Then we will cover in great detail how you can resize, crop, and do a lot with images by changing the image URL in the src attribute.We will first talk about how to do resizing purely in JavaScript using the canvas element.There are libraries like fabric.js that offer rich APIs.Īpart from the above two reasons, in almost all cases, you would want to get the resized images from the backend itself so that client doesn't have to deal with heavy processing tasks. Image manipulation in JavaScript is done using the canvas element. Imagine this with operations like undo/redo and complex text and image overlays. If a user is manipulating a heavy image, it will take a lot of time to download transformed images from the server. The speed is critical for the user in these editors. Rich image editors that work on client-sideĪ rich image editor that offers image resize, crop, rotation, zoom IN and zoom OUT capabilities often require image manipulation on the client-side.You can first resize images on the browser and then upload them to reduce upload time and improve application performance. Uploading a large file on your server will take a lot of time. Resizing images before uploading to server.However, there are a couple of situations where you might need to resize images purely using JavaScript on the client side.

This approach also saves data while transmitting images from the server to the client. You can also simulate events on a specific element.Image resizing is computationally expensive and usually done on the server-side so that right-sized image files are delivered to the client-side. trigger() simulates an event activation, complete with a synthesized event object, it does not perfectly replicate a naturally-occurring event. JQuery has the trigger method, which works like this: $(window).trigger('resize') Īlthough. ResizeEvent.initUIEvent('resize', true, false, window, 0)

This doesn't work in Internet Explorer, where you'll have to do the longhand: var resizeEvent = ('UIEvents') In your modern browsers, you can trigger the event using: window.dispatchEvent(new Event('resize'))

In this example, you can call the doALoadOfStuff function without dispatching an event. This works well if you have control over the code you want to run, but see below for cases where you don't own the code. Where possible, I prefer to call the function rather than dispatch an event.

Fire function on resize javascript