How to communicate between iframe and the parent site?

Question

The website in the iframe isn't located in the same domain, but both are mine, and I would like to communicate between the iframe and the parent site. Is it possible?

Answer 1

With different domains, it is not possible to call methods or access the iframe's content document directly.

You have to use cross-document messaging.

parent -> iframe

For example in the top window:

myIframe.contentWindow.postMessage('hello', '*');

and in the iframe:

window.onmessage = function(e) {
    if (e.data == 'hello') {
        alert('It works!');
    }
};

iframe -> parent

For example in the top window:

window.onmessage = function(e) {
    if (e.data == 'hello') {
        alert('It works!');
    }
};

and in the iframe:

window.top.postMessage('hello', '*')

Answer 2

In 2018 and modern browsers you can send a custom event from iframe to parent window.

iframe:

var data = { foo: 'bar' }
var event = new CustomEvent('myCustomEvent', { detail: data })
window.parent.document.dispatchEvent(event)

parent:

window.document.addEventListener('myCustomEvent', handleEvent, false)
function handleEvent(e) {
  console.log(e.detail) // outputs: {foo: 'bar'}
}

PS: Of course, you can send events in opposite direction same way.

document.querySelector('#iframe_id').contentDocument.dispatchEvent(event)

Answer 3

This library supports HTML5 postMessage and legacy browsers with resize+hash https://github.com/ternarylabs/porthole

Edit: Now in 2014, IE6/7 usage is quite low, IE8 and above all support postMessage so I now suggest to just use that.

https://developer.mozilla.org/en-US/docs/Web/API/Window.postMessage

Answer 4

Use event.source.window.postMessage to send back to sender.

From Iframe

window.top.postMessage('I am Iframe', '*')
window.onmessage = (event) => {
    if (event.data === 'GOT_YOU_IFRAME') {
        console.log('Parent received successfully.')
    }
}

Then from parent say back.

window.onmessage = (event) => {
    event.source.window.postMessage('GOT_YOU_IFRAME', '*')
}

Updated:

postMessage should not work on cross domain, so the solution like this:

For example your website is: customer.com and your domain is my.com

You need to do like this

• Create a js file (upload to CDN or your server) - my.com
• Embed js file above to customer.com

Now from my.com, you can postMessage and above embed script can be received data from you.

Answer 5

After spending 2 days trying to get an iFrame posting messages back to the parent, a Vue application in my situation, I came across this excellent reference:

https://dev-bay.com/iframe-and-parent-window-postmessage-communication/

From the iframe to parent:

    const parentWindow = window.parent;
    class Message {
        constructor(type, body) {
          this.type = type;
          this.body = body;
        }
    };

    function sendMessage (windowObj, payload) {
        if(windowObj) {
          windowObj.postMessage(payload, "*");
        }
    };

    //Then call appropriately: 
    sendMessage(parentWindow, new Message("button-click", "Show Stats Overlay"));

In the parent, my Vue application mounted life cycle event, but reference the link for your own requirement:

    window.addEventListener("message", (e) => {
        var data = e.data;
        console.log("RECEIVED message from CHILD TO PARENT", data);
        
        var type = data.type;
        var body = data.body;

        if(type === "button-click" && body) {
          console.log("button-click RECEIVED FROM CHILD")
          //Additional functionality ...
        } else if (type === "text-msg" && body) {
          console.log("TEXT MESSAGE RECEIVED FROM CHILD");
          //Additional functionality ...
        }
      });

Please see reference for examples of communication from Parent to iFrame.

Hope this helps someone else.

Answer 6

the window.top property should be able to give what you need.

E.g.

alert(top.location.href)

See http://cross-browser.com/talk/inter-frame_comm.html

Answer 7

You can also use

postMessage(message, '*');