Selenium. Methods for waiting for load and reload.

selenium-waiters.java

import org.openqa.selenium.JavascriptExecutor;
import org.openqa.selenium.TimeoutException;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.support.PageFactory;
import org.openqa.selenium.support.pagefactory.FieldDecorator;
import org.openqa.selenium.support.ui.ExpectedCondition;
import org.openqa.selenium.support.ui.WebDriverWait;

import xxx.CustomFieldDecorator;
import xxx.CustomElementLocatorFactory;

import java.rmi.UnexpectedException;
import java.util.UUID;

public abstract class AbstractDocument {

	protected final WebDriver driver;
	protected final FieldDecorator decorator;
	private String loadMarkerId;
	
	public AbstractDocument(WebDriver driver, String prefix) {
		this.driver = driver;
		this.decorator = new CustomFieldDecorator(
				new CustomElementLocatorFactory(driver, prefix));
	}

	public void waitForLoad() throws InterruptedException { this.waitForLoad(null); }
	// will wait for page load and javascript code execution
	public void waitForLoad(Integer waitAfterLoad) throws InterruptedException {
	    new WebDriverWait(driver, 10).until((ExpectedCondition<Boolean>) wd ->
	            ((JavascriptExecutor) wd).executeScript("return document.readyState").equals("complete"));
	    this.createLoadMarker();	    
	    
	    // allow for the javascripts to execute so we can right away findElement after this void
		if (waitAfterLoad != null)
			Thread.sleep(waitAfterLoad);
	}
	

	private void waitInteractive() throws InterruptedException {
		// waits for the page to be at least 'interactive' - body DOM is present but not all element necessarily
	    new WebDriverWait(driver, 10).until((ExpectedCondition<Boolean>) wd ->
	            ((JavascriptExecutor) wd).executeScript("return document.readyState")
	            .toString().matches("interactive|complete"));
	}

	/**
	* Waits for the page to unload.
	* @throws UnexpectedException 
	*/
	public void waitForUnload() throws InterruptedException, UnexpectedException { this.waitForUnload(null); }
	/**
	* Waits for the page to unload.
	*
	* @param waitAfterUnload Milliseconds to wait after unload.
	* @throws UnexpectedException 
	*/
	public void waitForUnload(Integer waitAfterUnload) throws InterruptedException, UnexpectedException {
		if (this.loadMarkerId == null) 
			throw new UnexpectedException("Expected loader marker not initialized. Please use page.init() or page.waitForLoad() first.");
		try {
			new WebDriverWait(driver, 10).until((ExpectedCondition<Boolean>) wd -> !isMarkerLoaded(wd));
			this.loadMarkerId = null;
		} catch (TimeoutException e) {
			throw new TimeoutException("Timed out waiting for page to unload.", e);
		}
		if (waitAfterUnload != null)
			Thread.sleep(waitAfterUnload);
	}

	/**
	   * Waits for the window to reload, useful for switching pages or submitting forms.
	   * Underlying behavior is invoking waitForUnload and waitForLoad.
	 * @throws UnexpectedException 
	   *
	   */
	public void waitForReload() throws InterruptedException, UnexpectedException { this.waitForReload(null); }
	/**
	   * Waits for the window to reload, useful for switching pages or submitting forms.
	   * Underlying behavior is invoking waitForUnload and waitForLoad. 
	   *
	   * @param waitAfterReload Milliseconds. After the preceeding calls, Thread.sleep(waitAfterReload) will be invoked.
	 * @throws UnexpectedException 
	   */
	public void waitForReload(Integer waitAfterReload) throws InterruptedException, UnexpectedException {
		this.waitForUnload();
		this.waitForLoad();
	    Thread.sleep(waitAfterReload != null ? waitAfterReload : 0);
	}
	
	public enum CreateMarker {
		YES, NO
	}
	
	public void init() throws InterruptedException { init(CreateMarker.YES); }
	public void init(CreateMarker marker) throws InterruptedException {
		PageFactory.initElements(this.decorator, this);
		if (marker == CreateMarker.YES) {
			this.createLoadMarker();
		}
	}
	
	private void createLoadMarker() throws InterruptedException {
		this.waitInteractive();
		// inserts a marker variable
		if (isMarkerLoaded(driver)) return;
		this.loadMarkerId = ("seleniumloader" + UUID.randomUUID().toString()).replaceAll("-", "");
		((JavascriptExecutor) driver).executeScript("window." + this.loadMarkerId + " = true;");
	}
	
	private Boolean isMarkerLoaded(WebDriver driver) {
		if (this.loadMarkerId == null) 
			return false;
		return !(null == ((JavascriptExecutor) driver).executeScript("return window." + this.loadMarkerId));
	}
}