svgedit/archive/untested-extensions/ext-xdomain-messaging/ext-xdomain-messaging.js

50 lines
1.8 KiB
JavaScript

/**
* Should not be needed for same domain control (just call via child frame),
* but an API common for cross-domain and same domain use can be found
* in embedapi.js with a demo at embedapi.html.
*/
export default {
name: 'xdomain-messaging',
init () {
const svgEditor = this;
const { svgCanvas } = svgEditor;
try {
window.addEventListener('message', function (e) {
// We accept and post strings for the sake of IE9 support
if (!e.data || ![ 'string', 'object' ].includes(typeof e.data) || e.data.charAt() === '|') {
return;
}
const data = typeof e.data === 'object' ? e.data : JSON.parse(e.data);
if (!data || typeof data !== 'object' || data.namespace !== 'svgCanvas') {
return;
}
// The default is not to allow any origins, including even the same domain or
// if run on a `file:///` URL. See `svgedit-config-es.js` for an example of how
// to configure
const { allowedOrigins } = svgEditor.configObj.curConfig;
if (!allowedOrigins.includes('*') && !allowedOrigins.includes(e.origin)) {
console.warn(`Origin ${e.origin} not whitelisted for posting to ${window.origin}`);
return;
}
const cbid = data.id;
const { name, args } = data;
const message = {
namespace: 'svg-edit',
id: cbid
};
try {
// Now that we know the origin is trusted, we perform otherwise
// unsafe arbitrary canvas method execution
message.result = svgCanvas[name](...args); // lgtm [js/remote-property-injection]
} catch (err) {
message.error = err.message;
}
e.source.postMessage(JSON.stringify(message), '*');
});
} catch (err) {
console.error('Error with xdomain message listener: ' + err);
}
}
};