Author: saqibkhan
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HTTP Methods
The HTTP method is supplied in the request and specifies the operation that the client has requested. The following table summarizes the commonly used HTTP methods. Sr.No. Method & Description 1 GETThe GET method requests a representation of the specified resource. Requests using GET should only retrieve data and should have no other effect. 2…
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URL Building
We can now define routes; they are either static or fixed. To use dynamic routes, we need to provide different types of routes. Using dynamic routes allow us to pass parameters and process based on them. Following is an example of a dynamic route. To test this go to https://localhost:3000/123. You will get the following response.…
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Routing
Web frameworks provide resources such as HTML pages, scripts, images, etc. at different routes. Koa does not support routes in the core module. We need to use the Koa-router module to easily create routes in Koa. Install this module using the following command. Now that we have Koa-router installed, let’s look at a simple GET…
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Generators
One of the most exciting new features of JavaScript ES6 is a new breed of function, called a generator. Before generators, the whole script was used to usually execute in a top to bottom order, without an easy way to stop code execution and resuming with the same stack later. Generators are functions which can…
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Hello World
Once we have set up the development, it is time to start developing our first app using Koa. Create a new file called app.js and type the following in it. Save the file, go to your terminal and type. This will start the server. To test this app, open your browser and go to https://localhost:3000 and you should receive…
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Environment
To get started with developing using the Koa framework, you need to have Node and npm (node package manager) installed. If you don’t already have these, head over to Node setup to install node on your local system. Confirm that node and npm are installed by running the following commands in your terminal. You should receive an…
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Overview
What is Koa? Koa provides a minimal interface to build applications. It is a very small framework (600 LoC) which provides the required tools to build apps and is quite flexible. There are numerous modules available on npm for Koa, which can be directly plugged into it. Koa can be thought of as the core…
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WebSockets
For real-time communication, you can use WebSockets with the ws library or socket.io. a. Install Socket.IO b. Set Up Socket.IO In app.js:
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File Uploads
Handle file uploads using middleware like multer. a. Install Multer b. Configure Multer In app.js: Here, dest specifies the directory where files will be stored, and upload.single(‘file’) handles single file uploads.
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Security
Securing your Express application is crucial to prevent common vulnerabilities. Here are some best practices and tools to help with that. a. Helmet Helmet helps secure your Express apps by setting various HTTP headers. In your app.js: b. Rate Limiting Limit the number of requests from a single IP to prevent abuse. In your app.js:…