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//
// http://www.apache.org/licenses/LICENSE-2.0
//
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package org.openqa.selenium;
import java.util.Collections;
import java.util.Set;
import java.util.stream.Collectors;
import org.openqa.selenium.internal.Require;
/**
* Indicates that a driver can execute JavaScript, providing access to the mechanism to do so.
*
* Because of cross domain policies browsers enforce your script execution may fail unexpectedly
* and without adequate error messaging. This is particularly pertinent when creating your own XHR
* request or when trying to access another frame. Most times when troubleshooting failure it's best
* to view the browser's console after executing the WebDriver request.
*/
public interface JavascriptExecutor {
/**
* 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:
*
*
* - 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.
*
- For a map, return a Map<String, Object> with values following the rules above.
*
- 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"
*
* @param script The JavaScript to execute
* @param args The arguments to the script. May be empty
* @return One of Boolean, Long, Double, String, List, Map or WebElement. Or null.
*/
Object executeScript(String script, Object... args);
/**
* Execute an asynchronous piece of JavaScript in the context of the currently selected frame or
* window. Unlike executing {@link #executeScript(String, Object...) 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:
*
*
* - 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.
*
- For a map, return a Map<String, Object> with values following the rules above.
*
- Unless the value is null or there is no return value, in which null is returned
*
*
* The default timeout for a script to be executed is 0ms. In most cases, including the
* examples below, one must set the script timeout {@link
* WebDriver.Timeouts#scriptTimeout(java.time.Duration)} beforehand to a value sufficiently large
* enough.
*
*
Example #1: Performing a sleep in the browser under test.
*
*
{@code
* 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:
*
*
{@code
* 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:
*
*
{@code
* 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 JsonParser().parse((String) response);
* assertEquals("cheese", json.get("food").getAsString());
* }
*
* Script 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" variable.
*
* @param script The JavaScript to execute.
* @param args The arguments to the script. May be empty.
* @return One of Boolean, Long, String, List, Map, WebElement, or null.
* @see WebDriver.Timeouts#scriptTimeout(java.time.Duration)
*/
Object executeAsyncScript(String script, Object... args);
/**
* Commonly used scripts may be "pinned" to the WebDriver session, allowing them to be called
* efficiently by their handle rather than sending the entire script across the wire for every
* call.
*
*
The default implementation of this adheres to the API's expectations but is inefficient.
*
* @see #executeScript(ScriptKey, Object...)
* @param script The Javascript to execute.
* @return A handle which may later be used in {@link #executeScript(ScriptKey, Object...)}
* @throws JavascriptException If the script cannot be pinned for some reason.
*/
default ScriptKey pin(String script) {
Require.nonNull("Script to pin", script);
return UnpinnedScriptKey.pin(this, script);
}
/**
* Deletes the reference to a script that has previously been pinned. Subsequent calls to {@link
* #executeScript(ScriptKey, Object...)} will fail for the given {@code key}.
*/
default void unpin(ScriptKey key) {
Require.nonNull("Key to unpin", key);
Require.stateCondition(
key instanceof UnpinnedScriptKey, "Script key should have been generated by this driver");
UnpinnedScriptKey.unpin(this, (UnpinnedScriptKey) key);
}
/**
* @return The {@link ScriptKey}s of all currently pinned scripts.
*/
default Set getPinnedScripts() {
return Collections.unmodifiableSet(
UnpinnedScriptKey.getPinnedScripts(this).stream()
.map(key -> (ScriptKey) key)
.collect(Collectors.toSet()));
}
/**
* Calls a script by the {@link ScriptKey} returned by {@link #pin(String)}. This can be thought
* of as inlining the pinned script and simply calling {@link #executeScript(String, Object...)}.
*
* @see #executeScript(String, Object...)
*/
default Object executeScript(ScriptKey key, Object... args) {
Require.stateCondition(
key instanceof UnpinnedScriptKey, "Script key should have been generated by this driver");
if (!getPinnedScripts().contains(key)) {
throw new JavascriptException("Script is unpinned");
}
return executeScript(((UnpinnedScriptKey) key).getScript(), args);
}
}