ST - Selenium – 3 – Understanding WebDriver

 

 

Selenium – 3 – Understanding WebDriver

 

Selenium WebDriver is a tool used for automating web browsers. It provides a way to simulate user interactions with a website, such as clicking buttons, filling out forms, and navigating through pages. WebDriver is one of the components of the Selenium suite, which also includes the Selenium IDE and Selenium Grid.

WebDriver works by using a browser-specific driver to interact with the web browser. The driver acts as a bridge between the WebDriver and the browser, allowing the WebDriver to control the browser and execute actions on the web page.

When you create an instance of the WebDriver, you specify which browser you want to use (e.g., Chrome, Firefox, etc.), and the appropriate driver is loaded. Once the driver is loaded, you can interact with the browser using the methods provided by the WebDriver API.

WebDriver provides a wide range of methods for interacting with web pages, including finding elements on the page (by ID, class name, tag name, etc.), clicking on elements, filling out forms, and navigating between pages. You can also perform more advanced actions, such as executing JavaScript on the page or taking screenshots of the browser window.

In summary, WebDriver works by using a browser-specific driver to interact with a web browser, allowing you to automate user interactions with web pages.

let me give you a real-life example of how WebDriver works:

Imagine you are a software developer working on an e-commerce website. Your job is to test the website's functionality and ensure that it is working as expected.

One of the features you need to test is the checkout process. You need to verify that users can successfully complete a purchase and receive a confirmation message.

Using WebDriver, you can automate this process by creating a script that simulates a user's actions on the website. Here's how it works:

·         First, you create an instance of the WebDriver and specify the browser you want to use (let's say, Google Chrome).

·         Next, you navigate to the website's checkout page using the WebDriver's get method.

·         You then fill out the checkout form with test data using the send keys method to enter values into the form fields.

·         Once the form is filled out, you simulate clicking the "Place Order" button using the click method.

·         Finally, you verify that the website displays a confirmation message indicating that the order was successfully placed.

This entire process can be automated using WebDriver, allowing you to test the website’s checkout process quickly and easily without having to manually go through the process yourself.

WebDriver enables you to automate user interactions with a website, allowing you to test its functionality and ensure that it is working as expected.

1.       Why should we have a web driver , when we have individual drivers for each browser ?

While it's true that each browser has its own driver that can be used to automate interactions with that browser, there are several reasons why it's beneficial to use WebDriver instead:

1.       Cross-browser compatibility: One of the main benefits of using WebDriver is that it provides a unified API for interacting with multiple browsers. This means that you can write your test scripts once and run them on different browsers without having to make changes to the code. This saves time and effort and ensures that your tests are consistent across different browsers.

2.       Simplified setup: When using WebDriver, you only need to install a single driver for each browser, rather than having to install a different driver for each version of the browser. This makes it easier to set up and maintain your test environment.

3.       Improved performance: WebDriver is designed to work efficiently with each browser, providing faster and more reliable interactions with web pages compared to using individual browser drivers.

4.       Flexibility: WebDriver provides a rich set of APIs for interacting with web pages, including the ability to execute JavaScript, take screenshots, and perform other advanced actions. This gives you greater flexibility in how you automate interactions with a web page.

 While it's possible to use individual browser drivers to automate interactions with a single browser, using WebDriver provides a more flexible, efficient, and consistent approach to automating interactions with multiple browsers.

1.       Is webdriver an interface ?

Yes, WebDriver is an interface in the Selenium API. An interface is a collection of abstract methods that define a set of actions that can be performed by an object implementing that interface.

In the case of WebDriver, the interface defines a set of methods for controlling a web browser, such as navigating to a URL, finding elements on a web page, clicking buttons, filling out forms, and taking screenshots. The methods defined in the WebDriver interface are implemented by specific browser drivers, such as the ChromeDriver, FirefoxDriver, and EdgeDriver.

By defining a standard interface for controlling web browsers, WebDriver provides a unified approach to web automation that is independent of any specific browser or driver implementation. This allows test scripts written against the WebDriver interface to be run against different browsers, simply by changing the driver implementation.

let me give you an example of how WebDriver is used as an interface:

Suppose you are writing a Java program to automate interactions with a web page using Selenium WebDriver. Here's how you might create an instance of the WebDriver interface to control a web browser:

import org.openqa.selenium.WebDriver;

import org.openqa.selenium.chrome.ChromeDriver;

public class MyAutomationProgram {

    public static void main(String[] args) {

        // Create an instance of the ChromeDriver class

        WebDriver driver = new ChromeDriver();

        // Use the WebDriver to navigate to a web page

        driver.get("https://www.example.com");

        // Quit the browser

        driver.quit();

    }

}

In this example, we first import the WebDriver interface from the Selenium API, as well as the ChromeDriver class that implements the interface for controlling the Chrome browser.

Next, we create an instance of the ChromeDriver class and assign it to a variable of type WebDriver. This allows us to use the interface methods to control the browser, such as navigating to a web page using the get method.

By using the WebDriver interface, we can write test scripts that can be used to automate interactions with different browsers, simply by changing the driver implementation used to create the WebDriver instance. This provides a flexible and unified approach to web automation that is independent of any specific browser or driver implementation.

2.       What is chrome driver ?

ChromeDriver is a standalone executable that enables Selenium WebDriver to control the Chrome web browser. It is one of the browser drivers supported by Selenium, which also includes drivers for other popular browsers like Firefox, Edge, and Safari.

When you use Selenium WebDriver to automate interactions with a web page in Chrome, you need to have ChromeDriver installed on your system and in your system's PATH. You can download ChromeDriver from the official ChromeDriver website (https://sites.google.com/a/chromium.org/chromedriver/downloads), which provides pre-built executables for different operating systems.

Once you have downloaded ChromeDriver and added it to your system's PATH, you can use it in your Selenium test scripts to control Chrome. For example, here's how you might use ChromeDriver in a Java program to navigate to a web page and get the page title:

import org.openqa.selenium.WebDriver;

import org.openqa.selenium.chrome.ChromeDriver;

public class MyAutomationProgram {

    public static void main(String[] args) {

        // Set the path to the ChromeDriver executable

        System.setProperty("webdriver.chrome.driver", "/path/to/chromedriver");

        // Create an instance of the ChromeDriver class

        WebDriver driver = new ChromeDriver();

        // Use the WebDriver to navigate to a web page

        driver.get("https://www.example.com");

        // Get the page title and print it to the console

        String pageTitle = driver.getTitle();

        System.out.println("Page title is: " + pageTitle);

        // Quit the browser

        driver.quit();

    }

}

In this example, we first set the path to the ChromeDriver executable using the System.setProperty method. This tells Selenium where to find the ChromeDriver executable on our system.

Next, we create an instance of the ChromeDriver class and assign it to a variable of type WebDriver. We can then use the WebDriver methods to control Chrome, such as navigating to a web page using the get method and getting the page title using the getTitle method.

By using ChromeDriver, we can automate interactions with the Chrome web browser and integrate it into our Selenium test suite.

3.       What does Chrome driver have in it ?

ChromeDriver is a standalone executable program that provides the bridge between the Selenium WebDriver API and the Chrome browser. It allows the WebDriver API to interact with the Chrome browser to automate web applications.

Here are some of the key features and components of ChromeDriver:

·         HTTP server: ChromeDriver includes an HTTP server that listens to incoming commands from the WebDriver API and sends back responses to the API. The HTTP server is responsible for managing the communication between the WebDriver API and the Chrome browser.

·         Chrome browser executable: ChromeDriver uses the Chrome browser executable to launch and control the Chrome browser. It provides a way to start a new instance of the Chrome browser, as well as to manage multiple browser windows and tabs.

·         ChromeDriver binary: The ChromeDriver binary is the main executable program that is used to interact with the Chrome browser. It is responsible for receiving commands from the WebDriver API, translating them into actions that can be performed by the Chrome browser, and sending back the results of those actions to the API.

·         ChromeDriver API: ChromeDriver provides its own API that can be used to interact with the Chrome browser. This API includes methods for navigating to URLs, finding elements on a page, interacting with form fields, taking screenshots, and more.

Overall, ChromeDriver is a crucial component of the Selenium WebDriver ecosystem that enables Selenium to automate interactions with the Chrome browser. It provides the bridge between the WebDriver API and the browser and provides a way to control the browser and perform actions on web applications.

 4.       Is chrome driver a class ?

Yes, ChromeDriver is a class in the Selenium WebDriver API. It is a concrete implementation of the WebDriver interface that provides the specific functionality needed to control the Chrome browser.

When you create an instance of the ChromeDriver class in your test script, you are creating a new instance of the ChromeDriver executable that is used to launch and control the Chrome browser. The ChromeDriver class provides methods for interacting with the browser, such as navigating to URLs, finding elements on a page, interacting with form fields, and more.

Here's an example of how you might create an instance of the ChromeDriver class in a Java test

import org.openqa.selenium.WebDriver;

import org.openqa.selenium.chrome.ChromeDriver;

 

public class MyTestScript {

    public static void main(String[] args) {

        // Set the path to the ChromeDriver executable

        System.setProperty("webdriver.chrome.driver", "/path/to/chromedriver");

 

        // Create a new instance of the ChromeDriver class

        WebDriver driver = new ChromeDriver();

 

        // Use the WebDriver to interact with the Chrome browser

        driver.get("https://www.google.com");

        driver.findElement(By.name("q")).sendKeys("Selenium");

        driver.findElement(By.name("btnK")).click();

 

        // Quit the browser

        driver.quit();

    }

}

In this example, we first set the path to the ChromeDriver executable using the System.setProperty method. We then create a new instance of the ChromeDriver class and assign it to a variable of type WebDriver. We can then use the WebDriver methods to interact with the Chrome browser, such as navigating to a URL using get, finding an element on the page using findElement, and interacting with the element using sendKeys and click.

So, ChromeDriver is a class in the Selenium WebDriver API that provides the specific functionality needed to control the Chrome browser.

5.       Can we talk about any get method which is an unimplemented method in webdriver and being implemented in Chromedriver ?

There is no specific get method in WebDriver that is unimplemented in ChromeDriver. Both WebDriver and ChromeDriver implement the get method as part of the Navigation interface.

The get method is used to navigate to a URL, and is implemented in both WebDriver and ChromeDriver as follows:

public void get(String url) {

    execute(DriverCommand.GET, ImmutableMap.of("url", url));

}

This method sends a DriverCommand.GET command to the browser driver, along with the URL to navigate to.

While ChromeDriver does provide additional functionality specific to the Chrome browser, such as the setDownloadPath method mentioned earlier, it does not typically include completely unimplemented versions of standard methods like get.

Let us talk in detail about 'get' method implementation in Chromedriver class  , EdgeDriver class etc from the unimplemented get method in Webdriver  !!

The get method in WebDriver is implemented by all browser-specific implementations of the WebDriver interface, including ChromeDriver, EdgeDriver, FirefoxDriver, etc. These browser-specific drivers provide their own implementation of the get method, which allows the driver to navigate to a specific URL.

Here's a closer look at how the get method is implemented in ChromeDriver and EdgeDriver:

ChromeDriver

In ChromeDriver, the get method is implemented in the ChromeDriver class, which extends the RemoteWebDriver class that implements the WebDriver interface. The get method in ChromeDriver looks like this:

public void get(String url) {

    Command command = new Command(getSessionId(), "get", ImmutableMap.of("url", url));

    execute(command);

}

This method overrides the get method from RemoteWebDriver, and sends a "get" command to the browser using the Command class. The getSessionId method retrieves the session ID of the current browser session, and the ImmutableMap specifies the URL to navigate to.

EdgeDriver

In EdgeDriver, the get method is also implemented in the EdgeDriver class, which extends the RemoteWebDriver class that implements the WebDriver interface. The get method in EdgeDriver looks like this:

public void get(String url) {

    execute(DriverCommand.GET, ImmutableMap.of("url", url));

}

This method also overrides the get method from RemoteWebDriver, and sends a "get" command to the browser driver using the DriverCommand class. The ImmutableMap specifies the URL to navigate to.

In both cases, the get method in the browser-specific driver simply sends a command to the browser to navigate to a specific URL, using the appropriate syntax for that driver. The get method is not an unimplemented method in WebDriver, but is rather implemented in each browser-specific driver.