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Is MutationRecord.oldValue something I should use?

I use the latest stable version of Google Chrome (19.0.1084.56 m) on Windows 7 and am experimenting with Mutation observers for the first time. (The project is a script user for a third-party site on whose server I do not have access.)

It so happened that MutationRecord has an oldValue field:

record . oldValue

The return value depends on type . For attributes , this is the value of the changed attribute before the change. For " characterData ", the data of the changed node is before the change. For " childList " it is null.

So, I'm tracking changes to characterData , but when I get a MutationRecord , the oldValue field oldValue always null.

Should it work, is there a chance that something is wrong with me, or is this function too short to wait for more work?

Somewhere I can find Google documentation, bug report, feature request, etc. that can declare whether this is implemented or when it can be?

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1 answer

Set up your observer with:

 observer.observe(container, { attributeOldValue : true });

Full API documentation: https://developer.mozilla.org/pt-BR/docs/Web/API/MutationObserver

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Source: https://habr.com/ru/post/919481/

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