You are previewing Building iPhone Apps with HTML, CSS, and JavaScript.

Building iPhone Apps with HTML, CSS, and JavaScript

Cover of Building iPhone Apps with HTML, CSS, and JavaScript by Jonathan Stark Published by O'Reilly Media, Inc.
  1. Building iPhone Apps with HTML, CSS, and JavaScript
  2. Dedication
  3. A Note Regarding Supplemental Files
  4. Preface
    1. Who Should Read This Book
    2. What You Need to Use This Book
    3. Conventions Used in This Book
    4. Using Code Examples
    5. Safari® Books Online
    6. How to Contact Us
    7. Acknowledgments
  5. 1. Getting Started
    1. Web Apps Versus Native Apps
      1. What Is a Web App?
      2. What Is a Native App?
      3. Pros and Cons
      4. Which Approach Is Right for You?
    2. Web Programming Crash Course
      1. Intro to HTML
      2. Intro to CSS
      3. Intro to JavaScript
  6. 2. Basic iPhone Styling
    1. First Steps
      1. Preparing a Separate iPhone Stylesheet
      2. Controlling the Page Scaling
    2. Adding the iPhone CSS
    3. Adding the iPhone Look and Feel
    4. Adding Basic Behavior with jQuery
    5. What You’ve Learned
  7. 3. Advanced iPhone Styling
    1. Adding a Touch of Ajax
    2. Traffic Cop
    3. Simple Bells and Whistles
    4. Roll Your Own Back Button
    5. Adding an Icon to the Home Screen
    6. Full Screen Mode
      1. Changing the Status Bar
      2. Providing a Custom Startup Graphic
    7. What You’ve Learned
  8. 4. Animation
    1. With a Little Help from Our Friend
    2. Sliding Home
    3. Adding the Dates Panel
    4. Adding the Date Panel
    5. Adding the New Entry Panel
    6. Adding the Settings Panel
    7. Putting It All Together
    8. Customizing jQTouch
    9. What You’ve Learned
  9. 5. Client-Side Data Storage
    1. localStorage and sessionStorage
      1. Saving User Settings to localStorage
      2. Saving the Selected Date to sessionStorage
    2. Client-Side Database
      1. Creating a Database
      2. Inserting Rows
      3. Selecting Rows and Handling Result Sets
      4. Deleting Rows
    3. What You’ve Learned
  10. 6. Going Offline
    1. The Basics of the Offline Application Cache
    2. Online Whitelist and Fallback Options
    3. Creating a Dynamic Manifest File
    4. Debugging
      1. The JavaScript Console
      2. The Application Cache Database
    5. What You’ve Learned
  11. 7. Going Native
    1. Intro to PhoneGap
      1. Using the Screen’s Full Height
      2. Customizing the Title and Icon
      3. Creating a Startup Screen
    2. Installing Your App on the iPhone
    3. Controlling the iPhone with JavaScript
      1. Beep, Vibrate, and Alert
      2. Geolocation
      3. Accelerometer
    4. What You’ve Learned
  12. 8. Submitting Your App to iTunes
    1. Creating an iPhone Distribution Provisioning Profile
    2. Installing the iPhone Distribution Provisioning Profile
    3. Renaming the Project
    4. Prepare the Application Binary
    5. Submit Your App
    6. While You Wait
    7. Further Reading
  13. Index
  14. About the Author
  15. Colophon
  16. Copyright
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Chapter 5. Client-Side Data Storage

Most software applications need to store data in some sort of persistent fashion in order to be useful. When it comes to web apps, this task has traditionally been handled either with a server-side database or cookies set in the browser. With the advent of HTML5, web developers now have a few more options: localStorage, sessionStorage, and client-side databases.

localStorage and sessionStorage

localStorage and sessionStorage (collectively referred to as key/value storage) are very similar to cookies in that they allow you to use JavaScript to set name/value pairs that you can then retrieve across multiple page reloads.

Unlike cookies, however, localStorage and sessionStorage data is not sent across the wire with the browser request—it lives entirely in the client. Therefore, it’s feasible to store much more data than you would want to with cookies.

Note

At the time of this writing, browser size limits for localStorage and sessionStorage are still in flux.

Functionally, localStorage and sessionStorage are the same. They differ only in terms of persistence and scope:

localStorage

Data is saved even after the window is closed and is available to all windows (or tabs) that are loaded from the same source (must be the same domain name, protocol, and port). This is useful for things like application preferences.

sessionStorage

Data is stored with the window object. Other windows/tabs are not aware of the values, and the data is discarded when the window/tab is ...

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