Category: Programming

So, we continue our lesson. Let us make this example a little bit more complicated by adding work with the files in the following way:

Hey all! Our topic for today is Domains.

Domains are one of the Node.js options lacking both in standard JavaScript and browser versions of JavaScript. Domains were created to catch any asynchronous errors. For instance, if we look at the server that we’ve explored in one of our previous articles (download the lesson code from here for your convenience), we will see that everything is ok when it’s working

So, whatever we type, we see the same message to be sent. Let us fix it. We send messages with a POST method. In order to read this method from req, we need to work with it as with a stream. So, let us look at the following scheme that describes a request’s lifecycle, in particular of the req and res objects.

Hey all! The aim of our lesson for today is to learn how to create a Node.js chat. Our first chat will be rather simple.

Upon the file ending you will see the end event, in the handler of which we will end our response by calling res.end. Thus, the outgoing connection will be closed for the file has been completely sent. The resulting code is quite versatile:

Our next step will be using the streams to work with network connections. And we will start from delivering files to a visitor. As you may remember, we’ve already had a task like this: if a visitor requires the following url, you will give him the file. Let us create a file pipe.js with the following code (for your convenience, you can download code’ lesson from the repository because we’ll need an HTML file from there):

Hey all! Our topic for today is Data Streams In Node.js. We will try to learn all the aspects in details for the reason it turns out that on the one hand, common browser JavaScript development lack streams. And on the other hand, knowing and understanding stream principles is necessary for seamless server development because a stream is a versatile way of work with data sources universally used.

This article will deal with how to create a web server in Node.js, which will return a file to a user from a public directory. You may wonder: why do we need Node.js here? Why can’t we use another server? You question surely does make sense. Yes, for returning files other servers are generally more effective. From the other side, Node.js works pretty well, too. Second, before returning a file it can also perform some intellectual activities: for example, refer to a database, check out whether a user is permitted to access the file and give the file to him, if it’s permitted.

Dear friends! The key goal of our today’s lesson is to learn how to work with binary data and file system. Node.js contains fs module to work with files, which includes a number of functions for various operations with files and directories.

Our next lesson is devoted to Node.JS debugging. First of all, we will explore the simplest built-in debugger that is called by the node debug command. It looks just like that. Imagine, we’ve got the script: