highlightWords

Highlight Words

Tento skript by neměl být instalován přímo. Jedná se o knihovnu, kterou by měly jiné skripty využívat pomocí meta příkazu // @require https://update.greasyfork.org/scripts/535935/1588732/highlightWords.js

K instalaci tototo skriptu si budete muset nainstalovat rozšíření jako Tampermonkey, Greasemonkey nebo Violentmonkey.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Violentmonkey.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Userscripts.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat manažer uživatelských skriptů.

(Už mám manažer uživatelských skriptů, nechte mě ho nainstalovat!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(Už mám manažer uživatelských stylů, nechte mě ho nainstalovat!)

function escapeRegex(string) {
  return string.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
}

function highlightWords(words, highlightClass = 'highlight') {
  if (!words || words.length === 0) return;

  // Create patterns for words and phrases
  const patterns = words.map(word => {
    const trimmed = word.trim();
    if (trimmed.includes(' ')) {
      // Handle phrases
      const parts = trimmed.split(/\s+/);
      const escapedParts = parts.map(escapeRegex);
      const pattern = escapedParts.map(part => `\\b${part}\\b`).join('\\s+');
      return { pattern, numWords: parts.length };
    } else {
      // Handle single words
      const escaped = escapeRegex(trimmed);
      const pattern = `\\b${escaped}\\b`;
      return { pattern, numWords: 1 };
    }
  });

  // Sort patterns by number of words descending to match longer phrases first
  patterns.sort((a, b) => b.numWords - a.numWords);

  // Create the regex pattern by joining all patterns with '|'
  const regexPattern = patterns.map(p => p.pattern).join('|');
  const regex = new RegExp(regexPattern, 'gi');

  // Select text nodes excluding script, style, and already highlighted elements
  const xpath = `//text()[not(ancestor::script) and not(ancestor::style) and not(ancestor::*[contains(concat(" ", normalize-space(@class), " "), " ${highlightClass} ")])]`;
  const textNodes = document.evaluate(xpath, document, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);

  for (let i = 0; i < textNodes.snapshotLength; i++) {
    const textNode = textNodes.snapshotItem(i);
    const text = textNode.nodeValue;
    const matches = [...text.matchAll(regex)];

    if (matches.length > 0) {
      const fragment = document.createDocumentFragment();
      let lastIndex = 0;

      for (const match of matches) {
        const offset = match.index;
        if (offset > lastIndex) {
          fragment.appendChild(document.createTextNode(text.slice(lastIndex, offset)));
        }
        const span = document.createElement('span');
        span.className = highlightClass;
        span.textContent = match[0];
        fragment.appendChild(span);
        lastIndex = offset + match[0].length;
      }

      if (lastIndex < text.length) {
        fragment.appendChild(document.createTextNode(text.slice(lastIndex)));
      }

      textNode.parentNode.replaceChild(fragment, textNode);
    }
  }
}