Prototype and IE8 document mode

Question

I'm working with a legacy enterprise site and have a question about the current state of Magento and prototype.

Current state

I've read that when prototype 1.7 was released it resulted in issues with IE9 in Magento. At the time, to resolve this issue our developer forced all versions of IE to use IE8 document mode using:

<meta http-equiv="X-UA-Compatible" content="IE=8,chrome=1">

Additionally, prototype was downgraded to 1.6.1. This issue and solution are further documented in this issue. Further solutions for this issue are on this page (Google cache used as source site is down for maintenance).

Since then

Since this initial change, we have upgraded Magento to 1.13.x. Along the way prototype was upgraded and the site is currently using version 1.7.

What I'd like to do

I would like to restore the meta tag to the following to improve experience on IE9+:

<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">

The question

Clearly, forcing IE8 document mode is not ideal because it disallows IE9+ from displaying features it supports and results in an overall poorer experience. using IE=8 solved the issue at the time, but does this original issue still exist?

Am I able to use IE=edge with prototype 1.7?

Answer 1

The issues in IE 9 were not due to the release of Prototype 1.7. They were due to incompatibles IE 9 had with the existing versions of Prototype used by Magento at the time. The quick and easy solution was (as you noted) putting IE 9 into IE 8 mode to ensure compatibility. It was way cheaper than upgrading and/or trying to solve the issues with the core JS on old sites, so it was done very frequently.

Magento 1.13 should work in IE 1.9. Have you experienced issues that make you believe something different, or just assuming that this is so based on it using a newer version of Prototype?

We do not force IE 8 mode on any new sites we build and they work in IE 9. You should be fine using IE=edge.