module.exports = router;

  In app.js, change:

  -app.use("/", indexRouter);
  +app.use("/api", indexRouter);

• Import cors:

  const logger = require("morgan");
  +const cors = require("cors")
  ...
  app.use(cookieParser());
  +app.use(cors());

• Connect to DB

  • In .env, add

  MONGODB_URI='mongodb://localhost:27017/social_message'
  

  • In app.js:

  const mongoose = require('mongoose')
  const mongoURI = process.env.MONGODB_URI
  ...
  app.use(express.static(path.join(__dirname, "public")));
  
  /* DB Connections */
  mongoose
    .connect(mongoURI, {
      // some options to deal with deprecated warning
      useCreateIndex: true,
      useNewUrlParser: true,
      useFindAndModify: false,
      useUnifiedTopology: true,
    })
    .then(() => console.log(`Mongoose connected to ${mongoURI}`))
    .catch((err) => console.log(err));

• Error Handling: In app.js, add

  /* Initialize Routes */
  app.use("/api", indexRouter);
  
  // catch 404 and forard to error handler
  app.use((req, res, next) => {
    const err = new Error("404 - Resource not found");
    next(err);
  });
  
  /* Initialize Error Handling */
  app.use((err, req, res, next) => {
    console.log("ERROR", err);
    const statusCode = err.message.split(" - ")[0];
    const message = err.message.split(" - ")[1];
    if (!isNaN(statusCode)) {
      utilsHelper.sendResponse(res, statusCode, false, null, { message }, null);
    } else {
      utilsHelper.sendResponse(
        res,
        500,
        false,
        null,
        { message: err.message },
        "Internal Server Error"
      );
    }
  });
  
  module.exports = app;

Evaluation

• Run npm run dev in the terminal
• Open your browser and test http://localhost:5000/api/messages:
• And test localhost:5000\whatever:

Good job! Back to instructions