如何等到Selenium中存在元素？

Question

我正在尝试让Selenium等待页面加载后动态添加到DOM的元素。试过这个：

fluentWait.until(ExpectedConditions.presenceOfElement(By.id("elementId"));

如果它有帮助，这里是fluentWait：

FluentWait fluentWait = new FluentWait<>(webDriver) {
    .withTimeout(30, TimeUnit.SECONDS)
    .pollingEvery(200, TimeUnit.MILLISECONDS);
}

但它抛出一个NoSuchElementException - 看起来像presenceOfElement期望元素在那里所以这是有缺陷的。这必须是Selenium的面包和黄油，不想重新发明轮子...任何人都可以建议一个替代方案，理想情况下没有滚动我自己的Predicate？

Answer 1

当ignoring等待时，你需要调用WebDriver，但要忽略。

FluentWait<WebDriver> fluentWait = new FluentWait<>(driver)
        .withTimeout(30, TimeUnit.SECONDS)
        .pollingEvery(200, TimeUnit.MILLISECONDS)
        .ignoring(NoSuchElementException.class);

有关详细信息，请参阅FluentWait的文档。但要注意这个条件已经在ExpectedConditions中实现，所以你应该使用

WebElement element = (new WebDriverWait(driver, 10))
   .until(ExpectedConditions.elementToBeClickable(By.id("someid")));

*Update for newer versions of Selenium:

withTimeout(long, TimeUnit) has become withTimeout(Duration)
pollingEvery(long, TimeUnit) has become pollingEvery(Duration)

所以代码看起来像这样：

FluentWait<WebDriver> fluentWait = new FluentWait<>(driver)
        .withTimeout(Duration.ofSeconds(30)
        .pollingEvery(Duration.ofMillis(200)
        .ignoring(NoSuchElementException.class);

等待的基本教程可以找到here。

Answer 2

WebDriverWait wait = new WebDriverWait(driver,5)
wait.until(ExpectedConditions.visibilityOf(element));

你可以在加载整个页面代码执行和抛出错误之前使用它。时间是秒

Answer 3

我建议你使用Selenide库。它允许编写更简洁和可读的测试。它可以等待语法更短的元素的存在：

$("#elementId").shouldBe(visible);

以下是测试Google搜索的示例项目：https://github.com/selenide-examples/google

Answer 4

public WebElement fluientWaitforElement(WebElement element, int timoutSec, int pollingSec) {

    FluentWait<WebDriver> fWait = new FluentWait<WebDriver>(driver).withTimeout(timoutSec, TimeUnit.SECONDS)
        .pollingEvery(pollingSec, TimeUnit.SECONDS)
        .ignoring(NoSuchElementException.class, TimeoutException.class).ignoring(StaleElementReferenceException.class);

    for (int i = 0; i < 2; i++) {
        try {
            //fWait.until(ExpectedConditions.invisibilityOfElementLocated(By.xpath("//*[@id='reportmanager-wrapper']/div[1]/div[2]/ul/li/span[3]/i[@data-original--title='We are processing through trillions of data events, this insight may take more than 15 minutes to complete.']")));
        fWait.until(ExpectedConditions.visibilityOf(element));
        fWait.until(ExpectedConditions.elementToBeClickable(element));
        } catch (Exception e) {

        System.out.println("Element Not found trying again - " + element.toString().substring(70));
        e.printStackTrace();

        }
    }

    return element;

    }

Answer 5

FluentWait抛出NoSuchElementException是混乱的情况

org.openqa.selenium.NoSuchElementException;     

同

java.util.NoSuchElementException

在

.ignoring(NoSuchElementException.class)