Comprehensive Guide to Understanding Selenium | What Is Selenium ?

What is Selenium?

Selenium is a suite of tools particularly used for automating web programs for trying out functions. It gives a way to have interaction with internet elements and perform moves such as clicking buttons, filling forms, and navigating thru web pages programmatically. Selenium supports more than one programming languages like Java, Python, C#, Ruby, and JavaScript, making it flexible and broadly used throughout extraordinary development environments.

Selenium is a set of software utilities for automating the web application testing across the multiple browsers and operating systems. It supports Java, C#, Python, Ruby, and IS Java Script among other languages of programming.

Selenium comprises several components: 

•  Selenium WebDriver: It is an application that offers a more progressive and efficient way of testing web applications as opposed to browser automation. 
•  Selenium IDE: A cross-browser plugin that records/plays functional tests on Chrome and Firefox. It is helpful for writing the trivial test script to reproduce a bug. 
•  Selenium Grid: Enables you to perform tests on two or more machines within distinct environments, thus, making the test suite fast.

Components of Selenium:

1. Selenium IDE (Integrated Development Environment):

Selenium IDE is a browser extension used for recording and playback of interactions with the browser. It's in most cases used for brief check prototyping and exploratory checking out.

Selenium IDE is available for Chrome and Firefox browsers.

2. Selenium WebDriver:

Selenium WebDriver is the center factor of Selenium. It provides a programming interface for creating and executing test scripts.

WebDriver immediately communicates with the browser the usage of the browser's native automation help (e.G., Chrome DevTools Protocol for Chrome).

WebDriver helps more than one programming languages, permitting testers to jot down scripts of their favored language.

3. Selenium Grid:

Selenium Grid is used for parallel execution of take a look at scripts across multiple browsers, working structures, and gadgets.

It permits dispensing checks throughout a community of machines, enhancing check execution speed and performance.

How Selenium Works:

 Selenium consists of several components that work together:

Selenium WebDriver interacts with browsers with the help of Browser Drivers that are made for every Browser. The interaction follows this pattern:

1. Setting Up WebDriver 

However, before using Selenium, the WebDriver wants to be initiated for the actual browser to be automated. 

 2. Writing a Basic Script 

 Here’s an example of a basic Selenium script in Python: 

 

 from selenium import webdriver 

 from selenium. webdriver. common. keys import Keys 

 #This first step is to initiate the WebDriver i. e. chrome driver 

 driver = webdriver. Chrome(executable_path='/path/to/chromedriver') 

 # Mainly to open a web page 

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

 #Make it clear where to find an element (e. g. , the search box). 

 search_box = driver. find_element_by_name("q") 

 # Affect the element by engaging in an activity there (e. g. , type in a search string, then press the ‘Search’ button). 

 search_box. send_keys("Selenium WebDriver") 

 search_box. send_keys(Keys. RETURN) 

 # Take a few seconds to get the results 

 driver. implicitly_wait(10) 

 # Close the browser 

 driver. quit() 

 

3. Interacting with Web Elements 

 Locating Elements 

 You can locate web elements using various methods:

•  By ID: find_element_by_id("element_id") 
•  By Name: find_element_by_name("element_name") 
•  By Class Name: find_element_by_class_name("class_name") 
•  By Tag Name: find_element_by_tag_name("tag_name") 
•  By CSS Selector: find_element_by_css_selector("css_selector") 
•  By XPath: find_element_by_xpath("xpath_expression") 

 Performing Actions :

 Once you have located an element, you can perform actions on it

•  Clicking: element. click() 
•  Typing: element. send_keys("text") 
•  Clearing: element. clear()  
•  Selecting from a Dropdown: By subclassing Select class from selenium. webdriver. support. ui. 

4. Handling Dynamic Content 

Web pages always have the characteristic that they load the complete content dynamically. Selenium provides mechanisms to handle these cases: 

•  Implicit Waits: Wait for a desired amount of time for elements to come in. 

 driver. implicitly_wait(10)  # seconds 

•  Explicit Waits: One has to wait until the occurrence of one event before moving to another. 

 from selenium. webdriver. common. by import By 

 from selenium. webdriver. support. ui import WebDriverWait 

 from selenium. webdriver. support import expected_conditions as EC 

 

 element = WebDriverWait(driver, 10). until( 

 EC. presence_of_element_located((By. ID, "myDynamicElement")) 

 )  

5. Conducting Test Parallel with Selenium Grid 

Selenium Grid helps in the distribution of the testing process across various machines and different browsers. I saw that you create a central point for the management of the process and the points where the tests are carried out. 

•  Hub: It is a point at the center at which tests are uploaded. 
•  Nodes: Test performing machines.

Advantages of Selenium:

• Cross-browser Compatibility: Selenium helps more than one browsers like Chrome, Firefox, Safari, Edge, etc., ensuring the consistency of web packages throughout one-of-a-kind browsers.
• Language Support: Selenium gives bindings for famous programming languages, allowing testers to write down test scripts of their desired language.
• Open Source: Selenium is open-supply software, freely to be had to be used and modification through the network.
• Parallel Execution: Selenium Grid lets in executing tests in parallel, reducing test execution time and improving performance.
• Integration: Selenium integrates nicely with other testing frameworks and gear, making it suitable for various testing necessities.

Limitations of Selenium:

• Limited Support for Non-Web Applications: Selenium is often designed for testing net programs and lacks sturdy support for testing desktop and cell applications.
• Complexity: Writing and preserving Selenium test scripts may be complicated, particularly for massive and dynamic internet applications.
• Dependency on Browser Versions: Selenium's compatibility with distinct browser variations may additionally range, requiring frequent updates to ensure compatibility.
• No Built-in Reporting: Selenium lacks integrated reporting capabilities, requiring integration with outside reporting gear for generating check reports.

Here's a list of commonly used Selenium WebDriver commands along with a brief description of each:

Navigation Commands:

• get(String url): Load a new web page in the current browser window.
• navigate().to(String url): Load a new web page in the current browser window.

Element Locators:

• findElement(By locator): Find the first element within the current page using the given locator strategy.
• findElements(By locator): Find all elements within the current page using the given locator strategy.

Element Interaction:

• click(): Click on an element.
• sendKeys(CharSequence... keysToSend): Simulate typing into an element.
• clear(): Clear the content of an input field.

Element State:

• isEnabled(): Check if the element is enabled or not.
• isSelected(): Check if the element is selected or not.
• isDisplayed(): Check if the element is displayed or not.

Element Information:

• getText(): Get the visible (i.e., not hidden by CSS) text of the element.
• getAttribute(String attributeName): Get the value of the given attribute of the element.

Browser Interaction:

• close(): Close the current window, quitting the browser if it's the last window currently open.
• quit(): Quit the driver and close all associated windows.

Alert Interaction:

• switchTo().alert(): Switch the focus to an alert popup.
• accept(): Accept the alert.
• dismiss(): Dismiss the alert.

Window Handling:

• getWindowHandle(): Return a unique identifier for the current window.
• getWindowHandles(): Return a set of window handles which can be used to iterate over all open windows of this WebDriver instance.

Below are some commonly used locator strategies in Selenium WebDriver along with a brief description of each:

ID Locator:

Syntax: By.id(String id)

Description: Locates elements by their unique ID attribute value.

Name Locator:

Syntax: By.name(String name)

Description: Locates elements by their name attribute value.

Class Name Locator:

Syntax: By.className(String className)

Description: Locates elements by their CSS class name.

Tag Name Locator:

Syntax: By.tagName(String tagName)

Description: Locates elements by their HTML tag name.

Link Text Locator:

Syntax: By.linkText(String linkText)

Description: Locates <a> elements (links) by their visible text.

Partial Link Text Locator:

Syntax: By.partialLinkText(String partialLinkText)

Description: Locates <a> elements (links) by partial visible text.

CSS Selector Locator:

Syntax: By.cssSelector(String cssSelector)

Description: Locates elements by CSS selector syntax.

XPath Locator:

Syntax: By.xpath(String xpathExpression)

Description: Locates elements using XPath expressions, which allow for more complex selection criteria.

These locator strategies can be used with methods like findElement(By locator) and findElements(By locator) to locate and interact with elements on a web page using Selenium WebDriver. Depending on the specific element and its attributes, you may choose the most appropriate locator strategy to ensure reliable and maintainable test scripts.

These are just some of the most usually used commands in Selenium WebDriver. Depending on your checking out situation and necessities, you can want to explore additional commands and methods supplied by the Selenium WebDriver API.

Example: Google Search Automation

This script will open a Chrome browser, navigate to Google, perform a search for "Selenium WebDriver", and then print the titles of the search results.

Requirements:

• Python Installed: Make sure you have Python installed on your system.
• Selenium Library: Install the Selenium library using pip: pip install selenium
• ChromeDriver: Download ChromeDriver from here and ensure it's accessible via your system’s PATH or specify the path explicitly in your script.

from selenium import webdriver
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
# Set up the WebDriver (e.g., for Chrome)
driver = webdriver.Chrome(executable_path='/path/to/chromedriver')
try:
    # Open Google
    driver.get("https://www.google.com")
    # Find the search box
    search_box = driver.find_element(By.NAME, "q")
    # Enter a search query
    search_box.send_keys("Selenium WebDriver")
    search_box.send_keys(Keys.RETURN)
    # Wait for the search results to load and display the results
    WebDriverWait(driver, 10).until(EC.presence_of_element_located((By.ID, "search")))
    # Find all search result titles
    titles = driver.find_elements(By.XPATH, "//h3")
    # Print the titles of the search results
    for title in titles:
        print(title.text)
finally:
    # Close the browser
    driver.quit()

Explanation: 

•  Import Statements: The required modules of Selenium needs to be imported. 
•  Set Up WebDriver: We must begin the WebDriver with Chrome. In the CASE section, replace ‘/path/to/chromedriver’ with the path of the ChromeDriver application. 
•  Open Google: Use driver. gets to go to the address of Google’s home page. 
•  Find Search Box: Use the find_element method within By the locate the search box. NAME. 
•  Perform Search: Type the phrase “Selenium WebDriver” into the search engine’s textbox and then click the ‘search’ button. 
•  Wait for Results: Check using WebDriverWait and Explicitly wait for condition that search results have been loaded. presence_of_element_located. 
•  Extract Titles: Use find_elements with By to identify the titles of the search results. XPATH and print them. 
•  Close Browser: Make it certain that the browser is closed after the successful execution of the script using driver. use quit() in a finally block so that it would be executed many a time if at all an error has occurred. 

 In this example, the basic steps of Selenium have been shown, where the simple web page is opened, and some actions are performed on the page, and information is scraped off from the page.

Overall, Selenium is a effective device for automating net application testing and is widely adopted in the software trying out community for its flexibility, scalability, and open-source nature.