Javascript split by spaces, but not within html-tags

My first goal is to split a string by spaces, but not the ones within html-tags.

I've tried to rewrite the following, unsuccessfully: Javascript split by spaces but not those in quotes

What would the regex look like in: arr = fullHtmlString.split(?); ?

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My main goal is to shift an IMG-tag by one space at a time. After that I'll iterate over the array, search for the img-tag, remove it, and add it the next item, and finally join the array.

The code I use at the moment is quite comprehensive and use jQuery extensively to achive the goal.