Friday, September 2, 2011

Can you tell me more about eValid's architecture?

An eValid user wrote:

Can you tell me more about eValid's architecture? Is it based on the Trident Rendering Engine?

Yes, the browsing part of eValid is based on use of the MSHTML (Trident Rendering Engine) libraries.

Although this makes eValid a complete browser (which emulates behavior of whatever version of IE you have installed on your machine), there are a few differences in the way eValid interacts with MSHTML. The main difference is that eValid has direct, immediate, "in-memory" access to the browser DOM and this unique capability makes much of what eValid does possible.

That architecture -- incorporating direct DOM access in a free-standing executable -- also is the reason why we can use eValid in server loading work by running multiple (100's or 1,000's of) instances to impose completely realistic load.

Also -- and this fact may be just as important -- the eValid engine does not make use of the JavaScript interpreter that is part of the browser. That is important because it means that applications that rely on JavaScript like modern RIA's that use AJAX do not experience any interference in their operation from the test engine itself. (You would not want a test engine to interfere with it is supposed to test, would you?)