CODEWITHSUNDEEP
compatibilityinternet-explorer-11
Rach
Rach

Reputation: 1

Compatibility Modes for IE11 EMI and Comp

In VERY laymans terms - three questions if I can:

First, my understanding was that Comp Mode provided some rendering assistance (IE9?)- and that EMI provided the rendering further back (IE8) (along with some of the Speed enhancements) - Is this correct?

Second, it has been suggested to me that the natural progression to test compatibility would be:

I would have thought (based on my understanding) that it would be: * Native * Comp Mode * EMI

Finally, is it feasible and what is the benefit to put the website into EMI AND Comp Mode?

Upvotes: 0

Views: 436

Answers (1)

Lance Leonard
Lance Leonard

Reputation: 3285

For some users, features like enterprise IE (EMIE), compatibility view, and the other document modes are useful because they make recent versions of IE11 behave like older versions of the browser. For example, EMIE makes IE11 behave like IE8.

Why would you want this? After all IE11 supports many more standards that IE8 did. IE11 is more consistent with other browsers than IE8 was. These make it easier to create public websites that behave consistently when used by other browsers or devices.

The compatibility features, however, are meant to help those trying to maintain older applications, applications that depend on feature that IE11 no longer supports for whatever reason.

I think what you call comp mode is what MS calls compatibility view, which puts recent versions of IE into a mode similar to IE7. There are other modes available, called document modes, that put IE into modes designed to emulate earlier versions of the browser. There's a mode for each version from IE7 to IE10 as well as a mode similar to IE5 and earlier. The IE7 document mode is essentially the same as compatibility view.

The problem is that the document modes (and compatibility view) are all approximations of earlier versions. They're not perfect emulations. In many cases, they're enough to help an application work.

EMIE is a specialized mode designed to better emulate the behavior of IE8. For some companies, EMIE helps an older application run even when it doesn't run in IE8 document mode. Why? Because those apps were written based on the features and behavior supported by that version of the browser.

If you're testing applications, I would say the best approach is to run the app in whatever mode is default with the new version of IE. Use the developer tools (or even the scanner on modern.ie) to help identify problems and then update the app to work accordingly. This requires an investment of time, energy, and money that some are unwilling to make. (I would argue that this is short-sighted in the long run, but the mileage of others may vary.)

Barring that, I would use the developer tools to switch to different document modes to see if the application can be made to run until such time it can be updated. If you find a document mode that works, then you use the appropriate 'x-ua-compatible' header to enable that document mode.

If there isn't an appropriate document mode and the app worked fine in IE8, then EMIE might be a useful too. You enable that using group policies or registry keys.

There is a lot of information available to help fill in the gaps of this explanation. Here are a few to get you started:

In the end, you'll need to investigate the apps that are causing problems and determine an appropriate course of action based on the resources and priorities of your organization.

Hope this helps...

-- Lance

Upvotes: 1

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