Loading the Components

What is LoadableComponent? #

LoadableComponent is a base class that aims to ensure:

• Pages are loaded.
• The initial state of the page is asserted.
• The elements are intractable before we use them.

It helps in debugging the failure of a page to load and in reducing flakiness due to page load issues.

Without LoadableComponent #

Following is a sample LoginPage.java (Page Object) without LoadableComponent.

package com.example.webdriver;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;


public class LoginPage {

  private final WebDriver driver;

  public LoginPage(WebDriver driver) {
    this.driver = driver;
  }

  public void setName(String name) {
    WebElement field = driver.findElement(By.id(“name”));
    clearAndType(field, name);
  }

  public void setPassword(String pwd) {
    WebElement field = driver.findElement(By.name(“password”));
    clearAndType(field, pwd);
  }


  public HomePage submit() {
    driver.findElement(By.id("submit")).click();
    return new HomePage(driver);
  }

  private void clearAndType(WebElement field, String text) {
    field.clear();
    field.sendKeys(text);
  }

}

Creating an instance of the page object:

LoginPage page = new LoginPage(driver)

With LoadableComponent #

Now, to turn this code into a loadable component, LoginPage has to extend the LoadableComponent class and implement two methods load() and isLoaded().

public class LoginPage extends LoadableComponent<LoginPage> {

  // rest of class ignored for now

  @Override
  protected void load() {
    driver.get("https://www.facebook.com/”);
  }

  @Override
  protected void isLoaded() throws Error {
    String url = driver.getCurrentUrl();
    assertTrue(url.contains("facebook"), "current url " + url + " exepcted to contain 'facebook'");
  }

}

Creating an instance of the page object:

LoginPage page = new LoginPage(driver).get()

Please notice the calling get() method on the created page object instance. This will internally call the isLoaded() method, to ensure that the page is loaded properly by satisfying the condition in the isLoaded() method. When the URL is not correct, the control goes to load() function for the mitigation because the assertion failed. The load() function simply reloads the page. This will double-check that the page is indeed loaded completely.

One more implementation of LoadableComponent, called SlowLoadableComponent, is used in place of LoadableComponent when the page may load slowly. Here, we give a maximum timeout before the page could load completely.

public class LoginPage extends SlowLoadableComponent<LoginPage> {

  public LoginPage() {
    super(java.time.Clock.systemDefaultZone(), 60000);
  }

  // rest of class ignored for now

  @Override
  protected void load() {
    driver.get("https://www.facebook.com/”);
  }

  @Override
  protected void isLoaded() throws Error {
    String url = driver.getCurrentUrl();
    assertTrue(url.contains("facebook"), "current url " + url + " exepcted to contain 'facebook'");
  }

  @Override
  protected void isError() throws Error {
    super.isError();
  }

}

Behavior is just the same as LoadableComponent except that the isLoaded() method is checked until the given maximum timeout is reached while checking for isLoaded() and isError() at certain intervals.