5 Best Ways to Set Window Size Using PhantomJS and Selenium WebDriver in Python

Rate this post

πŸ’‘ Problem Formulation: In test automation using Selenium with PhantomJS, it’s often necessary to specify the size of the browser window to ensure that elements are rendered correctly and tests are consistent. This article will outline five methods to set the size of the PhantomJS window in Selenium WebDriver using Python, essential for replicating user interactions on a webpage.

Method 1: Using set_window_size()

PhantomJS WebDriver provides the set_window_size() method to adjust the browser window size directly. It requires the desired width and height as integer parameters. This method is straightforward and integrates seamlessly within the Selenium testing script.

Here’s an example:

from selenium import webdriver

driver = webdriver.PhantomJS()
driver.set_window_size(1024, 768)

# Additional testing code goes here

driver.quit()

The output is an invisible browser window with a resolution of 1024×768 pixels.

This snippet is initializing a PhantomJS WebDriver instance, setting its window size to 1024 pixels in width and 768 pixels in height, and finally quitting the driver, effectively closing the browser window.

Method 2: Setting Window Size via Command-line Arguments

You can pass the window size as command-line arguments when initializing the PhantomJS driver. The --window-size argument is followed by the width and height values, which allows for setting the window size on driver instantiation.

Here’s an example:

from selenium import webdriver

service_args = [
    '--window-size=1280,800',
]

driver = webdriver.PhantomJS(service_args=service_args)

# Additional testing code goes here

driver.quit()

The output is an invisible browser window with a resolution of 1280×800 pixels.

This code first specifies the window size within a list of command-line arguments, then passes this list to the PhantomJS WebDriver during its initiation, setting the browser window to the specified size before any tests run.

Method 3: Using Desired Capabilities

Desired capabilities provide a way to configure various properties of the WebDriver, including the window size. By setting 'phantomjs.page.settings.width' and 'phantomjs.page.settings.height' in the capabilities, one can control the window size.

Here’s an example:

from selenium import webdriver

desired_cap = {
    'phantomjs.page.settings.width': '1366',
    'phantomjs.page.settings.height': '768'
}

driver = webdriver.PhantomJS(desired_capabilities=desired_cap)

# Additional testing code goes here

driver.quit()

The output is an invisible browser window with a resolution of 1366×768 pixels.

The snippet above sets the desired window size through the capabilities object by assigning values to width and height settings, which are then used to instantiate the PhantomJS WebDriver with those predefined window dimensions.

Method 4: Resize After Instantiation

If you need to change the window size after the WebDriver has already been instantiated, you can directly call the set_window_size() method on the driver object at any point in your test script to resize the window dynamically.

Here’s an example:

from selenium import webdriver

driver = webdriver.PhantomJS()

# Let's assume some operations are performed here

# Now resize the window
driver.set_window_size(1920, 1080)

# Continue with your operations that require a changed window size

driver.quit()

The output will be the browser window resizing to 1920×1080 pixels at the designated point in the script.

This code initializes the WebDriver, performs some operations, and then resizes the window to the new dimensions before continuing with the rest of the script. It’s ideal for tests requiring simulating various screen sizes or responsive layouts.

Bonus One-Liner Method 5: Maximize Window

In certain cases, you may want to run your tests with the window maximized. PhantomJS provides the maximize_window() function to simplify this task, although actual maximization may depend on the system PhantomJS is running on, as it is a headless browser.

Here’s an example:

from selenium import webdriver

# Initialize driver and maximize the window
driver = webdriver.PhantomJS()
driver.maximize_window()

# Additional testing code goes here

driver.quit()

While the code maximizes the window, the output’s actual dimensions may vary based on PhantomJS and the system it’s running on.

This approach quickly maximizes the browser window to the screen’s full size, which might be especially useful when trying to replicate a user’s experience on a full-screen browser without needing to specify the exact dimensions.

Summary/Discussion

  • Method 1: Using set_window_size(). Strengths include ease of use and direct integration with Selenium. Weaknesses: none significant.
  • Method 2: Command-line Arguments. Strengths include setting the size upon initialization, which may be necessary for certain tests. Weaknesses: less flexible as it’s not easily changeable after the driver starts.
  • Method 3: Desired Capabilities. Strengths include a highly configurable setup. Weaknesses: it’s a bit more verbose and can be overkill for simple size adjustments.
  • Method 4: Resize After Instantiation. Strengths: allows dynamic resizing, useful for adaptive/responsive test cases. Weaknesses: might add unnecessary complexity if resizing is not needed during a test.
  • Method 5: Maximize Window. Strengths: easiest way to replicate a full-screen experience. Weaknesses: actual size might be unpredictable, and some web elements’ behaviors might be different on full screen.