Implicit vs Explicit vs Fluent Wait

ImplicitWait

ImplicitWait is an implementation to configure the WebDriver instance i.e. the driver to poll the HTML DOM for a certain amount of time (interms of NANOSECONDS, MICROSECONDS, MILLISECONDS, SECONDS, MINUTES, HOURS or DAYS) when trying to find an element or elements if they are not immediately available. The default setting is 0 which means the driver when finds an instruction to find an element or elements, the search starts and results are available on immediate basis.

In this case, after a fresh loading of a Webpage an element or elements may be / may not be found on an immediate search. So your Automation Framework may be facing any of these exceptions:

• NoSuchElementException
• TimeoutException
• ElementNotVisibleException
• ElementNotSelectableException

Hence you need to induce ImplicitWait. By introducing ImplicitWait the driver will poll the DOM Tree for the configured amount of time looking out for the element or elements. By that time the element or elements for which you had been looking for may be available in the DOM. As in your code you have already set ImplicitWait to a value of 10 seconds, the driver will poll the DOM for 10 seconds.

• Python:

  driver.implicitly_wait(10)
  

• Java:

  driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
  

Finally, once you set the ImplicitWait, the WebDriver instance i.e. the driver is able to carry this configuration till its lifetime. But if you need to change the coarse of time for the WebDriver instance i.e. the driver to wait then you can reconfigure it as follows:

• Python:

  driver.implicitly_wait(5)
  

• Java:

  driver.manage().timeouts().implicitlyWait(5, TimeUnit.SECONDS);
  

If at any point of time you want to nullify the ImplicitWait you can reconfigure it as follows:

• Python:

  driver.implicitly_wait(0)
  

• Java:

  driver.manage().timeouts().implicitlyWait(0, TimeUnit.SECONDS);
  

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Fluent Wait

Fluent Wait is the implementation of the Wait interface through which we can configure the timeout and polling interval on the fly. An instance of FluentWait can be defined to configure the maximum amount of time to wait for a condition as well as the frequency at which the condition must be checked. User can also configure the wait to ignore specific types of exceptions while waiting for an element, such as NoSuchElementException on the page.

• Usage:

     // Waiting 30 seconds for an element to be present on the page, checking
     // for its presence once every 5 seconds.
     Wait<WebDriver> wait = new FluentWait<WebDriver>(driver)
         .withTimeout(30, SECONDS)
         .pollingEvery(5, SECONDS)
         .ignoring(NoSuchElementException.class);
  
     WebElement foo = wait.until(new Function<WebDriver, WebElement>() {
       public WebElement apply(WebDriver driver) {
         return driver.findElement(By.id("foo"));
       }
     });
  

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ExplicitWait

ExplicitWait commonly known as WebDriverWait is a specialized implementation of FluentWait through which user can define, configure and implement for the WebDriver instance to wait for a certain condition to be met before proceeding for the next line of code. There are some methods that helps us to implement ExplicitWait that will wait only as long as required. WebDriverWait inconjunction with ExpectedConditions is one of the way ExplicitWait can be achieved.

An Example:

import org.openqa.selenium.WebElement;
import org.openqa.selenium.support.ui.ExpectedConditions;
import org.openqa.selenium.support.ui.WebDriverWait;
.
.
.
WebDriverWait wait = new WebDriverWait(driver, 10);
WebElement element = wait.until(ExpectedConditions.visibilityOfElementLocated(By.xpath("element_xpath")));
element.click();

Explanation:

This implementation of ExplicitWait waits up to 10 seconds before throwing a TimeoutException or if it finds the element then it will return within 0 to 10 seconds. WebDriverWait by default calls the ExpectedCondition every 500 milliseconds until it returns successfully. A successful return value for the ExpectedCondition function type is a Boolean value of true or a not-null object.

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Expected Conditions:

There are some frequently encountered conditions when automating Web Browsers for Testing Web/Mobile Applications. The Java, C# and Python bindings include those convenient methods so we don’t have to write-up an ExpectedCondition class ourselves or create our own utility package for them. Some of the Expected Conditions are:

• alertIsPresent()
• elementToBeClickable(locator)
• elementToBeSelected(WebElement)
• frameToBeAvailableAndSwitchToIt(locator)
• invisibilityOf(element)

You can find about the all the methods supported by Expected Conditions here.

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This particular query :

• When searching for a single element, the driver will poll the OM until the element has been found or the configured timeout expires before throwing a NoSuchElementException.
• When searching for multiple elements, the driver will poll the DOM until at least one element has been found or the configured timeout has expired.

So as per the first case, driver will wait for 3 seconds only.