Question

I was wondering if there are any methods to check if a website is successfully displayed or rendered on the a user’s system.

The application of this is to to deliver a content if and only if it is a real user rather than a crawler/spider fetching the content.

so the check would be:
-check if the content is rendered/displayed,
-execute the next script
-otherwise
-do something else

any help is highly appreciated.
Cheers

Answer 1

Most crawlers simply do not execute any JavaScript, but you cannot really rely on that since it’s easy to imagine a sophisticated company creating a search engine that actually does mimic a JS-enabled browser. Many crawlers have an easily identifiable user-agent string, but you cannot rely on that either.

You could do something, I suppose, like attempt to poll for the mouse x,y position a couple of times, looking for values other than 0,0, which is likely to indicate a person with an actual computer and pointing device is at the other end. That still may not get what you want for touch screen devices though. You might also consider waiting until you detect a scrolling event if your secondary scripts don’t need to load right away.