DOMSubtreeModified ... How to ensure it only fires once?

Question

When using DOMSubtreeModified I get multiple, sometimes 30+ events firing. Is it possible to ensure that my function is only called once regardless of DOMSubtreeModified is fired?

Answer 1

The Mutation Events are performance hogs which can't really be tamed well. Therefore, they have been deprecated over a year ago and should be used only when really needed.

You could use the new and shiny Mutation Observers from DOM Level 4 (follow the links there!). Where DOMSubtreeModified fired a thousand times, MutationObserver fires only once with all the modifications contained and accessible.

Works for (as of 2012/06):

• Chrome 18+ (prefixed, window.WebKitMutationObserver)
• Firefox 14+ (unprefixed)
• WebKit nightlies

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Other than that ... some hackish solution with removing the listener and scheduling to add it again in some time in future (a second or two) might be worth exploring.