I want to be able to control iframe based YouTube players. This players will be already in the HTML, but I want to control them via the JavaScript API.
I\'ve been re
Thank you Rob W for your answer.
I have been using this within a Cordova application to avoid having to load the API and so that I can easily control iframes which are loaded dynamically.
I always wanted the ability to be able to extract information from the iframe, such as the state (getPlayerState) and the time (getCurrentTime).
Rob W helped highlight how the API works using postMessage, but of course this only sends information in one direction, from our web page into the iframe. Accessing the getters requires us to listen for messages posted back to us from the iframe.
It took me some time to figure out how to tweak Rob W's answer to activate and listen to the messages returned by the iframe. I basically searched through the source code within the YouTube iframe until I found the code responsible for sending and receiving messages.
The key was changing the 'event' to 'listening', this basically gave access to all the methods which were designed to return values.
Below is my solution, please note that I have switched to 'listening' only when getters are requested, you can tweak the condition to include extra methods.
Note further that you can view all messages sent from the iframe by adding a console.log(e) to the window.onmessage. You will notice that once listening is activated you will receive constant updates which include the current time of the video. Calling getters such as getPlayerState will activate these constant updates but will only send a message involving the video state when the state has changed.
function callPlayer(iframe, func, args) {
iframe=document.getElementById(iframe);
var event = "command";
if(func.indexOf('get')>-1){
event = "listening";
}
if ( iframe&&iframe.src.indexOf('youtube.com/embed') !== -1) {
iframe.contentWindow.postMessage( JSON.stringify({
'event': event,
'func': func,
'args': args || []
}), '*');
}
}
window.onmessage = function(e){
var data = JSON.parse(e.data);
data = data.info;
if(data.currentTime){
console.log("The current time is "+data.currentTime);
}
if(data.playerState){
console.log("The player state is "+data.playerState);
}
}