Getting Started with PhantomJS

By : Aries beltran

Getting Started with PhantomJS

By: Aries beltran

Overview of this book

PhantomJS is a headless WebKit browser with JavaScript API that allows you to create new ways to automate web testing. PhantomJS is currently being used by a large number of users to help them integrate headless web testing into their development processes. It also gives you developers a new framework to create web-based applications, from simple web manipulation to performance measurement and monitoring.A step step-by by-step guide that will help you develop new tools for solving web and testing problems in an effective and quick way. The book will teach you how to use and maximize PhantomJS to develop new tools for web scrapping, web performance measurement and monitoring, and headless web testing. This book will help you understand PhantomJS’ scripting API capabilities and strengths.This book starts by looking at PhantomJS’ JavaScript API, features, and basic execution of scripts. Throughout the book, you will learn details to help you write scripts to manipulate web documents and fully create a web scrapping tool.Through its practical approach, this book strives to teach you by example, where each chapter focuses on the common and practical usage of PhantomJS, and how to extract meaningful information from the web and other services.By the end of the book, you will have acquired the skills to enable you to use PhantomJS for web testing, as well as learning the basics of Jasmine, and how it can be used with PhantomJS.

Preface

What this book covers

What you need for this book

Free Chapter

1. Getting Started

Downloading PhantomJS

Building PhantomJS from source

Working with PhantomJS

PhantomJS JavaScript API

The phantom object

The command-line arguments

Writing PhantomJS scripts

Summary

2. Manipulating Page Content

Opening a web page

Playing with DOM elements

Simulating mouse clicks

Working with form fields

Summary

3. Handling Events and Callbacks

Listening to page events

Capturing alert messages

Answering prompt messages

Responding to confirm pop ups - OK or Cancel

Performing user events

Summary

4. Capturing Errors

Handling PhantomJS errors

Capturing page script errors

Anticipating the page loading error

Exiting with error codes

Summary

5. Grabbing Pages

Undocumented supported image format

Screenshot dimensions

Saving web pages as PDFs

Summary

6. Accessing Location-based Services

Checking a location based on IP address

Getting driving directions

Looking up for pizza delivery establishments

Summary

7. Working with Files

PhantomJS FileSystem API

Reading files

Writing files

Character encoding

Summary

8. Cookies

Summary

9. External JavaScript

Modules

Using the object-oriented modules

Using third-party JavaScript libraries

Summary

10. Testing with PhantomJS

What is unit testing?

Unit testing with Jasmine

Summary

11. Maximizing PhantomJS

CasperJS

GhostDriver

Screenshots, web metrics, and more

Summary

Index

Customer Reviews

5 star

4 star

3 star

2 star

1 star

Answering prompt messages

Aside from alert messages, there are prompt messages that ask users to input their answer into a single text field. To handle this kind of dialog box from web pages, PhantomJS allows us to handle and answer back to this dialog prompts using the onPrompt callback.

page.onPrompt = function(message, defaultVal) {
  if (message === 'How old are you?') {
    return '18';
  }
  
  return defaultVal;
};

The onPrompt function callback receives two parameters. The first parameter is the message to be displayed in the prompt dialog; this normally asks a question back to the user. The second parameter is the default value or answer.

Getting Started with PhantomJS

By : Aries beltran

Getting Started with PhantomJS

By: Aries beltran

Overview of this book

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Getting Started with PhantomJS

Answering prompt messages