Do you know: Server-side rendered web apps, JSON APIs, and microservices can also be developed with Express JS?
Concepts of Node.JS
Dealing with Express provides us with the tools we need to accomplish different stages with a minimal amount of code. The following are the three main ideas that Express deals with:
Routing:
The goal of routing is to specify what code must be executed in reaction to a request that the site has received. The conventional approach for doing this is to use the request’s HTTP Method in tandem with the URL trend.
Express.Router( [options] )
To construct a fresh router object, use the Express.Router() function, you can even use it to build a new router object for your program’s request handling.
The Express.JS Router() method will help you simply distinguish between distinct requests.
The subsequent important aspect is the Middleware-
Middleware:
The next procedure in an app’s request-response loop is accessed by middleware methods, which have accessibility to the demand object (req), the response object (res), or both.
Middleware is a type of program that runs at some point during the request-response chain and is frequently used to enhance the functioning of web servers.
Procedures with access to the Request and Response variables are known as middleware.
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Depending on the stacking order of the middleware, it can run any obfuscated code and is performed once at a time.
Request/Response:
Interacting with Node JS Express and other Node.JS server FrameWorks will expose you to abbreviations like req and res.
Both the Request that the server receives and the Response that you will finally send are represented by them.
Both the Request and Response objects are used as callback function parameters by both Express.JS and Node.JS.
You have access to the request’s headers, cookies, body, and query parameters. It has the ability to overwrite any value or item there.
Though to make it clear- the output to the browser will not be impacted by overwriting headers or cookies.
Express Installation
Express can be installed and used using the Node Package Manager. Running the next command line will accomplish this.
npm install Express
The aforementioned command asks the Node package management to download and install the necessary Express modules.