Using Playwright for UI Automation: Handling Dialogs, File Uploads, and Executing JavaScript

UI automation typically involves interacting with page elements like dialogs, file inputs, and executing scripts; the following examples show how to accomplish these tasks using the Playwright library in Python.

1. Handling Dialogs

from playwright.sync_api import sync_playwright
with sync_playwright() as playwright:
    browser = playwright.chromium.launch()
    page = browser.new_page()
    # Handle dialog
    page.on('dialog', lambda dialog: dialog.dismiss())  # Auto‑close dialog
    page.goto('https://example.com')
    page.click('button')
    browser.close()

The code registers a listener for the dialog event and automatically dismisses any popup that appears.

2. Uploading Files

a. Single file upload

from playwright.sync_api import sync_playwright
with sync_playwright() as playwright:
    browser = playwright.chromium.launch()
    page = browser.new_page()
    file_path = '/path/to/your/file.txt'
    page.goto('https://example.com')
    page.click('input[type=file]')
    page.set_input_files('input[type=file]', file_path)
    browser.close()

b. Batch upload of multiple files

import os
from playwright.sync_api import sync_playwright

def upload_files(file_paths):
    with sync_playwright() as playwright:
        browser = playwright.chromium.launch()
        page = browser.new_page()
        for file_path in file_paths:
            file_name = os.path.basename(file_path)
            page.goto('https://example.com/upload')
            page.wait_for_selector('input[type=file]')
            page.set_input_files('input[type=file]', file_path)
            page.wait_for_load_state()
            page.click('input[type=submit]')
            print(f'Uploaded file: {file_name}')
        browser.close()

file_paths = [
    '/path/to/file1.txt',
    '/path/to/file2.txt',
    '/path/to/file3.txt',
]
upload_files(file_paths)

This function iterates over a list of file paths, uploads each one, waits for completion, and prints the uploaded file name.

c. Batch upload from a folder

import os
from playwright.sync_api import sync_playwright

def upload_files_from_folder(folder_path):
    with sync_playwright() as playwright:
        browser = playwright.chromium.launch()
        page = browser.new_page()
        file_paths = []
        for root, dirs, files in os.walk(folder_path):
            for file in files:
                file_paths.append(os.path.join(root, file))
        for file_path in file_paths:
            file_name = os.path.basename(file_path)
            page.goto('https://example.com/upload')
            page.wait_for_selector('input[type=file]')
            page.set_input_files('input[type=file]', file_path)
            page.wait_for_load_state()
            page.click('input[type=submit]')
            print(f'Uploaded file: {file_name}')
        browser.close()

folder_path = '/path/to/folder'
upload_files_from_folder(folder_path)

The script walks through a directory, collects all file paths, and uploads each file using the same process as the batch upload example.

3. Executing JavaScript

from playwright.sync_api import sync_playwright
with sync_playwright() as playwright:
    browser = playwright.chromium.launch()
    page = browser.new_page()
    # Execute JavaScript
    page.goto('https://example.com')
    result = page.evaluate('1 + 2')
    print(result)  # Output: 3
    browser.close()

Here page.evaluate() runs a JavaScript expression in the page context and returns the result.

These examples illustrate how Playwright can be used to automate common UI tasks; developers can adapt and extend the code to fit their specific testing or automation needs.