org.openqa.selenium
Interface JavascriptExecutor

public interface JavascriptExecutor

Indicates that a driver can execute Javascript, providing access to the mechanism to do so.

Method Summary

java.lang.Object	executeAsyncScript(java.lang.String script, java.lang.Object... args) Execute an asynchronous piece of JavaScript in the context of the currently selected frame or window.
java.lang.Object	executeScript(java.lang.String script, java.lang.Object... args) Execute javascript in the context of the currently selected frame or window.
boolean	isJavascriptEnabled() It's not enough to simply support javascript, it also needs to be enabled too.

Method Detail

executeScript

java.lang.Object executeScript(java.lang.String script,
                               java.lang.Object... args)

Execute javascript in the context of the currently selected frame or window. This means that "document" will refer to the current document. If the script has a return value, then the following steps will be taken:

• For an HTML element, this method returns a WebElement
• For a decimal, a Double is returned
• For a non-decimal number, a Long is returned
• For a boolean, a Boolean is returned
• For all other cases, a String is returned.
• For an array, return a List<Object> with each object following the rules above. We support nested lists.
• Unless the value is null or there is no return value, in which null is returned

Arguments must be a number, a boolean, a String, WebElement, or a List of any combination of the above. An exception will be thrown if the arguments do not meet these criteria. The arguments will be made available to the javascript via the "arguments" magic variable, as if the function were called via "Function.apply"

Parameters:

script - The javascript to execute

args - The arguments to the script. May be empty

Returns:

One of Boolean, Long, String, List or WebElement. Or null.

executeAsyncScript

java.lang.Object executeAsyncScript(java.lang.String script,
                                    java.lang.Object... args)

Execute an asynchronous piece of JavaScript in the context of the currently selected frame or window. Unlike executing synchronous JavaScript, scripts executed with this method must explicitly signal they are finished by invoking the provided callback. This callback is always injected into the executed function as the last argument.

The first argument passed to the callback function will be uesd as the script's result. This value will be handled as follows:

• For an HTML element, this method returns a WebElement
• For a number, a Long is returned
• For a boolean, a Boolean is returned
• For all other cases, a String is returned.
• For an array, return a List<Object> with each object following the rules above. We support nested lists.
• Unless the value is null or there is no return value, in which null is returned

Example #1: Performing a sleep in the browser under test.

   long start = System.currentTimeMillis();
   ((JavascriptExecutor) driver).executeAsyncScript(
       "window.setTimeout(arguments[arguments.length - 1], 500);");
   System.out.println(
       "Elapsed time: " + System.currentTimeMillis() - start);
 

Example #2: Synchronizing a test with an AJAX application:

   WebElement composeButton = driver.findElement(By.id("compose-button"));
   composeButton.click();
   ((JavascriptExecutor) driver).executeAsyncScript(
       "var callback = arguments[arguments.length - 1];" +
       "mailClient.getComposeWindowWidget().onload(callback);");
   driver.switchTo().frame("composeWidget");
   driver.findElement(By.id("to")).sendKeys("[email protected]");
 

Example #3: Injecting a XMLHttpRequest and waiting for the result:

   Object response = ((JavascriptExecutor) driver).executeAsyncScript(
       "var callback = arguments[arguments.length - 1];" +
       "var xhr = new XMLHttpRequest();" +
       "xhr.open('GET', '/resource/data.json', true);" +
       "xhr.onreadystatechange = function() {" +
       "  if (xhr.readyState == 4) {" +
       "    callback(xhr.responseText);" +
       "  }" +
       "}" +
       "xhr.send();");
   JSONObject json = new JSONObject((String) response);
   assertEquals("cheese", json.getString("food"));
 

Parameters:

script - The javascript to execute.

args - The arguments to the script. May be empty.

Returns:

One of Boolean, Long, String, List, WebElement, or null.

isJavascriptEnabled

boolean isJavascriptEnabled()

It's not enough to simply support javascript, it also needs to be enabled too.