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)
          Executes JavaScript in the context of the currently selected frame or window.
 

Method Detail

executeScript

java.lang.Object executeScript(java.lang.String script,
                               java.lang.Object... args)
Executes JavaScript in the context of the currently selected frame or window. The script fragment provided will be executed as the body of an anonymous function.

Within the script, use document to refer to the current document. Note that local variables will not be available once the script has finished executing, though global variables will persist.

If the script has a return value (i.e. if the script contains a return statement), then the following steps will be taken:

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 used as the script's result. This value will be handled as follows:

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.


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