Compiled Learning Objectives

At the end of the sprint, you should be able to do the following things. Make sure to check you can do them all, and if not, go back and keep practicing until you can.

WebSockets

• Stream live updates from a server using WebSockets.
• Discuss the trade-offs of using WebSockets or polling.
• Describe properties of message formats (e.g. including a command name).

Adding like/dislike

• Identify what data needs to be stored and exchanged between a client and server.
• Devise a scheme for differentiating messages with different meanings (e.g. a new message vs a new like).
• Contrast giving updated values as absolute values or relative changes.
• Implement an end-to-end feature involving data updates and reconciliation across a client and server.

Identifying common functionality

• Identify and explain the risks and costs of duplicate code.
• Identify which code is equivalent, equivalent with parameters, or unique.

Extracting common functionality

• Extract functionality used by multiple route handlers into a common function.

Continuation styles

• Compare different approaches to choosing how to handle potential request errors.

Extracting a middleware

• Identify and explain the risks and costs of manually calling code (e.g. authentication validators/extractors) from multiple route handlers.
• Explain the middleware pattern.
• Implement and wire up a middleware with Express.

Using existing middleware

• Use an existing middleware with Express.

Explaining code workshop

• Make a strategy for how to explain code.
• Explain the big picture (what not how) of a software system.
• Explain how functions and lines of code in a software system work.

Discussion: Continuation styles

• Compare different approaches to choosing how to handle potential request errors.
• Understand why other people may have different preferences to you.