This question already has an answer here:
I have some input HTML and I need to highlight some words in it.
I saw many advices how to do it and now I use preg_replace.
$output = preg_replace("/\w*?" . preg_quote($keyword) . "\w*/i",
"<span class=\"entity_hilight\">$0</span>", $input);
It works good at all, but if the input HTML does not contain a keyword in some of attributes of tags.
For example if I need to highlight keyword "Hawaii", this HTML code will be broken after applying the code above:
Hawaii is on of the best places for fun and recreation. Welcome to <a href="http://example.com/Hawaii">Hawaii hotels</a>
Because the code will replace Hawaii not only in the <a> tag, but in the href attribute too.
So how to avoid breaking HTML code with highlighting? Please note that I need to highlight words inside and outside HTML tags both, also it should work properly with nested tags. Tags as well as attributes can have any, even custom names, so I can't explicitly define any list of possible tag and attribute names. Also sometimes keyword can match not only with attribute value, but with attribute name or tag name (for example if I would need higlight keyword "strong" or "article" or "class").
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