JavascriptExecutor in Selenium
This article will present you with a complete idea about the JavaScriptExecutor and how we can use it if any script fails while using selenium.
We will learn below topics in this article
What is JavaScriptExecutor?
JavaScriptExecutor is an interface that provides a mechanism to execute Javascript through selenium driver.
It provides “executescript” & “executeAsyncScript” methods, to run JavaScript in the context of the currently selected frame or window.
We can use it directly by importing the package ‘org.openqa.selenium.JavascriptExecutor.’
Why use JavaScriptExecutor in Selenium?
Selenium Webdriver can perform multiple operations on web elements like sending data, clicking buttons, etc. so sometimes webdriver commands will not work as expected due to various reasons. In such cases , we can use JavaScriptExecutor
We use different web locator strategies like ID, Name, CSS selector, and XPath, etc for identification of webElements and If these locators do not work as expected, then we can use JavaScriptExecutor to perform the expected operation on the WebElement.
In a similar manner some time driver.click() doesn’t work and user is unable to click then we can click on the particular element with the help of JavascriptExecutor , below is the sample command for this
JavascriptExecutor js = ((JavascriptExecutor) driver);
js.executeScript("arguments[0].click();", element);What are the javaScriptExecutor Methods?
JavascriptExecutor consists of two methods
executeAsyncScript
This method execute an asynchronous piece of JavaScript in the context of the currently selected frame or window. Asynchronous script renders the web page quickly.
executeScript
This method 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.
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.
Syntax:
JavascriptExecutor js = (JavascriptExecutor) driver; js.executeScript(Script,Arguments);
- Script – The JavaScript to execute
- Arguments – It is the arguments to the script. It’s optional.
- Returns –could be anything from Boolean, Long, String, List, WebElement, or null.
How does JavascriptExecutor work in Selenium?
Lets understand how can we use JavascriptExecutor using below examples
First create a reference for the interface and assign it to the WebDriver instance by type casting it.
JavascriptExecutor js = (JavascriptExecutor) driver;
Now we can call the use below syntax based on the usage
To Click on a Button
js.executeScript("document.getElementById('enter element id').click();");
//or
js.executeScript("arguments[0].click();", okButton);
To Type Text in a Text Box
js.executeScript("document.getElementById(id').value='someValue';");
js.executeScript("document.getElementById('Email').value='SeleniumTesting.com';");
To generate Alert Pop window in Selenium Webdriver
js.executeScript("alert('Welcome To Selenium Testing');");
To refresh browser window using Javascript
js.executeScript("history.go(0)");
To get the domain name
String domainName= js.executeScript("return document.domain;").toString();
System.out.println(domainName);
To get the Title of our webpage
String titleText = js.executeScript("return document.title;").toString();
System.out.println(titleText);
To get the URL of a webpage
String url= js.executeScript("return document.URL;").toString();
System.out.println(url);
To get the Height and Width of a web page
js.executeScript(“return window.innerHeight;”).toString(); js.executeScript(“return window.innerWidth;”).toString();
To navigate to a different page using Javascript
js.executeScript("window.location = “URL”);
To perform Scroll on an application using Selenium
a) To scroll the page vertically for 500px
js.executeScript(“window.scrollBy(0,500)”);
b) To scroll the page vertically till the end
js.executeScript(“window.scrollBy(0,document.body.scrollHeight)”);