Since many modern browsers now offer the ability to use Data URIs for more than just images, we could actually use them to essentially run a string of JS code on a page in the global namespace. How so? Here is the code for a simple
globalEval() function that can be used in modern browsers such as Chrome and FireFox:
As the jQuery docs mention, one good reason that this type of function exists is to provide a way to execute external scripts in the global namespace. It is important to reiterate that you must use this type of function sparingly, analyzing the reasons why you are using it in the first place.
Much more could be said of the uses of
globalEval() and reasons not to use
globalEval(), but I like to keep my posts short. If you do find yourself thinking you want to use
globalEval(), be sure to calculate the risks (such as possibly running malicious code if it is coming from an external source). Also, this implementation, although very simple, will not work in older browsers such as IE7 (and hasn’t been tested in IE8 or IE9). If you really need a version that has been tested for almost all browsers, I suggest using jQuery’s implementation or perhaps this one. Be careful!