I seem to be writing a lot of code as of late that needs to check if a certain element is a child of another element. This is extremely useful in drag and drop operations (for determine where an element is being dropped) or if you want to make sure that a global event was trigger on a specific set of elements (I use this to check if a document.click occurred on a specific container.)
While jQuery makes this easy enough to do, I don't find the code very readable or reusable so I started using the following snippet:
What this does is checks to see if the current element is a child of the specified selector. For example:
This function definitely comes in handy when doing any sort of event delegation and I hope it eventually makes its way into the jQuery core in some form or another.