is-cross-origin
v1.0.1
Published
tells whether provided window is cross origin or same origin
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is-cross-origin
a simple API for telling whether a window is cross origin or same origin
install
yarn add is-cross-origin / npm install is-cross-origin
usage
the API should be provided with one/two arguments, both windows. the first is a destination window to test its origin in relation to a source window, and the second is that source window. second argument is optional, and will be set to current window in case not provided.
const isCrossOrigin = require('is-cross-origin');
const result = isCrossOrigin(dstWindow, srcWindow);
if (result) {
console.log('destination window ', dstWindow, ' is in a cross origin in relation to source window ', srcWindow);
} else {
console.log('destination window ', dstWindow, ' is in the same origin as the source window ', srcWindow);
}so for example, in order to tell whether a certain iframe is in a cross origin in relation to the current window, this should do the trick:
<html>
<head></head>
<body>
<iframe id="a" src="/"></iframe>
<iframe id="b" src="//cross-origin.com"></iframe>
<script>
window.onload = function() {
const aIsCrossOrigin = isCrossOrigin(a.contentWindow /*, window*/);
const bIsCrossOrigin = isCrossOrigin(b.contentWindow /*, window*/);
console.log('is "a" cross origin? ' + aIsCrossOrigin); // false
console.log('is "b" cross origin? ' + bIsCrossOrigin); // true
}
</script>
</body>
</html>usage update
now a third argument can be passed that will be the Object constructor to use when telling whether provided arguments are of type windows or not (default will evaluate to window.Object:
isCrossOrigin(dstWindow, srcWindow, window.Object /* optional */)important usage notes
- window should finish loading in order for this API to work.
if the API is provided with a window that did not finish loading, it will return
falseregardless of whether the iframe is cross origin or not. to avoid that, call the API with windows that finished loading by usingonloadevent handler or something similar.