Basarat Ali Syed - Beginning Node.js

CHAPTER 1

Setting Up for Node.js Development

In this chapter, we discuss how to set up a Node.js development environment as we guide you through the installation process of Node.js on various platforms. Then we give you a tour of the Node.js REPL (read-evaluate-print-loop) and show you how you can run Node.js applications. Finally, we provide examples of Integrated Development Environments (IDEs) that can help you deliver applications faster and make your journey more enjoyable.

Installing Node.js

You no longer need to build Node.js from source in order to develop Node.js applications. Node.js now provides installers for Windows as well as Mac OS X, and it can be installed in the same way as any other application on these platforms (.

In the next section, we will guide you through the important steps for your operating system (OS). You can safely skip the section not relevant to your current OS.

Installing on Windows

The website for Node.js lists Windows Binary ( .exe ) and Windows Installer (.msi). You do not want to use the windows binary ( .exe ) for development, as it does not contain important things such as Node Package Manager (NPM)).

. Node.js Setup Wizard on Windows

We recommend that you install to the default directory and with the default options when starting out for the first time. It is especially important that you let the installer Add to PATH ().

. Default options for Node.js installer on Windows

After installation, uninstalling and reinstalling Node.js are extremely easy. If you run the installer again, you will be prompted with the Remove option, as shown in .

. Node.js uninstaller for Windows

Since the installer set up the system PATH, you can run Node.js from the command prompt (search for command prompt in the Windows start menu). We can start up Node.js by simply typing node in cmd (). This puts you in the REPL, which we explain in the next section.

. Running Node.js from the command line

Installing on Mac OS X

Download the Mac OS X installer provided by the Node.js team from ).

. Node.js Installer for Mac OS X

When starting out, stick with the defaults and install for all users ().

. Node.js setup for all users option

Once complete, the installer will inform you of the two binaries it installed ( node and npm ), as shown in .

. Node.js binaries installed

We will cover npm extensively in ). For Mac OS X, you can start node from Terminal (use Mac OS X spotlight to search for Terminal). If you execute node in Terminal, it will start the Node.js REPL, which we discuss next.

. Running Node.js from the command line on Mac OS X

Using the REPL

Node.js provides you with a REPL, type .help and press Enter.

. Node.js REPL help

You can execute arbitrary JavaScript in the REPL and see its result immediately, as shown in .

in the Node.js REPL

At each step, the REPL prints the outcome of the last statement executed. The REPL does not execute your input code until all brackets have been balanced. To execute multiple lines, simply wrap them in parentheses. The REPL uses () to denote that it is waiting for the complete code before executing. Simply close the parentheses and press Enter for the REPL to evaluate the entered JavaScript (see ). To exit from inside a block (...) without executing what you have already entered, simply type .break or press Ctrl+C.

. Executing multiple lines in the Node.js REPL

The REPL is great when you want to test some JavaScript and make sure that it functions the way you want it to. You can exit the REPL by typing .exit (or by pressing Ctrl+D).

Executing Node.js Scripts

We have seen how to execute JavaScript by typing it into the REPL. However, you will most commonly be writing Node.js programs (script files) and execute them with Node.js. You can execute a JavaScript source file in Node.js by simply passing the file to node on the command line (.

. Executing a script file in Node.js

. helloworld.js

Then run the file by running node helloworld.js on the command line from the same directory that you saved the file ( C:\ , in our case).

Notice that we use console.log in the same way as we would use if we were doing front-end web development. One of the philosophies of Node.js is that it should be intuitive to front-end developers. The Node.js team has tried to keep the API consistent with the browser whenever it made sense.

Node.js simply executes the input JavaScript from top to bottom as a browser would. It is, however, conventional to name the main file of your application app.js so people know which file to execute in order to run your application.

Setting Up an Integrated Development Environment

Node.js is great because it is really simple to get started with just a text editor and Terminal. (That does not mean that there arent more full-featured development environments out there.) Node.js has seen fantastic support from JetBrains (creators of IntelliJ Idea, RubyMine, and PyCharm) in the form of WebStorm as well as from Microsoft in their Visual Studio. WebStorm is available on Windows, Mac OS X, and Linux, whereas Visual Studio is available for Windows only.

WebStorm Node.js Support

WebStorm claims to be the smartest JavaScript IDE. It is based on IntelliJ IDEA platform and might be easy for you to migrate to if you are coming from a Java, Ruby, or Python background. You can get it from http://www.jetbrains.com/webstorm/ .