Second Introduction To Node.js

In the first line I used the http module to create an instance called http. What are modules? Node uses the CommonJs pattern to organize and load the modules. Http is a module that I have loaded. This module Node is responsible by creates a web server. There are many modules and to many things in Node (As files, data base and others). In the next article we’re going to create our own module.

For use the CommonJs pattern is need two rules: The first is that to load a module is needed using the instruction “require”. The second, I’m going to talk in the next article.

In the second instruction was created a function called “newRequest”, in which will be responsible by listen the user request and create a response. For create a response is used the variable response to create the response header and print a text to page.

In the third instruction was created the server through of instance http that calls the function “createServer” where was informed as parameter the function of listener created before.

In the last instruction, the server is raised and will be in the port 3000, the function informed as parameter is only a command that will be executed when the server is raised by the Node.

Now we are going to play with routes within of server that we created. For this, I want to create three routes: home, about and contact, below the code:

The code above is a update of the code previous and this new code is the creating of routers through of request parameter that validates the URL and prints the page desired.

With this, we created a basic web server in Node. As Node uses JavaScript, note that many times the parameter of a function it is other function. This is not common in platform as C# or Java. But as was explain in the article previous, he utilizes callback function that make with that the process do not be blocked.

You must be imagining if Node can be utilized to large systems that involve many routes and pages, since the code of today got horrible with many “ifs”. Today was a basic example, but in the next article we will utilize a web framework that will facilitate our lives.

Although today we did a basic web server in Node, the example makes clear the ease to do a web server in JavaScript. As I said above, in the next article I will pass a framework that will make our application more professional. Here I have completed the article and hope that you have understood and learned more about Node.