Last week, Microsoft officially launched the first preview of Internet Explorer 11 with Windows 8.1. In this way, it's time to rest on all the rumors about this controversial leaked version of the web browser. We now know some important details about Internet Explorer 11, including support for WebGL, prefetch (Translator's note: preread, such as uploading files, etc., and I don't know if the translation is correct), prerender (preprepresentation), flexbox, mutation observers and other web standards. Perhaps more interesting in IE11 is whether it is IE.
Microsoft has removed some features from the Internet Explorer browser for the first time in a long time. The user-agent string has also changed. It seems that Microsoft has abandoned its own way so that existing IE-detecting code branches will return false in Internet Explorer 11 browser, whether in JavaScript or on the server.
Changes to User-agent
Compared with previous versions, Internet Explorer 11's user-agent string is shorter, and there are some interesting changes:
Mozilla/5.0 (Windows NT 6.3; Trident/7.0; rv 11.0) like Gecko
For user-agent strings for Internet Explorer 10 on Windows 7
Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/6.0)
The most obvious difference is that the "MSIE" tag of the user-agent string in the Internet Explorer browser has been removed. Also compelling is the addition of "like Gecko" to the tail of the user-agent. This shows that Internet Explorer would rather be recognized as a Gecko browser than as an Internet Explorer itself. Safari is the first browser to add "like Gecko", so that anyone can sniff the "Gecko" character in the user-agent string to allow the browser to pass.
Now any sniffing code that looks for "MSIE" does not work under the new user-agent string. You can still search for the "Trident" character to determine that it is the IE browser (the "Trident" logo was introduced with Internet Explorer). The real version of Internet Explorer is identified by "rv".
In addition, the information of the navigator object has also changed, which further conceals the browser being used.
Set to "Netscape"
Set to "Gecko"
This may seem like an attempt to sneakily trick the developer, but these are actually HTML5 specified. The attribute must be "Gecko", and it should also be "Netscape" or more specific. But Internet Explorer 11 lacks follow this weird suggestion.
Side effects caused by changes in navigator information, browser detection based on Javascript logic in use may not be available, resulting in Internet Explorer 11 recognizing as a Gecko-based browser.
With his friends
Since IE4, it has been omnipotent in the IE browser. The () implemented earlier is similar to the IE method of obtaining a DOM element reference. Although DOM support has been maintained from IE5 to IE10. However, in 11, the product left over from this era has been set to return false, which means that any code-based branch judgment will fail in IE11, even if the code actually works properly.
Another legacy is the attachEvent() that adds the event function, similar to the detachEvent() method. This method has been removed from IE11. These methods are removed to avoid some logical judgments, such as:
function addEvent(element, type, handler) {
if () {
("on" + type, handler);
} else if () {
(type, handler, false);
}
}
Of course, we recommend that the version you are best used to test is always stable and meet the standards. On some level, removing the attachEvent method does not cause any discomfort. However, the Internet is full of feature detection logic codes for the Internet. The removal of the attachEvent method ensures that any code written in the above manner will use the standard version instead of IE-specific methods.
Some other removed features:
()——IE version of eval() method
()——Scrolling method of IE window
——The status changes of the loading script in IE
——The status of script loading in IE
——The currently selected text in IE
——Create style sheet text in IE
——The style object that references a style sheet in IE browser
All of these IE browser methods are replaced by standard features. After removing these features and methods, the cross-browser code based on standard functional feature detection can still function normally without changing.
in conclusion
IE11 is probably the best IE browser for a long time. Microsoft is finally preparing to eliminate mistakes made in the past and is ready to start with browsers based on current standards. Deleting old features and modifying user agent strings that are not recognized as IE browsers is a unique practice, which ensures that all websites continue to work. If the web application uses feature detection instead of browser sniffing, the code should be run in IE11. For applications that use user-agent sniffing, users can still see a website with good functionality, because IE11 has excellent support for standard.
A future without IE branch code is coming, let's look forward to it together.
(Updated on July 2, 2013), the revision mentioned was not actually deleted, but changed to falsesy
Haven't translated an article for a long time，This time the translation is Nicholas C. ZakasBig bull'sBlog，
The original text is here：/blog/2013/07/02/internet-explorer-11-dont-call-me-ie/