Fun Friday NodeJS

• 7e9b711 Initial layout

  Just a few files to initialize the git repository and to begin the workshop.

• dcee3ca Basics

  This commit shows how to write and start code (node helloWorld.js) with NodeJS.

• 56dd7f9 Synchronous commands

  We showed how to do basic scripting with synchronous commands. We wrote and read files with writeFileSync and readFileSync. As we had files and wanted to add new data to them, we used appendFileSync.

• 7faef0d Asynchronous / event-driven

  To be able to use non-blocking functions, we need to register callbacks. This differs a bit from regular imperative programming and you need to "look around" for your code or start having a "callback hell".

• 0b75ffb Basic modules

  The biggest plus in Node is the very easy to use module system. You can easily structure your code by using require(). We had a look at how to write our own little module in calculator.js and how to use it in helloWorld.js.

• 024515d A basic Webserver example

  We had a look at express in server.js and have seen how to use the very simple API of Express. We had to register a middleware to process a request and put a small static server for all other files in place. Then we started the server on port 8080 and tried out our basic routes: / (or /index.html) and /hello.

• 9806869 More Express

  There are actually two examples in this commit. First, we set up a router (namely helloRouter) that routes anything below /hello. Then we had a look at multiple routes that match a specific path (/hello/olli). We figured out that the order of the registration of the routes is critical: The first one that matches wins.

• 0b0ceb0 Using handlebars templates

  With handlebars, we use template strings that contain {{variable}} instructions. Handlebars replaces these strings with the contents of the specified variable. Using Handlebars.compile(), we receive a function where we pass the contents of the variables. As the compilation may take some time, we had a look at how we could cache the compiled templates. Using setTimeout, we mocked a long running asynchronous operation to get the template and had a look what happened if this produced an error.

• f96ae32 Error handling and using npm to start our server

  A four parameter function as middleware handles errors in express. We had a look at when we had to register them and what the next(err) method means while doing error handling. After the workshop, we put server.js in package.json which basically means we can run the server we wrote by writing npm start now.