Implementation question : Why would changesToReport return false?

Skip to first unread message

Sunil Agrawal

Sep 15, 2013, 11:41:00 PM9/15/13
I am using the library and has been very useful.

However, while debugging one of the issues, I started looking into mutation summary library came around a situation which I don't understand. The Mutation observer (from the browser) is giving about 30 odd mutations and after processing the mutations, the mutation library checks if there are any changes to report, and it's returning false.

My naive question is, under what situations will the incoming mutations not result into summaries being generated?

Thanks in advance,

Rafael Weinstein

Sep 16, 2013, 1:51:36 PM9/16/13
MutationSummary will not report changes even if there are underlying DOM mutations if the effect of the mutations is to negate each other. MutationSummary ALWAYS reports changes relative to the last time it reported. If in that time, some changes were made, but then effectively put back the way they were, it won't report anything -- because from your summary's point of view, nothing has changed.

You received this message because you are subscribed to the Google Groups "mutation-summary-discuss" group.
To unsubscribe from this group and stop receiving emails from it, send an email to
To post to this group, send email to
Visit this group at
For more options, visit

Reply all
Reply to author
0 new messages