Converting a Regex Expression that works in Chrome to work in Firefox

Question

I have this Regex Expression that works in chrome but doesn't not work in Firefox. SyntaxError: invalid regexp group

It has something to do with lookbehinds and Firefox does not support these. I need this to work in Firefox can some one help me convert this so it works in Firefox and filters out the tags as well?

        return new RegExp(`(?!<|>|/|&amp|_)(?<!</?[^>]*|&[^;]*)(${term})`, 'gi');
      };
      searchTermsInArray.forEach(term => {
        if (term.length) {
          const regexp = this.regexpFormula(term);
          newQuestion.qtiData.prompt = newQuestion.qtiData.prompt.replace(regexp, match => {
            return `<span class="highlight">${match}</span>`;
          });```

In chrome it filters out the html tags and returns the search term with a <span class="highlight">.

score 0 · Answer 1 · answered Jun 25 '19 at 18:55

0

You could try to solve things without using a negative lookbehind: do the opposite, match what you do not want as well. If it is there in your callback, then make sure to not highlight.

Note: I am not sure what the negative lookahead is accomplishing at the beginning, as you could easily make sure that the search term doesn't start with the listed values and that would yield the same result, so I am letting this part aside.

let regexp = new RegExp(`(&[^;]*|</?[^>]*)?(${term})`, 'gi');
haystack.replace(regexp, (match, ignore, term) => ignore ? match : `<span class="highlight">${term}</span>`);

answered Jun 25 '19 at 18:55

Bali Balo

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it using the negative lookaheads to ignore those characters and ignore html tag in general - yours works but doesnt ignore the html tags – Ethan M Jun 25 '19 at 20:23
@EthanM What do you mean by that? Using 'abc' has the term and `test` as the haystack I don't get any highlight. If you want to ignore when term itself is `` you can detect that beforehand and skip the full replace when that's the case. Note: you should also prepare term by protecting characters with special meaning in regexps (e.g. `)` -> `\)`) otherwise it will break – Bali Balo Jun 25 '19 at 20:38

Converting a Regex Expression that works in Chrome to work in Firefox

1 Answers1