Handling WebElements

Handling web elements in any web-based application,iinvolves understanding how to locate and interact with these elements effectively using tools like Selenium WebDriver in Python. The process involves identifying the HTML structure of the web page and then using Selenium’s various methods to locate and manipulate elements like text boxes, buttons, links, dropdowns, etc.

Step-by-Step Guide to Handling Web Elements with Selenium in Python

Step 1: Set Up Your Environment

Ensure you have Python, Selenium, and the necessary WebDriver installed. If you haven’t set it up yet, you can refer to the earlier tutorial on setting up Selenium with Python and using webdriver_manager to handle driver dependencies.

Step 2: Identify Web Elements

To interact with web elements, you first need to identify them. Common methods provided by Selenium to locate elements include:

These methods return a WebElement object that you can interact with. For Visma or any other complex application, identifying elements accurately is crucial and might often require using CSS selectors or XPath expressions.

Finding web elements efficiently is a crucial skill for anyone using Selenium for web automation and testing. Web elements can be identified either manually by querying the DOM using tools like Google Chrome’s DevTools or by using automated recorders. Both methods have their uses, but understanding how to manually query the DOM through CSS selectors or XPath expressions gives you more control and precision, which is especially important for complex web applications

Using Google Chrome’s DevTools to Manually Inspect Elements

Google Chrome’s DevTools is an essential tool for web developers and testers. It allows you to inspect the HTML and CSS of a web page and experiment with changes in real-time. Here’s how to use it for finding web elements:

Open DevTools: Right-click on the webpage and select Inspect, or press Ctrl+Shift+I (or Cmd+Opt+I on Mac).

Inspect Elements: Hover over the webpage elements in the browser or use the inspect icon (a mouse cursor and box) in the top-left corner of DevTools to select an element directly on the page.

View and Copy Selectors: In the Elements tab, you can see the HTML structure of the page. Right-click on the highlighted element in the Elements panel, go to Copy, and choose Copy selector for a CSS selector or Copy XPath for an XPath. This gives you a string you can use directly in your Selenium scripts.

Why Learning to Manually Query the DOM is Important

Using Recorders for Generating Selectors

Recorders such as Selenium IDE or tools like Katalon Studio can automatically record your interactions with the web and generate the necessary selectors to reproduce these actions in a script. Here’s how you can use these tools:

Comparing Manual and Automated Methods

Learning Curve: Manual inspection requires understanding HTML, CSS, and possibly JavaScript, which is more demanding than using a recorder.

Accuracy and Reliability: Manual methods are often more reliable for complex and dynamic content.

Speed: Recorders can quickly generate a full set of scripts that can be a good starting point, especially for straightforward tasks.

In separate lesson it is explained how to find the best elements manually, like you query in SQL

Step 3: Interact with the Elements

Once you’ve identified the elements, you can perform various actions such as:

Example: Interacting with Visma

Let’s assume you need to log in to a Visma application(dutch ERP bookkeeping application), navigate to a specific page, and perform some actions. Here’s how you might code it:

from selenium import webdriver
from webdriver_manager.chrome import ChromeDriverManager
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.common.by import By

# Setup WebDriver
driver = webdriver.Chrome(ChromeDriverManager().install())

# Open the Visma login page
driver.get("https://login.visma.com")

# Wait for the login elements to be visible and interact with them
username = WebDriverWait(driver, 10).until(
    EC.visibility_of_element_located((By.NAME, "username"))
)
username.send_keys("your_username")

password = driver.find_element_by_name("password")
password.send_keys("your_password")

login_button = driver.find_element_by_id("login-button")
login_button.click()

# Navigate to a specific module
# Assume we wait until a specific element is clickable which navigates to the module
module_button = WebDriverWait(driver, 10).until(
    EC.element_to_be_clickable((By.ID, "module-navigation-button"))
)
module_button.click()

# Perform further actions, like filling out forms or processing data

# Close the browser after your tasks
driver.quit()

Tips for Effective Web Element Handling

Conclusion

Automating interactions with web applications like Google involves identifying and manipulating web elements effectively using Selenium WebDriver. This allows for robust automation scripts that can log in, input data, retrieve data, and navigate complex workflows within web applications. Remember, the key to successful automation is understanding the DOM structure of the application and writing resilient code that can handle changes and exceptions.