CODEWITHSUNDEEP
javascriptecmascript-6promise
cwtuan
cwtuan

Reputation: 1861

Elegant way to include es6-promise for IE

Since Promise is not support in all IE versions, I would like to make the IE users to download a pollyfill in HTML.

<!--[if IE]>
<script src="//cdnjs.cloudflare.com/ajax/libs/es6-promise/4.1.1/es6-promise.min.js"></script>
<![endif]-->

However, conditional comments are not supported in IE 10 and 11. So the above code doesn't work in IE 10 and 11.

Then, Microsoft provide a workaround.

<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE9">

This make IE 10 and 11 behave like IE 9.

But my website work only in IE 10+. So this solution isn't suitable to me. Is there any other way to solve this issue?

Upvotes: 2

Views: 7661

Answers (2)

TeamEASI.com
TeamEASI.com

Reputation: 86

Same without the external script

var lPromise = function(handler) {
  if (typeof Promise === "function")
    return new Promise(handler);
  var self = this;
  self._handler = handler;
  this.then = function(onFulfilled, onRejected) {
    this._handler(onFulfilled, onRejected);
  }
  return self;
}
this.Promise = function(handler) {
  return new lPromise(handler);
}

Upvotes: 1

Bergi
Bergi

Reputation: 665130

Just use

<script>
    if (typeof Promise !== "function")
        document.write('<script src="//cdnjs.cloudflare.com/ajax/libs/es6-promise/4.1.1/es6-promise.min.js"><\/script>');
</script>

which does not work only for IE users, but in every environment without a native Promise implementation.

Upvotes: 10

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