Lab Week09 Boilerplate
In the lab exercise, there were some confusing points about api.js and app.js. This boilerplate (template) complicates a few things, but also cleans up a few things.
Structure
server.js (New file)
The sole purpose of this file is to run the app. So we specify in our package.json that to run our project, do node server. We have this as a separate file from app.js because we want to be able to test app.js (without leaving any open processes hanging after the tests). For more info see "Seperate you app and server" in this article: http://www.albertgao.xyz/2017/05/24/how-to-test-expressjs-with-jest-and-supertest/
app.js
This file now defines the Express "app" and is responsible for taking requests and dealing with them. We also introduce the app.use(...) function that allows us to define routes in another file and redirect the queries to that file, see
const express = require("express");
const app = express();
const api = require("./src/api.js");
app.use("/api", api);
...We are saying that any request to "/api" should be handled by the api.js file. Note that this changes our API endpoint to use /api/greeting/some_name (not simply /greeting/some_name).
src/api.js
Here we no longer create an Express app, but create a new express Router and define what that router should handle. This is the logic that our update app.js now uses.
Here you will need to make some changes to get the URL [localhost:3000/api/greeting/Diana][http://localhost:3000/api/greeting/Diana] return an object (in JSON) that looks like
{
"greeting": "Hello Diana!"
}