# when-dom-ready
> $(document).ready() for the 21st century
[](https://travis-ci.org/lukechilds/when-dom-ready)
[](https://coveralls.io/github/lukechilds/when-dom-ready?branch=master)
[](https://www.npmjs.com/package/when-dom-ready)
Returns a Promise for cleaner usage, provides a Promise chain helper function and can also be used as a pure function. The Promise will resolve instantly if the DOM is already ready.
## Browser Compatibility
- IE9+ (requires Promise polyfill)
- Edge *
- Firefox 29+
- Safari 8+
- Chrome 33+
- Opera 23+
## Install
```shell
npm install --save when-dom-ready
```
or for quick testing:
```html
< script src = "https://unpkg.com/when-dom-ready" > < / script >
```
## Usage
```js
import whenDomReady from 'when-dom-ready';
whenDomReady().then(() => console.log('DOM is ready yo!'));
```
You can still use callbacks if you want to:
```js
whenDomReady(() => console.log('DOM is ready yo!'));
```
## Promise chain helper
There is also a little helper function, `whenDomReady.resume()` , that pauses the execution of a Promise chain and then resumes it with the last value once the DOM is ready.
This allows you to specify complex async control flow in simple readable code:
```js
fetch('/my-badass-api.json')
.then(getSomeProcessingDoneWhileWaitingForDom)
.then(whenDomReady.resume())
.then(injectDataIntoDom);
```
## Pure usage
You can make the function pure by passing in a `document` object. This is really [useful for tests ](https://github.com/lukechilds/when-dom-ready/blob/master/test/unit.js ) and mocking environments.
For example this works in Node.js:
```js
const jsdom = require('jsdom');
const whenDomReady = require('when-dom-ready');
const doc = jsdom.jsdom('').defaultView.document;
whenDomReady(doc).then(() => console.log('DOM is ready yo!'));
```
Again, you can use the callback version as a pure function too:
```js
whenDomReady(() => console.log('DOM is ready yo!'), doc);
```
And of course the helper:
```js
//...
.then(whenDomReady.resume(doc))
```
## License
MIT © Luke Childs
