Building the Question Routes

Let's start by creating a module to handle the routes. 0:01 First we'll create a new file and save it to the root folder as routes.js. 0:04 At the top of the file don't forget to put use strict. 0:11 Now let's bring in Express in requiring the Express package. 0:19 var express = require("express"). 0:25 Then we can setup a new router. 0:35 You can read more about the express router in the teacher's notes. 0:39 The router object is what we'll pass into the main app. 0:49 To do this at the bottom of the file we'll export the router. 0:52 Let's save that and move back to the app.js file to connect the two together. 1:06 Underneath these two dependencies, 1:13 let's bring in the router module that we created. 1:16 Let's use the variable routes. 1:28 And require our routes file. 1:33 Routes can be connected to the app in the same way as middleware 1:48 using the use method. 1:53 We only want the router to kick in when any route starts with /questions. 2:01 So we'll pass in the string /questions as the first parameter. 2:08 When a request comes in for 2:15 any route that starts with questions they will be ushered into the routs module. 2:17 The routes module will try to apply one of the handlers were trying to code. 2:21 Let's switch back to the routes J.S. file. 2:26 Let's build a fast route handler. 2:30 The first route is slash questions with the get verb 2:33 one the router objects we can call the get method. 2:38 The first parameter will be the rank string that we want to handle. 2:48 Inside this particular router this will be represented by a single slash. 2:54 That's because the app handles the request to the router. 2:59 It strips away what was already matched /questions. 3:03 So any sub routes to questions would be built onto the slash. 3:14 For example If 3:20 the app gets a request to /questions/5/answers 3:25 it would see that the URL meets the criteria for 3:32 our router and it gets handed The route. 3:38 /5/answers. 3:48 The second parameter in this method is a callback function. 3:54 This is our route handler. 4:04 It will execute when a request comes in that matches the route and verb. 4:07 When the handler is called, it will receive the request and response subject 4:15 which we'll abbreviate to (rec, 4:20 res). 4:25 And we want this route to // Return all the questions. 4:28 Notice that this function looks a lot like middleware 4:36 without the next function as the third parameter. 4:39 It works in the same way and we could have put the next in. 4:42 But because this is likely to be the last stop in our application before 4:47 the response is sent back to the client, we wouldn't need the next function now. 4:51 We will use it in future videos as it can help us handle errors. 4:55 To handle this request to read all questions we would need to 4:59 talk to a database and we haven't set up a connection yet. 5:04 We'll need the database connection for all these routes eventually but for 5:09 now let's send some hard coded responses from them to see the API working. 5:14 To send a json response to the clients we'll use their responses json method. 5:25 This call will end the life cycle of the request process, 5:35 we can put javascript objects into the jsson method. 5:39 And it will take care of the serializing and 5:43 the stringifying of the json before sending it out. 5:45 Let's follow the same 5:57 pattern to handle 6:03 post requests using 6:08 post instead of get. 6:14 We'll include one more property to send back the data we 6:52 received as an extra check that we're able to access the data. 6:55 Now we can create the route for retrieving specific questions. 7:06 We'll use the ID parameter to represent the question ID portion of the route. 7:10 We can update the response so it says for a specific ID. 7:42 Now when we test these we should see the results in Postman rather than 7:55 the terminal. 7:59 Let's save the file. 8:01 Stop the server. 8:06 Switch over to Postman. 8:09 Create a GET request on localhost/questions and click Send. 8:12 You should see a json response showing up in postman's response window, 8:23 now we'll send a POST request To localhost:3000/questions. 8:31 For the body you may already have the json from our last POST 8:42 request we made, but if not puts it back in. 8:46 Hit Send. 8:52 And you should see the response we expected with a reference to the json 8:57 we sent. 9:02 Finally let's test localhost:3000/questions/89 9:07 with a GET request to verify if we can see the ID in the response. 9:14 It works, great job. 9:24 Let's take a peek in the terminal and 9:26 as you can see there's not much happening there. 9:29 We've got the notification that the express server has started but 9:32 nothing after that it would be nice to see some 9:35 information about the requests in the API, and its responses while we're developing. 9:38 In the next video will add locking functionality that build and 9:44 test the rest of our routes. 9:48