The scrollClient function is an asynchronous function that scrolls a webpage to a specific position based on a given CSS selector, or to the top or bottom of the page if no selector is provided. It uses various functions such as selectDom and evaluateDom to dynamically import and evaluate code on the client-side to achieve the desired scroll position.

Run example

npm run import -- "Scroll a specific element"

Scroll a specific element

const {selectDom, evaluateDom} = importer.import("select tree")
const {walkTree} = importer.import("walk tree")

async function scrollClient(driver, selector, up = false) {
  // scroll to bottom of messages
  return await driver
    .executeScript((evaluateDomString, walkTreeString, selectDomString, selector, up = false) => {
      if (selector === '' || selector === false) {
        window.scroll(window.scrollX, window.scrollY + (up ? -100000 : 100000));
        return;
      }
      if(!window.evaluateDom)
        window.evaluateDom = eval('(' + evaluateDomString + ')')
      if(!window.walkTree)
        window.walkTree = eval('(' + walkTreeString + ')')
      if(!window.selectDom)
        window.selectDom = eval('(' + selectDomString + ')')
      var people = selectDom(selector, document)
      people.scrollTop = people.scrollTop + (up ? -100000 : 100000);
    }, evaluateDom, walkTree, selectDom, selector, up)
}

module.exports = scrollClient

const { selectDom, evaluateDom } = require('select-tree');
const { walkTree } = require('walk-tree');

/**
 * Scrolls the client to the top or bottom of the element specified by the selector.
 * 
 * @param {object} driver The driver instance
 * @param {string} selector The CSS selector of the element to scroll to
 * @param {boolean} up Whether to scroll to the top (default false)
 * @returns {Promise<void>} A promise that resolves when the scrolling is complete
 */
async function scrollClient(driver, selector, up = false) {
  // scroll to bottom of messages
  if (!selector) {
    // If no selector is provided, scroll to the bottom of the document
    await driver.executeScript('window.scroll(window.scrollX, window.scrollY + (arguments[3]? -100000 : 100000))', up);
    return;
  }

  // Evaluate the given functions and store them in the global object
  await driver.executeScript((evaluateDomString, walkTreeString, selectDomString, selector, up) => {
    if (!window.evaluateDom) {
      // Use Function constructor to safely evaluate the function string
      window.evaluateDom = new Function('window', `return ${evaluateDomString};`)({ window });
    }
    if (!window.walkTree) {
      window.walkTree = new Function('window', `return ${walkTreeString};`)({ window });
    }
    if (!window.selectDom) {
      window.selectDom = new Function('window', `return ${selectDomString};`)({ window });
    }

    // Select the element and scroll to the specified position
    const people = window.selectDom(selector, document);
    if (people) {
      people.scrollTop = people.scrollTop + (up? -100000 : 100000);
    } else {
      console.warn(`Element not found: ${selector}`);
    }
  }, evaluateDom.toString(), walkTree.toString(), selectDom.toString(), selector, up);
}

module.exports = scrollClient;

scrollClient Function Breakdown

Overview

The scrollClient function is an asynchronous function that scrolls a webpage to a specific position based on a given selector.

Parameters

• driver: An object likely representing a browser driver (e.g. Selenium).
• selector: A string representing the CSS selector for the element to scroll to.
• up: A boolean indicating whether to scroll up or down (default: false).

Functionality

1. If the selector is empty or false, the function scrolls the window to the top or bottom (depending on the up parameter) by 100,000 pixels.
2. If the evaluateDom, walkTree, or selectDom functions are not defined on the window object, they are dynamically imported and evaluated on the client-side using eval.
3. The selectDom function is called with the selector and document as arguments, and the resulting element is assigned to the people variable.
4. The scrollTop property of the people element is adjusted by 100,000 pixels (or -100,000 if up is true) to achieve the desired scroll position.

Export

The scrollClient function is exported as a module.