Selenium | Use JavaScript to solve the difficult page operations

JavascriptExecutor

It is Javascript executor.

arguments[i] is a placeholder for JS script to pass arguments, and i starts from 0.

Scroll webpage

Several ways of scrolling pages:

JavascriptExecutor jse = (JavascriptExecutor)driver;

// Scroll to a element (tips: especially useful when elements are invisible or blocked)
jse.executeScript("arguments[0].scrollIntoView();", element);

// Scroll down
jse.executeScript("window.scrollBy(0, 500)", "");
jse.executeScript("scroll(0, 500);");

// Scroll to buttom
jse.executeScript("window.scrollTo(0, document.body.scrollHeight)");

// height of dynamic element
double ImageHeight = eachtile.getSize().getHeight();
double f = 1.04*ImageHeight;
((JavascriptExecutor)driver).executeScript("window.scrollBy(0,arguments[0]);", -f);

Get text inside elements

<div class="item-price">100 Yuan</div>

<div class="item-price">
  <span>200 Yuan</span>
  300 Yuan
</div>

div may or may not have span, anyway I don’t want the text inside span, that is, it is expected to get 100 Yuan and 300 Yuan.

WebElement element = driver.findElement(By.xpath("//div[contains(@class, 'item-price')]"));

JavascriptExecutor jse = (JavascriptExecutor)driver;
jse.executeScript("return arguments[0].lastChild.textContent;", element);

Click invisible item from a very long list

public void selectListByJS() {
    JavascriptExecutor js = (JavascriptExecutor) driver;
    String css;
    css = "document.querySelectorAll('.select-menu')[0].querySelector('.select-option:nth-child(24)').click();";
    js.executeScript(css);
}


// Another Solution:
// modify attribute to make it visible
// tip: I haven't check this solution out yet :)
String strJs = "document.getElementsByClassName('arguments[0]').style.height='auto'; document.getElementsByClassName('arguments[0]').style.visibility='visible';";

Click element

/**
 * tips: Suitable for Click () failure
 *
 * @param element
 */
public void clickByJS(WebElement element) {
	JavascriptExecutor jse = (JavascriptExecutor)driver;
	jse.executeScript("arguments[0].click()", element);
}

Reference

https://www.guru99.com/execute-javascript-selenium-webdriver.html