If you’re curious about them, you can read some documentation about these events on MDN. We won’t be going over all of them because drag, dragend, dragexit, and dragstart are all fired on the element that is being dragged, and in our case, we’ll be dragging files in from our file system rather than DOM elements, so these events will never pop up. In all, there are eight events the browser fires related to drag and drop: drag, dragend, dragenter, dragexit, dragleave, dragover, dragstart, and drop.
The first thing we need to discuss is the events related to drag-and-drop because they are the driving force behind this feature. Here’s a quick look at what you’ll be making: A demonstration of a web page in which you can upload images via drag and drop, preview the images being uploaded immediately, and see the progress of the upload in a progress bar.
#Javascript click and drag plus#
This example - aside from the ES2015+ syntax, which can easily changed to ES5 syntax or transpiled by Babel - should be compatible with every evergreen browser plus IE 10 and 11. In this article, we’ll be using “vanilla” ES2015+ JavaScript (no frameworks or libraries) to complete this project, and it is assumed that you have a working knowledge of JavaScript in the browser. So, let’s actually use the APIs given to us by the browser to implement a drag-and-drop file selector and uploader. Technically, this was already possible because most (if not all) implementations of the file selection input allowed you to drag files over it to select them, but this requires you to actually show the file element. Nowadays, though, we have an even fancier way of handling file selection: drag and drop. It’s a known fact that file selection inputs are difficult to style the way developers want to, so many simply hide it and create a button that opens the file selection dialog instead.
This example should be compatible with every evergreen browser plus IE 10 and 11.
In this article, we’ll be using “vanilla” ES2015+ JavaScript (no frameworks or libraries) to complete this project, and it is assumed you have a working knowledge of JavaScript in the browser.