How do you wait for jQuery Ajax calls to complete in Selenium 2

Question

I use Selenium 2 in C# to automate testing of our web sites. When building non-Ajax functionality, using webDriver.FindElement(By.Id("element-id")) to find elements on a page works fine, but when doing jQuery Ajax calls this doesn't work because it tries to find the element before the ajax request has finished.

How do I tell Selenium to wait until the jQuery Ajax has completed?

Answer 1

The class you are looking for is the WebDriverWait class that you can find here (C#): http://code.google.com/p/selenium/source/browse/trunk/dotnet/src/WebDriver.Support/UI/WebDriverWait.cs

I created an extension method to make it easier to use that looks something like this:

public static class BrowserExtensions
{
    public static T WaitUntil<T>(this IWebDriver browser, Func<IWebDriver, T> condition, int timeout = 5)
    {
        var wait = new WebDriverWait(browser, new TimeSpan(0, 0, timeout));
        return wait.Until(condition);
    }
}

You can then use it like this:

var element = webDriver.WaitUntil(x => x.FindElement(By.Id("element-id")));

Note that this does not guarantee that the element is visible when you get it back!

Also I should probably mention that I have experienced problems using the WebDriverWait class and I think it could use some work to make it more stable.

Answer 2

A possibly more generic solution to this problem is to wait for the jquery to complete. You can do this with a function like this:

public void WaitForAjax()
{
    while (true) // Handle timeout somewhere
    {
        var ajaxIsComplete = (bool)(driver as IJavaScriptExecutor).ExecuteScript("return jQuery.active == 0");
        if (ajaxIsComplete)
            break;
        Thread.Sleep(100);
    }
}

Answer 3

Fairly ceertain that there is a Wait class that you can access. From the docs:

public abstract class Wait extends java.lang.Object

A utility class, designed to help the user automatically wait until a condition turns true. Use it like this:

new Wait("Couldn't find close button!") { boolean until() { return selenium.isElementPresent("button_Close"); } };

Answer 4

I actually wrote my own wait_for_element method on the page objects for my selenium tests. You will need:

• Success check function

  return element.isVisible()

• A function to define what you are getting

  webDriver.FindElement(By.Id("element-id"))

• Length of time prepared to wait and how often to check

This was all written before the Wait class was added to selenium 2/webdriver. I have not yet had a chance to use the Wait class, does anyone know if it is any good? I noticed one answer said selenium2 might need to work on it a bit

Answer 5

A similar question was asked on Stack Overflow with an excellent answer if you can consider using he PageObject model.

Using PageFactory to init elements on AJAX pages