只要我使用PageObject模式,我就想知道应该在哪里等待动态页面上的元素。假设我们有测试方法和pageObject类。我应该做类似的事情吗(在测试方法中):
也许还有其他好的做法来等待该要素?也许我们应该等待PageObject.class中的isElementDisplayed方法中的元素?
您应该等待页面对象类中的元素,而不是测试类中的元素,因为您的元素应该在页面对象类中定义,测试类应该不了解任何元素,选择器或类似元素。测试(恕我直言)应该只包含描述测试流程的方法调用链,与网站和基础DOM的所有交互都应在Page Object类中进行。
因此,等待某个元素出现的过于冗长的方法可能类似于:
private final By yourElement = By.id("id"); @Override public void isLoaded() throws Error { new FluentWait<WebDriver>(driver) .withTimeout(60, TimeUnit.SECONDS) .pollingEvery(1, TimeUnit.SECONDS) .ignoring(NoSuchElementException.class) .ignoring(StaleElementReferenceException.class) .until(new Function<WebDriver, Boolean>() { @NotNull @Override public Boolean apply(WebDriver webDriver) { WebElement element = driver.findElement(yourElement); return element != null && element.isDisplayed(); } }); }
用简单的话来说,该函数将轮询DOM 60秒(每1秒)以查看元素是否存在于DOM中并且可见(意味着高度和witdh大于1px)。如果该元素存在(并显示),则该函数将返回找到的元素并停止轮询(尽管isLoaded()在这种情况下方法不会返回该元素)。
isLoaded()
如果找不到元素NoSuchElementException,可以忽略findElement方法可能抛出的错误,并且StaleElementException,它指示对元素的引用现在已“陈旧”-该元素不再出现在页面的DOM上。这通常意味着,某些内容(最常见的是JS)已修改DOM,并且引用不再有效,因此WebDriver需要再次查找它。
NoSuchElementException
findElement
StaleElementException
WebDriver
当然,较短的代码也可以解决问题,例如:
new WebDriverWait(driver, 60) .until(ExpectedConditions.visibilityOf(someWebElement));
该文档实际上对此非常好。
编辑:评论的答案:
好,懂了。但是,如果在单击某个按钮等之后存在元素,该怎么办?
假设您有一个方案,其中有一个按钮,单击该按钮后,将出现一个文本框,您想与之交互。
public class PageObject extends LoadableComponent<PageObject>{ public PageObject() throws Exception { driver = getWebDriver(); PageFactory.initElements(driver, this); isLoaded(); } private WebDriver driver = null; @FindBy(id = "yourButton") private WebElement button; @FindBy(id = "textBoxThatAppears") private WebElement txtBox; @Override public void isLoaded() throws Error { // Initial loading, called when creating the page object to make sure that the page is loaded to a state where it is ready to interact with us, in our case it means that button is present in DOM and visible. waitForVisibility(button); } private void waitForVisibility(WebElement element) throws Error{ new WebDriverWait(driver, 60) .until(ExpectedConditions.visibilityOf(element)); } public void clickButton(){ button.click(); } public void interactWithTextbox(String text){ // Wait for txtBox to be visible, then send text waitForVisibility(txtBox); txtBox.sendKeys(text); // EDIT 27.04.14: // Actually you should not do the assertion here or anywhere in // the pageObject, because when reusing the method in some other test, you might // not want to assert, you might wonder that why wouldn't you assert some // specific condition every time, but I would throw that question right back // to you and ask: What is the point of checking the exact same thing over and // over again. There are 2 things, firstly the assertion takes resources (and // that can become important when test suite grows, secondly your tests can // simply start failing at the same point when one little condition is not as // it should be. Also, having the asserts in the test, makes the test more // readable and understandable for others. // end edit 27.04.14 // Next line is no longer recommended by this answer. // assert that something happened that you expected. } }
现在您的测试课:
public void TestClass { @Test public void testClickButtonAndInteractWithTextbox(){ // Initiate the page object Pageobject po = new PageObject(); po.clickButtonAndWaitForTextbox(); po.interactWithTextbox("blabla"); // edit 27.04.14 assertSomethingGoodHappened(); } }