Beginning iOS 5 Application Development

SUMMARY

This chapter demonstrated how to write a file to the file system of the iPhone and how to read it back. In addition, you saw how structured data can be represented using a property list and how you can programmatically work with a property list using a dictionary object. The next chapter shows you how to use databases to store more complex data.

EXERCISES

1. Describe the uses of the various subfolders contained within an application's folder.
2. What is the difference between the NSDictionary and NSMutableDictionary classes?
3. Name the paths of the Documents and tmp folders on a real device.
4. Name the class that provides in-app support for exporting documents from your application.
5. What key should be set in order to allow file sharing support for your application?
6. What key is used to register a new file type with iOS to inform it that your application is capable of handling it?

Answers to the exercises can be found in Appendix D.

WHAT YOU LEARNED IN THIS CHAPTER

TOPIC	KEY CONCEPTS
Subdirectories in each of the applications folders	Documents, Library, and tmp
Getting the path of the Documents folder	NSArray *paths = NSSearchPathForDirectoriesInDomains( NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDir = [paths objectAtIndex:0];
Getting the path of the tmp directory	-(NSString *) tempPath{ return NSTemporaryDirectory(); }
Checking whether a file ...