Add HTML5 sandbox attribute to an iframe using Javascript

Question

I\'ve got an empty iframe and a button:

Answer 1

If you want to do two things on one click event. Have a function do both of those things and fire that function on click.

window.onload = function(){
    var button = document.getElementsByName("B1")[0]
    var iframe = document.getElementsByName("IFrameName1")[0]
    button.addEventListener('click',addSandboxAndChangeLocation,false);

    function addSandboxAndChangeLocation(){
       frames['IFrameName1'].location.href='https://www.google.com/';
       iframe.sandbox = 'allow-forms allow-scripts allow-same-origin';
    }
} 

Check it out on jsFiddle!

Answer 2

While you can set the iframe.sandbox property as a string, it's technically a DOMTokenList interface, so you can also add() and remove() single tokens:

let myIframe = document.createElement('iframe');
myIframe.sandbox.add('allow-scripts');
myIframe.sandbox.toggle('allow-forms');

console.log(myIframe.sandbox.toString())
// Returns: "allow-scripts allow-forms"

console.log(myIframe.outerHTML)
// Returns: <iframe sandbox="allow-scripts allow-forms"></iframe>