Lesson 4: Middleware, REST Methods, and Postman

Tutorial Video from 6:10:46 to the end of the video.

Students finish the Express tutorial they started last week. You should expect the following modules to be completed in the 02-express-tutorial directory:

08-middleware-basic.js
09-middleware-use.js
10-middleware-options.js
11-methods.js
12-route-app.js
routes/people.js
routes/auth.js
controllers/people.js
authorize.js (used in file 9)
logger.js (used in file 8 and file 9)

Additional Assignment: Practice Middleware

This additional assignment is found in practice-middleware.js, and it is not part of the video tutorial. Make sure it’s completed! Also, give it a closer look, since students are applying their knowledge from instructions rather than rote following, so there’s a chance that there will be an opportunity to provide more meaningful feedback.

Hard Parts

Help the students to understand the different ways that middleware can be called in Express (global app.use, on a group of sub-routes, or even on a specific path). Also check that they understand the importance of the order of middleware and that the request will be handed off to each middleware until a response is sent or the pipeline is halted.

Students sometimes struggle with the way we’re using and passing around callbacks here so if needed, you can refer them back to some of the work in the first two weeks that covers that at a lower level. We also begin using arrow functions more liberally here so it’s possible that’ll be new to some students. A common gotcha is not leaving the res.send (or other response-rendering call) as the last line in a route method, without an explicit return keyword.