DAPreferences Class Reference

#import <DAPreferences.h>

List of all members.

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Detailed Description

Alternative preferences structure for DownAndOut[tm].

The normal storage for preferences for screen-saver modules is in ~/Library/Preferences/ByHost, with the subsequent path hashed from machine-dependent data. This was not satisfactory to those who specified DownAndOut, as they wanted a quick way to deposit a DownAndOut configuration into any user's preference folder.

This class tracks a mutable-dictionary document, effectively duplicating the NSUserDefaults mechanism with the preferences in the dictionary, and the file in the assigned path. It knows when it's dirty, and can flush itself out to the file. It provides key accessors for the common data types.

Bug:

DAPreferences ought to support usage as a singleton.

Definition at line 32 of file DAPreferences.h.

Public Member Functions
(id)	- initWithDictionary:forPath:
	Designated initializer for a new preference file.
(id)	- initWithPath:
	Designated initializer for existing preference file, when there are no default values.
(id)	- initWithDefaults:
	Initialize the DownAndOut[tm] preferences with defaults.
(void)	- flushToFile
	Write the preference file if the contents have changed.
(int)	- integerForKey:
	Access integer value for a preference.
(void)	- setInteger:forKey:
	Set integer value for a preference.
(id)	- objectForKey:
	Access object value for a preference.
(void)	- setObject:forKey:
	Set object value for a preference.
(BOOL)	- boolForKey:
	Access BOOL value for a preference.
(void)	- setBool:forKey:
	Set Boolean value for a preference.
(NSData *)	- dataForKey:
	Access NSData stored under a key.
(NSString *)	- stringForKey:
	Access NSString stored under a key.
(void)	- removeObjectForKey:
	Remove a preference from the dictionary.
(void)	- dealloc [implementation]
	Unremarkable deallocator.
Protected Attributes
NSMutableDictionary *	prefs
	the preferences dictionary
NSString *	path
	path to preferences file
BOOL	dirty
	whether prefs have changed since last write.

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Member Function Documentation

- (BOOL) boolForKey: (NSString *)  aKey

Access BOOL value for a preference. Parameters: aKey  NSString, the preference sought. Return values: YES  if the preference existed and was YES. NO  if the preference did not exist, or was NO. Definition at line 95 of file DAPreferences.m. References objectForKey:.

- (NSData *) dataForKey: (NSString *)  aKey

Access NSData stored under a key. The inverse of this operation is setObject:forKey: Parameters: aKey  NSString, the preference sought. Return values: NSData  the value of the preference, if it exists and is NSData. nil  if the preference did not exist, or was not NSData. Definition at line 106 of file DAPreferences.m. References objectForKey:.

- (void) flushToFile

Write the preference file if the contents have changed. This method writes the preferences dictionary to the designated preference file atomically, if any preference has changed since the last write. Definition at line 65 of file DAPreferences.m. References dirty, and prefs.

- (id) initWithDefaults: (NSDictionary *)  initial

Initialize the DownAndOut[tm] preferences with defaults. This method hard-codes a path to edu.uchicago.DownAndOut[tm].plist in the user's preferences folder. An attempt is made to read preferences from that file with initWithPath:. If that fails, that path and the given initial preferences are used in initWithDictionary:forPath:. Parameters: initial  NSDictionary, the values the preferences are to have if none have been set before. Return values: self  if the preference file exists and could be read. id  a fresh DAPreferences object if no usable preference file existed. Definition at line 49 of file DAPreferences.m. References initWithPath:.

- (id) initWithDictionary: (NSDictionary *)  initial forPath: (NSString *)  fullPath

Designated initializer for a new preference file. Creates a DAPreferences ex nihilo, with preference state and a path to a file, which will be created or overwritten when the preferences are written. This method is for internal use only, as there it makes little sense to do this without more context. Parameters: initial  NSDictionary containing the current state of the preferences. fullPath  NSString, path to the preference file. Return values: self  always. Definition at line 29 of file DAPreferences.m. References dirty, path, and prefs.

- (id) initWithPath: (NSString *)  fullPath

Designated initializer for existing preference file, when there are no default values. The dictionary file at fullPath is read and made the preference set. Changes will be written back to fullPath. Parameters: fullPath  NSString, path to the preference file. Return values: self  if a dictionary was read from fullPath. nil  if fullPath was not a dictionary file. Definition at line 37 of file DAPreferences.m. References dirty, path, and prefs. Referenced by initWithDefaults:.

- (int) integerForKey: (NSString *)  aKey

Access integer value for a preference. Parameters: aKey  NSString, the preference sought. Return values: int  value for the preference, including zero. zero  if the preference did not exist. Definition at line 73 of file DAPreferences.m. References objectForKey:.

- (id) objectForKey: (NSString *)  aKey

Access object value for a preference. Parameters: aKey  NSString, the preference sought. Return values: id  the value for the preference. nil  if the preference did not exist. Definition at line 84 of file DAPreferences.m. References prefs. Referenced by boolForKey:, dataForKey:, integerForKey:, and stringForKey:.

- (void) removeObjectForKey: (NSString *)  aKey

Remove a preference from the dictionary. Marks the preference dictionary dirty. Parameters: aKey  NSString, the preference to delete. Definition at line 118 of file DAPreferences.m. References dirty, and prefs.

- (void) setBool: (BOOL)  aBool forKey: (NSString *)  aKey

Set Boolean value for a preference. Marks the preference dictionary dirty. Parameters: aBool  BOOL, the value to set. aKey  NSString, the preference to set. Definition at line 101 of file DAPreferences.m. References setObject:forKey:.

- (void) setInteger: (int)  anInt forKey: (NSString *)  aKey

Set integer value for a preference. Marks the preference dictionary dirty. Parameters: anInt  int, the value to set. aKey  NSString, the preference to set. Definition at line 79 of file DAPreferences.m. References setObject:forKey:.

- (void) setObject: (id)  value forKey: (NSString *)  aKey

Set object value for a preference. Marks the preference dictionary dirty. Parameters: value  id, the value to set. aKey  NSString, the preference to set. Definition at line 89 of file DAPreferences.m. References dirty, and prefs. Referenced by setBool:forKey:, and setInteger:forKey:.

- (NSString *) stringForKey: (NSString *)  aKey

Access NSString stored under a key. The inverse of this operation is setObject:forKey: Parameters: aKey  NSString, the preference sought. Return values: NSString  the value of the preference, if it exists and is NSString. nil  if the preference did not exist, or was not NSString. Definition at line 112 of file DAPreferences.m. References objectForKey:.

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The documentation for this class was generated from the following files:

• /Volumes/Experimental/Users/fritza/U Chicago/DownAndOut/DAPreferences.h
• /Volumes/Experimental/Users/fritza/U Chicago/DownAndOut/DAPreferences.m

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