dom util

dom manipulation util

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/499616/1635544/dom%20util.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!)

const HtmlSanitizer = {
  tempElement: document.createElement("div"),
  sanitize: function (/** @type {string} */ htmlString) {
    this.tempElement.innerText = htmlString;
    return this.tempElement.innerHTML;
  },
};

// Feature detection for Trusted Types
let trustedHTMLPolicy;
if (window.trustedTypes && window.trustedTypes.createPolicy) {
  trustedHTMLPolicy = window.trustedTypes.createPolicy('mmHtmlPolicy', {
    createHTML: (input) => input // Add sanitization logic here if necessary
  });
}

class HtmlString extends String {
  /**@type {HTMLElement|null} */
  element = null;

  /**@param {string} value */
  constructor(value) {
    super(value);
  }

  /**@returns {HTMLElement} */
  asElement() {
    if (this.element !== null) {
      return this.element;
    }

    const temp = document.createElement("div");
    
    // Use Trusted Types if available, otherwise fall back to direct assignment
    if (trustedHTMLPolicy) {
      temp.innerHTML = trustedHTMLPolicy.createHTML(this.valueOf());
    } else {
      temp.innerHTML = this.valueOf();
    }
    
    if (temp.childElementCount > 1) {
      throw new Error("html template does not accept more than 1 element");
    }

    this.element = /**@type {HTMLElement} */ (temp.firstElementChild);
    return /**@type {HTMLElement} */ (this.element);
  }
}

/**
 * @param {string} selector
 * @param {HTMLElement|Document} rootElement
 * @returns {HTMLElement|null}
 */
function $findElm(selector, rootElement = document) {
  return /**@type {HTMLElement|null} */ (rootElement.querySelector(selector));
}

/**
 * @param {string} selector
 * @param {HTMLElement|Document} rootElement
 * @returns {HTMLElement}
 */
function $findElmStrictly(selector, rootElement = document) {
  const element = /**@type {HTMLElement|null} */ (rootElement.querySelector(selector));
  if (element === null) {
    throw new Error(`Element with selector '${selector}' not found`);
  }

  return element;
}

/**
 * @param {string} selector
 * @returns {NodeListOf<HTMLElement>}
 */
function $findAll(selector) {
  return /**@type {NodeListOf<HTMLElement>} */ (document.querySelectorAll(selector));
}

/**@typedef {string|HtmlString|number|boolean} TInterpolatedValue */

/**
 * safe html interpolation
 * @param {TemplateStringsArray} literalValues
 * @param {TInterpolatedValue[]|TInterpolatedValue[][]} interpolatedValues
 * @returns {HtmlString}
 */
function html(literalValues, ...interpolatedValues) {
  let result = "";

  interpolatedValues.forEach((currentInterpolatedVal, idx) => {
    let literalVal = literalValues[idx];
    let interpolatedVal = "";
    if (Array.isArray(currentInterpolatedVal)) {
      interpolatedVal = currentInterpolatedVal.join("\n");
    } else if (typeof currentInterpolatedVal !== "boolean") {
      interpolatedVal = currentInterpolatedVal.toString();
    }

    const isSanitize = !literalVal.endsWith("$");
    if (isSanitize) {
      result += literalVal;
      result += HtmlSanitizer.sanitize(interpolatedVal);
    } else {
      literalVal = literalVal.slice(0, -1);

      result += literalVal;
      result += interpolatedVal;
    }
  });

  result += literalValues.slice(-1);
  return new HtmlString(result);
}

/**
 * wait for element to be added to the DOM
 * @param {string} selector
 * @param {number} timeout
 * @param {(element: HTMLElement) => void} callback
 * @returns {CallableFunction | null} callback to stop observing
 */
function waitForElement(selector, timeout, callback) {
  let matchingElement = /**@type {HTMLElement|null} */ (document.querySelector(selector));
  if (matchingElement) {
    callback(matchingElement);
    return null;
  }

  const observer = new MutationObserver((mutations) => {
    for (let mutation of mutations) {
      if (!mutation.addedNodes) continue;

      for (let node of mutation.addedNodes) {
        if (node.matches && node.matches(selector)) {
          callback(node);
          observer.disconnect();
          clearTimeout(timeoutId);
          return;
        }
        if (node.querySelector) {
          matchingElement = /**@type {HTMLElement|null} */ (node.querySelector(selector));
          if (matchingElement !== null) {
            callback(matchingElement);
            observer.disconnect();
            clearTimeout(timeoutId);
            return;
          }
        }
      }
    }
  });

  observer.observe(document.documentElement, {
    childList: true,
    subtree: true,
    attributes: false,
    characterData: false,
  });

  const timeoutId = setTimeout(() => {
    observer.disconnect();
    console.log(`Timeout reached: Element "${selector}" not found`);
  }, timeout);

  return () => {
    observer.disconnect();
  };
}

/**
 * Smoothly scrolls the page to the given element with an optional offset above it.
 *
 * @param {HTMLElement} el - The target element to scroll to.
 * @param {number} [offset=20] - The number of pixels to offset above the element.
 * @returns {void}
 */
function scrollToElementWithOffset(el, offset = 20) {
  const rect = el.getBoundingClientRect();
  const scrollTop = window.pageYOffset || document.documentElement.scrollTop;
  const targetY = rect.top + scrollTop - offset;

  window.scrollTo({
    top: targetY,
    behavior: 'smooth'
  });
}

/**
 * Appends a <style> tag with class 'mm-styles' and the given CSS rules to the document head.
 *
 * @param {string} cssText - The CSS rules to insert into the style tag.
 * @returns {HTMLStyleElement} The created style element.
 */
function addStyles(cssText) {
  const styleEl = document.createElement('style');
  styleEl.className = 'mm-styles';
  styleEl.textContent = cssText;
  document.head.appendChild(styleEl);
  return styleEl;
}