Selenium: Can I set any of the attribute value of a WebElement in Selenium?

You would have to use the JavascriptExecutor class:

WebDriver driver; // Assigned elsewhereJavascriptExecutor js = (JavascriptExecutor) driver;js.executeScript("document.getElementById('//id of element').setAttribute('attr', '10')");

If you're using the PageFactory pattern or already have a reference to your WebElement, then you probably want to set the attribute, using your existing reference to the WebElement. (Rather than doing a document.getElementById(...) in your javascript)

The following sample allows you to set the attribute, using your existing WebElement reference.

Code Snippet

import org.openqa.selenium.WebElement;import org.openqa.selenium.remote.RemoteWebDriver;import org.openqa.selenium.support.FindBy;public class QuickTest {    RemoteWebDriver driver;    @FindBy(id = "foo")    private WebElement username;    public void exampleUsage(RemoteWebDriver driver) {        setAttribute(username, "attr", "10");        setAttribute(username, "value", "bar");    }    public void setAttribute(WebElement element, String attName, String attValue) {        driver.executeScript("arguments[0].setAttribute(arguments[1], arguments[2]);",                 element, attName, attValue);    }}

Fancy C# extension method based on previous answers:

public static IWebElement SetAttribute(this IWebElement element, string name, string value){    var driver = ((IWrapsDriver)element).WrappedDriver;    var jsExecutor = (IJavaScriptExecutor)driver;    jsExecutor.ExecuteScript("arguments[0].setAttribute(arguments[1], arguments[2]);", element, name, value);    return element;}

Usage:

driver.FindElement(By.Id("some_option")).SetAttribute("selected", "selected");