Book Image

Mastering PhoneGap Mobile Application Development

By : Kerri Shotts
Book Image

Mastering PhoneGap Mobile Application Development

By: Kerri Shotts

Overview of this book

PhoneGap is a useful and flexible tool that enables you to create complex hybrid applications for mobile platforms. In addition to the core technology, there is a large and vibrant community that creates third-party plugins that can take your app to the next level. This book will guide you through the process of creating a complex data-driven hybrid mobile application using PhoneGap, web technologies, and third-party plugins. A good foundation is critical, so you will learn how to create a useful workflow to make development easier. From there, the next version of JavaScript (ES6) and the CSS pre-processor SASS are introduced as a way to simplify creating the look of the mobile application. Responsive design techniques are also covered, including the flexbox layout module. As many apps are data-driven, you'll build an application throughout the course of the book that relies upon IndexedDB and SQLite. You'll also download additional content and address how to handle in-app purchases. Furthermore, you’ll build your own customized plugins for your particular use case. When the app is complete, the book will guide you through the steps necessary to submit your app to the Google Play and Apple iTunes stores.
Table of Contents (19 chapters)
Mastering PhoneGap Mobile Application Development
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Handling database upgrades


As it may be already apparent, IndexedDB databases are tagged with a version number. Whenever the app requests a database version that is newer than the one the user actually has, onupgradeneeded will be called so that the app has a chance to modify the database.

Note

The snippets in this section are located at snippets/07/ex3-upgrade-database/* in the code package of this book. When using the interactive snippet playground, select 7: IndexedDB and examples 3a to 3b

Thankfully, onupgradeneeded is provided with the old version number of the database and the desired version number of the database, otherwise we'd have difficulty deciding what needed to be changed. With this information, we can upgrade our database pretty simply. First, let's modify our openDatabase function slightly to the following:

// Example Snippet 3a
function openDatabase({name, version, onopen, onerror, onupgrade}) {
    let req = indexedDB.open(name, version);
    req.onerror = function(evt) ...