Copying text to the clipboard shouldn't be hard. It shouldn't require dozens of steps to configure or hundreds of KBs to load. But most of all, it shouldn't depend on Flash or any bloated framework.
First, include the script located on the `dist` folder or load it from [a third-party CDN provider](https://github.com/zenorocha/clipboard.js/wiki/CDN-Providers).
Now, you need to instantiate it by [passing a DOM selector](https://github.com/zenorocha/clipboard.js/blob/master/demo/constructor-selector.html#L18), [HTML element](https://github.com/zenorocha/clipboard.js/blob/master/demo/constructor-node.html#L16-L17), or [list of HTML elements](https://github.com/zenorocha/clipboard.js/blob/master/demo/constructor-nodelist.html#L18-L19).
Internally, we need to fetch all elements that matches with your selector and attach event listeners for each one. But guess what? If you have hundreds of matches, this operation can consume a lot of memory.
For this reason we use [event delegation](https://stackoverflow.com/questions/1687296/what-is-dom-event-delegation) which replaces multiple event listeners with just a single listener. After all, [#perfmatters](https://twitter.com/hashtag/perfmatters).
We're living a _declarative renaissance_, that's why we decided to take advantage of [HTML5 data attributes](https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Using_data_attributes) for better usability.
A pretty common use case is to copy content from another element. You can do that by adding a `data-clipboard-target` attribute in your trigger element.
Truth is, you don't even need another element to copy its content from. You can just include a `data-clipboard-text` attribute in your trigger element.
The tooltips you see on the [demo site](https://clipboardjs.com/) were built using [GitHub's Primer](https://primer.style/css/components/tooltips). You may want to check that out if you're looking for a similar look and feel.
If you don't want to modify your HTML, there's a pretty handy imperative API for you to use. All you need to do is declare a function, do your thing, and return a value.
For instance, if you want to dynamically set a `target`, you'll need to return a Node.
Also, if you are working with single page apps, you may want to manage the lifecycle of the DOM more precisely. Here's how you clean up the events and objects that we create.
This library relies on both [Selection](https://developer.mozilla.org/en-US/docs/Web/API/Selection) and [execCommand](https://developer.mozilla.org/en-US/docs/Web/API/Document/execCommand) APIs. The first one is [supported by all browsers](https://caniuse.com/#search=selection) while the second one is supported in the following browsers.
The good news is that clipboard.js gracefully degrades if you need to support older browsers. All you have to do is show a tooltip saying `Copied!` when `success` event is called and `Press Ctrl+C to copy` when `error` event is called because the text is already selected.
A browser extension that adds a "copy to clipboard" button to every code block on _GitHub, MDN, Gist, StackOverflow, StackExchange, npm, and even Medium._
Install for [Chrome](https://chrome.google.com/webstore/detail/codecopy/fkbfebkcoelajmhanocgppanfoojcdmg) and [Firefox](https://addons.mozilla.org/en-US/firefox/addon/codecopy/).