The script allows you to take "screenshots" of webpages or parts of it, directly on the users browser. The screenshot is based on the DOM and as such may not be 100% accurate to the real representation as it does not make an actual screenshot, but builds the screenshot based on the information available on the page.
It does **not require any rendering from the server**, as the whole image is created on the **client's browser**. However, as it is heavily dependent on the browser, this library is *not suitable* to be used in nodejs.
It doesn't magically circumvent any browser content policy restrictions either, so rendering cross-origin content will require a [proxy](https://github.com/niklasvh/html2canvas/wiki/Proxies) to get the content to the [same origin](http://en.wikipedia.org/wiki/Same_origin_policy).
The script is still in a **very experimental state**, so I don't recommend using it in a production environment nor start building applications with it yet, as there will be still major changes made.
**Note!** These instructions are for using the current dev version of 0.5, for the latest release version (0.4.1), checkout the [old readme](https://github.com/niklasvh/html2canvas/blob/v0.4/readme.md).
The function returns a [Promise](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise) containing the `<canvas>` element. Simply add a promise fullfillment handler to the promise using `then`:
The library has two sets of tests. The first set is a number of qunit tests that check that different values parsed by browsers are correctly converted in html2canvas. To run these tests with grunt you'll need [phantomjs](http://phantomjs.org/).
The other set of tests run Firefox, Chrome and Internet Explorer with [webdriver](https://github.com/niklasvh/webdriver.js). The selenium standalone server (runs on Java) is required for these tests and can be downloaded from [here](http://code.google.com/p/selenium/downloads/list). They capture an actual screenshot from the test pages and compare the image to the screenshot created by html2canvas and calculate the percentage differences. These tests generally aren't expected to provide 100% matches, but while committing changes, these should generally not go decrease from the baseline values.
For more information and examples, please visit the [homepage](https://html2canvas.hertzen.com) or try the [test console](http://html2canvas.hertzen.com/screenshots.html).
If you wish to contribute to the project, please send the pull requests to the develop branch. Before submitting any changes, try and test that the changes work with all the support browsers. If some CSS property isn't supported or is incomplete, please create appropriate tests for it as well before submitting any code changes.
