You are previewing Learning iPhone Programming.

Learning iPhone Programming

Cover of Learning iPhone Programming by Alasdair Allan Published by O'Reilly Media, Inc.
  1. Learning iPhone Programming
    1. SPECIAL OFFER: Upgrade this ebook with O’Reilly
    2. A Note Regarding Supplemental Files
    3. Preface
      1. Who Should Read This Book?
      2. What Should You Already Know?
      3. What Will You Learn?
      4. What’s in This Book?
      5. Conventions Used in This Book
      6. Using Code Examples
      7. How to Contact Us
      8. Safari® Books Online
      9. Acknowledgments
    4. 1. Why Go Native?
      1. The Pros and Cons
      2. The Release Cycle
      3. Build It and They Will Come
    5. 2. Becoming a Developer
      1. Registering As an iPhone Developer
      2. Enrolling in the iPhone Developer Program
      3. The Apple Developer Connection
      4. Installing the iPhone SDK
      5. Preparing Your iPhone or iPod touch
    6. 3. Your First iPhone App
      1. Objective-C Basics
      2. Creating a Project
    7. 4. Coding in Objective-C
      1. Declaring and Defining Classes
      2. Memory Management
      3. Fundamental iPhone Design Patterns
      4. Conclusion
    8. 5. Table-View-Based Applications
      1. Simplifying the Template Classes
      2. Creating a Table View
      3. Building a Model
      4. Connecting the Controller to the Model
      5. Adding Navigation Controls to the Application
      6. Adding a City View
      7. Edit Mode
    9. 6. Other View Controllers
      1. Utility Applications
      2. Tab Bar Applications
      3. Modal View Controllers
      4. The Image Picker View Controller
    10. 7. Connecting to the Network
      1. Detecting Network Status
      2. Embedding a Web Browser in Your App
      3. Sending Email
      4. Getting Data from the Internet
    11. 8. Handling Data
      1. Data Entry
      2. Parsing XML
      3. Parsing JSON
      4. Regular Expressions
      5. Storing Data
    12. 9. Distributing Your Application
      1. Adding Missing Features
      2. Building and Signing
      3. Submitting to the App Store
      4. Reasons for Rejection
    13. 10. Using Sensors
      1. Hardware Support
      2. Using the Camera
      3. The Core Location Framework
      4. Using the Accelerometer
      5. Using the Digital Compass
      6. Accessing the Proximity Sensor
      7. Using Vibration
    14. 11. Geolocation and Mapping
      1. User Location
      2. Annotating Maps
    15. 12. Integrating Your Application
      1. Application Preferences
      2. Custom URL Schemes
      3. Media Playback
      4. Using the Address Book
    16. 13. Other Native Platforms
      1. PhoneGap
      2. MonoTouch
    17. 14. Going Further
      1. Cocoa and Objective-C
      2. Web Applications
      3. Core Data
      4. Push Notifications
      5. In-App Purchase
      6. Core Animation
      7. Game Kit
      8. Writing Games
      9. Look and Feel
      10. Hardware Accessories
    18. Index
    19. About the Author
    20. Colophon
    21. SPECIAL OFFER: Upgrade this ebook with O’Reilly
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Parsing XML

The two widely used methods for parsing an XML document are SAX and DOM. A SAX (Simple API for XML) parser is event-driven. It reads the XML document incrementally and calls a delegate method whenever it recognizes a token. Events are generated at the beginning and end of the document, and the beginning and end of each element. A DOM (Document Object Model) parser reads the entire document and forms a tree-like corresponding structure in memory. You can then use the XPath query language to select individual nodes of the XML document using a variety of criteria.

Most programmers find the DOM method more familiar and easier to use; however, SAX-based applications are generally more efficient, run faster, and use less memory. So, unless you are constrained by system requirements, the only real factor when deciding to use SAX or DOM parsers comes down to preference.

If you want to know more about XML, I recommend Learning XML, Second Edition by Erik T. Ray (O’Reilly) as a good place to start.

Parsing XML with libxml2

We met the libxml2 parser and Matt Gallagher’s XPath wrappers in the preceding chapter, and my advice is to use these wrappers if you want to do DOM-based parsing of XML on the iPhone or iPod touch.

See the sidebar Using the XPath Wrappers in Chapter 7 for instructions on adding the XPathQuery wrappers to your project.

The wrappers offer two methods. The only difference between the two is that one expects an HTML document and is therefore less strict about what constitutes ...

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