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CoreFoundation Framework Reference Preferences Utilities Reference

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Preferences Utilities Reference

Inheritance


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Conforms To


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Import Statement


Swift

import CoreFoundation

Objective-C

@import CoreFoundation;

Core Foundation provides a simple, standard way to manage user (and application) preferences. Core Foundation stores preferences as key-value pairs that are assigned a scope using a combination of user name, application ID, and host (computer) names. This makes it possible to save and retrieve preferences that apply to different classes of users. Core Foundation preferences is useful to all applications that support user preferences. Note that modification of some preferences domains (those not belonging to the “Current User”) requires root privileges (or Admin privileges prior to OS X v10.6)—see Authorization Services Programming Guide for information on how to gain suitable privileges.

Unlike some other Core Foundation types, CFPreferences is not toll-free bridged to its corresponding Cocoa Foundation framework class (NSUserDefaults). CFPreferences is thread-safe.

Functions

  • Obtains a preference value for the specified key and application.

    Declaration

    Swift

    func CFPreferencesCopyAppValue(_ key: CFString!, _ applicationID: CFString!) -> CFPropertyList!

    Objective-C

    CFPropertyListRef CFPreferencesCopyAppValue ( CFStringRef key, CFStringRef applicationID );

    Parameters

    key

    The preference key whose value to obtain.

    applicationID

    The identifier of the application whose preferences to search, typically kCFPreferencesCurrentApplication. Do not pass NULL or kCFPreferencesAnyApplication. Takes the form of a Java package name, com.foosoft.

    Return Value

    The preference data for the specified key and application. If no value was located, returns NULL. Ownership follows the Create Rule.

    Discussion

    Note that values returned from this function are immutable, even if you have recently set the value using a mutable object.

    Import Statement

    Objective-C

    @import CoreFoundation;

    Swift

    import CoreFoundation

    Availability

    Available in iOS 2.0 and later.

  • Constructs and returns the list of all keys set in the specified domain.

    Declaration

    Swift

    func CFPreferencesCopyKeyList(_ applicationID: CFString!, _ userName: CFString!, _ hostName: CFString!) -> CFArray!

    Objective-C

    CFArrayRef CFPreferencesCopyKeyList ( CFStringRef applicationID, CFStringRef userName, CFStringRef hostName );

    Parameters

    applicationID

    The ID of the application whose preferences to search. Takes the form of a Java package name, com.foosoft.

    userName

    kCFPreferencesCurrentUser to search the current-user domain, otherwise kCFPreferencesAnyUser to search the any-user domain.

    hostName

    kCFPreferencesCurrentHost to search the current-host domain, otherwise kCFPreferencesAnyHost to search the any-host domain.

    Return Value

    The list of keys. Ownership follows the Create Rule.

    Import Statement

    Objective-C

    @import CoreFoundation;

    Swift

    import CoreFoundation

    Availability

    Available in iOS 2.0 and later.

  • Returns a dictionary containing preference values for multiple keys.

    Declaration

    Swift

    func CFPreferencesCopyMultiple(_ keysToFetch: CFArray!, _ applicationID: CFString!, _ userName: CFString!, _ hostName: CFString!) -> CFDictionary!

    Objective-C

    CFDictionaryRef CFPreferencesCopyMultiple ( CFArrayRef keysToFetch, CFStringRef applicationID, CFStringRef userName, CFStringRef hostName );

    Parameters

    keysToFetch

    An array of preference keys the values of which to obtain.

    applicationID

    The ID of the application whose preferences are searched. Takes the form of a Java package name, such as com.foosoft.

    userName

    kCFPreferencesCurrentUser to search the current-user domain, otherwise kCFPreferencesAnyUser to search the any-user domain.

    hostName

    kCFPreferencesCurrentHost to search the current-host domain, otherwise kCFPreferencesAnyHost to search the any-host domain.

    Return Value

    A dictionary containing the preference values for the keys specified by keysToFetch for the specified domain. If no values were located, returns an empty dictionary. Ownership follows the Create Rule.

    Discussion

    Note that values returned from this function are immutable, even if you have recently set the value using a mutable object.

    Import Statement

    Objective-C

    @import CoreFoundation;

    Swift

    import CoreFoundation

    Availability

    Available in iOS 2.0 and later.

  • Returns a preference value for a given domain.

    Declaration

    Swift

    func CFPreferencesCopyValue(_ key: CFString!, _ applicationID: CFString!, _ userName: CFString!, _ hostName: CFString!) -> CFPropertyList!

    Objective-C

    CFPropertyListRef CFPreferencesCopyValue ( CFStringRef key, CFStringRef applicationID, CFStringRef userName, CFStringRef hostName );

    Parameters

    key

    Preferences key for the value to obtain.

    applicationID

    The ID of the application whose preferences are searched. Takes the form of a Java package name, such as com.foosoft.

    userName

    kCFPreferencesCurrentUser if to search the current-user domain, otherwise kCFPreferencesAnyUser to search the any-user domain.

    hostName

    kCFPreferencesCurrentHost if to search the current-host domain, otherwise kCFPreferencesAnyHost to search the any-host domain.

    Return Value

    The preference data for the specified domain. If the no value was located, returns NULL. Ownership follows the Create Rule.

    Discussion

    This function is the primitive get mechanism for the higher level preference function CFPreferencesCopyAppValue Unlike the high-level function, CFPreferencesCopyValue searches only the exact domain specified. Do not use this function directly unless you have a need. All arguments must be non-NULL. Do not use arbitrary user and host names, instead pass the pre-defined domain qualifier constants.

    Note that values returned from this function are immutable, even if you have recently set the value using a mutable object.

    Import Statement

    Objective-C

    @import CoreFoundation;

    Swift

    import CoreFoundation

    Availability

    Available in iOS 2.0 and later.

  • Convenience function that directly obtains a boolean preference value for the specified key.

    Declaration

    Swift

    func CFPreferencesGetAppBooleanValue(_ key: CFString!, _ applicationID: CFString!, _ keyExistsAndHasValidFormat: UnsafeMutablePointer<Boolean>) -> Boolean

    Objective-C

    Boolean CFPreferencesGetAppBooleanValue ( CFStringRef key, CFStringRef applicationID, Boolean *keyExistsAndHasValidFormat );

    Parameters

    key

    The preference key whose value to obtain. The key must specify a preference whose value is of type Boolean.

    applicationID

    The identifier of the application whose preferences are searched, typically kCFPreferencesCurrentApplication. Do not pass NULL or kCFPreferencesAnyApplication. Takes the form of a Java package name, such as com.foosoft.

    keyExistsAndHasValidFormat

    On return, true if the preference value for the specified key was located and found to be of type Boolean, otherwise false.

    Return Value

    The preference data for the specified key and application, or if no value was located, false.

    Import Statement

    Objective-C

    @import CoreFoundation;

    Swift

    import CoreFoundation

    Availability

    Available in iOS 2.0 and later.

  • Convenience function that directly obtains an integer preference value for the specified key.

    Declaration

    Swift

    func CFPreferencesGetAppIntegerValue(_ key: CFString!, _ applicationID: CFString!, _ keyExistsAndHasValidFormat: UnsafeMutablePointer<Boolean>) -> CFIndex

    Objective-C

    CFIndex CFPreferencesGetAppIntegerValue ( CFStringRef key, CFStringRef applicationID, Boolean *keyExistsAndHasValidFormat );

    Parameters

    key

    The preference key whose value you wish to obtain. The key must specify a preference whose value is of type int.

    applicationID

    The identifier of the application whose preferences you wish to search, typically kCFPreferencesCurrentApplication. Do not pass NULL or kCFPreferencesAnyApplication. Takes the form of a Java package name, com.foosoft.

    keyExistsAndHasValidFormat

    On return, indicates whether the preference value for the specified key was located and found to be of type int.

    Return Value

    The preference data for the specified key and application. If no value was located, 0 is returned.

    Import Statement

    Objective-C

    @import CoreFoundation;

    Swift

    import CoreFoundation

    Availability

    Available in iOS 2.0 and later.

  • Adds, modifies, or removes a preference.

    Declaration

    Swift

    func CFPreferencesSetAppValue(_ key: CFString!, _ value: CFPropertyList!, _ applicationID: CFString!)

    Objective-C

    void CFPreferencesSetAppValue ( CFStringRef key, CFPropertyListRef value, CFStringRef applicationID );

    Parameters

    key

    The preference key whose value you wish to set.

    value

    The value to set for the specified key and application. Pass NULL to remove the specified key from the application’s preferences.

    applicationID

    The ID of the application whose preferences you wish to create or modify, typically kCFPreferencesCurrentApplication. Do not pass NULL or kCFPreferencesAnyApplication. Takes the form of a Java package name, com.foosoft.

    Discussion

    New preference values are stored in the standard application preference location, ~/Library/Preferences/. When called with kCFPreferencesCurrentApplication, modifications are performed in the preference domain “Current User, Current Application, Any Host.” If you need to create preferences in some other domain, use the low-level function CFPreferencesSetValue.

    You must call the CFPreferencesAppSynchronize function in order for your changes to be saved to permanent storage.

    Import Statement

    Objective-C

    @import CoreFoundation;

    Swift

    import CoreFoundation

    Availability

    Available in iOS 2.0 and later.

  • Convenience function that allows you to set and remove multiple preference values.

    Declaration

    Swift

    func CFPreferencesSetMultiple(_ keysToSet: CFDictionary!, _ keysToRemove: CFArray!, _ applicationID: CFString!, _ userName: CFString!, _ hostName: CFString!)

    Objective-C

    void CFPreferencesSetMultiple ( CFDictionaryRef keysToSet, CFArrayRef keysToRemove, CFStringRef applicationID, CFStringRef userName, CFStringRef hostName );

    Parameters

    keysToSet

    A dictionary containing the key/value pairs for the preferences to set.

    keysToRemove

    An array containing a list of keys to remove.

    applicationID

    The ID of the application whose preferences you wish to modify. Takes the form of a Java package name, com.foosoft.

    userName

    kCFPreferencesCurrentUser to modify the current user’s preferences, otherwise kCFPreferencesAnyUser to modify the preferences of all users.

    hostName

    kCFPreferencesCurrentHost to modify the preferences of the current host, otherwise kCFPreferencesAnyHost to modify the preferences of all hosts.

    Discussion

    Behavior is undefined if a key is in both keysToSet and keysToRemove

    Import Statement

    Objective-C

    @import CoreFoundation;

    Swift

    import CoreFoundation

    Availability

    Available in iOS 2.0 and later.

  • Adds, modifies, or removes a preference value for the specified domain.

    Declaration

    Swift

    func CFPreferencesSetValue(_ key: CFString!, _ value: CFPropertyList!, _ applicationID: CFString!, _ userName: CFString!, _ hostName: CFString!)

    Objective-C

    void CFPreferencesSetValue ( CFStringRef key, CFPropertyListRef value, CFStringRef applicationID, CFStringRef userName, CFStringRef hostName );

    Parameters

    key

    Preferences key for the value you wish to set.

    value

    The value to set for key and application. Pass NULL to remove key from the domain.

    applicationID

    The ID of the application whose preferences you wish to modify. Takes the form of a Java package name, com.foosoft.

    userName

    kCFPreferencesCurrentUser to modify the current user’s preferences, otherwise kCFPreferencesAnyUser to modify the preferences of all users.

    hostName

    kCFPreferencesCurrentHost to modify the preferences of the current host, otherwise kCFPreferencesAnyHost to modify the preferences of all hosts.

    Discussion

    This function is the primitive set mechanism for the higher level preference function CFPreferencesSetAppValue. Only the exact domain specified is modified. Do not use this function directly unless you have a specific need. All arguments except value must be non-NULL. Do not use arbitrary user and host names, instead pass the pre-defined constants.

    You must call the CFPreferencesSynchronize function in order for your changes to be saved to permanent storage. Note that you can only save preferences for “Any User” if you have root privileges (or Admin privileges prior to OS X v10.6).

    Import Statement

    Objective-C

    @import CoreFoundation;

    Swift

    import CoreFoundation

    Availability

    Available in iOS 2.0 and later.

  • Writes to permanent storage all pending changes to the preference data for the application, and reads the latest preference data from permanent storage.

    Declaration

    Swift

    func CFPreferencesAppSynchronize(_ applicationID: CFString!) -> Boolean

    Objective-C

    Boolean CFPreferencesAppSynchronize ( CFStringRef applicationID );

    Parameters

    applicationID

    The ID of the application whose preferences to write to storage, typically kCFPreferencesCurrentApplication. Do not pass NULL or kCFPreferencesAnyApplication. Takes the form of a Java package name, com.foosoft.

    Return Value

    true if synchronization was successful, otherwise false.

    Discussion

    Calling the function CFPreferencesSetAppValue is not in itself sufficient for storing preferences. The CFPreferencesAppSynchronize function writes to permanent storage all pending preference changes for the application. Typically you would call this function after multiple calls to CFPreferencesSetAppValue. Conversely, preference data is cached after it is first read. Changes made externally are not automatically incorporated. The CFPreferencesAppSynchronize function reads the latest preferences from permanent storage.

    Import Statement

    Objective-C

    @import CoreFoundation;

    Swift

    import CoreFoundation

    Availability

    Available in iOS 2.0 and later.

  • For the specified domain, writes all pending changes to preference data to permanent storage, and reads latest preference data from permanent storage.

    Declaration

    Swift

    func CFPreferencesSynchronize(_ applicationID: CFString!, _ userName: CFString!, _ hostName: CFString!) -> Boolean

    Objective-C

    Boolean CFPreferencesSynchronize ( CFStringRef applicationID, CFStringRef userName, CFStringRef hostName );

    Parameters

    applicationID

    The ID of the application whose preferences you wish to modify. Takes the form of a Java package name, com.foosoft.

    userName

    kCFPreferencesCurrentUser to modify the current user’s preferences, otherwise kCFPreferencesAnyUser to modify the preferences of all users.

    hostName

    kCFPreferencesCurrentHost to search the current-host domain, otherwise kCFPreferencesAnyHost to search the any-host domain.

    Return Value

    true if synchronization was successful, false if an error occurred.

    Discussion

    This function is the primitive synchronize mechanism for the higher level preference function CFPreferencesAppSynchronize; it writes updated preferences to permanent storage, and reads the latest preferences from permanent storage. Only the exact domain specified is modified. Note that to modify “Any User” preferences requires root privileges (or Admin privileges prior to OS X v10.6)—see Authorization Services Programming Guide.

    Do not use this function directly unless you have a specific need. All arguments must be non- NULL. Do not use arbitrary user and host names, instead pass the pre-defined constants.

    Import Statement

    Objective-C

    @import CoreFoundation;

    Swift

    import CoreFoundation

    Availability

    Available in iOS 2.0 and later.

  • Adds suite preferences to an application’s preference search chain.

    Declaration

    Swift

    func CFPreferencesAddSuitePreferencesToApp(_ applicationID: CFString!, _ suiteID: CFString!)

    Objective-C

    void CFPreferencesAddSuitePreferencesToApp ( CFStringRef applicationID, CFStringRef suiteID );

    Parameters

    applicationID

    The ID of the application to which to add suite preferences, typically kCFPreferencesCurrentApplication. Do not pass NULL or kCFPreferencesAnyApplication. Takes the form of a Java package name, com.foosoft.

    suiteID

    The ID of the application suite preferences to add. Takes the form of a Java package name, com.foosoft.

    Discussion

    Suite preferences allow you to maintain a set of preferences that are common to all applications in the suite. When a suite is added to an application’s search chain, all of the domains pertaining to that suite are inserted into the chain. Suite preferences are added between the “Current Application” domains and the “Any Application” domains. If you add multiple suite preferences to one application, the order of the suites in the search chain is non-deterministic. You can override a suite preference for a given application by defining the same preference key in the application specific preferences.

    Import Statement

    Objective-C

    @import CoreFoundation;

    Swift

    import CoreFoundation

    Availability

    Available in iOS 2.0 and later.

  • Removes suite preferences from an application’s search chain.

    Declaration

    Swift

    func CFPreferencesRemoveSuitePreferencesFromApp(_ applicationID: CFString!, _ suiteID: CFString!)

    Objective-C

    void CFPreferencesRemoveSuitePreferencesFromApp ( CFStringRef applicationID, CFStringRef suiteID );

    Parameters

    applicationID

    The ID of the application from which to remove suite preferences, typically kCFPreferencesCurrentApplication. Do not pass NULL or kCFPreferencesAnyApplication. Takes the form of a Java package name, com.foosoft.

    suiteID

    The ID of the application suite preferences to remove. Takes the form of a Java package name, com.foosoft.

    Import Statement

    Objective-C

    @import CoreFoundation;

    Swift

    import CoreFoundation

    Availability

    Available in iOS 2.0 and later.

  • Determines whether or not a given key has been imposed on the user.

    Declaration

    Swift

    func CFPreferencesAppValueIsForced(_ key: CFString!, _ applicationID: CFString!) -> Boolean

    Objective-C

    Boolean CFPreferencesAppValueIsForced ( CFStringRef key, CFStringRef applicationID );

    Parameters

    key

    The key you are querying.

    applicationID

    The application’s ID, typically kCFPreferencesCurrentApplication. Do not pass NULL or kCFPreferencesAnyApplication. Takes the form of a Java package name, com.foosoft.

    Return Value

    true if value of the key cannot be changed by the user, otherwise false.

    Discussion

    In cases where machines and/or users are under some kind of management, you should use this function to determine whether or not to disable UI elements corresponding to those preference keys.

    Import Statement

    Objective-C

    @import CoreFoundation;

    Swift

    import CoreFoundation

    Availability

    Available in iOS 2.0 and later.

  • Constructs and returns the list of all applications that have preferences in the scope of the specified user and host.

    Declaration

    Objective-C

    CFArrayRef CFPreferencesCopyApplicationList ( CFStringRef userName, CFStringRef hostName );

    Parameters

    userName

    kCFPreferencesCurrentUser to search the current-user domain, otherwise kCFPreferencesAnyUser to search the any-user domain.

    hostName

    kCFPreferencesCurrentHost to search the current-host domain, otherwise kCFPreferencesAnyHost to search the any-host domain.

    Return Value

    The list of application IDs. Ownership follows the Create Rule.

    Import Statement

    Objective-C

    @import CoreFoundation;

    Availability

    Available in iOS 2.0 and later.

    Deprecated in iOS 7.0.

Constants

Identifying Preference Domains

  • Keys used to specify the common preference domains.

    Declaration

    Swift

    let kCFPreferencesAnyApplication: CFString! let kCFPreferencesAnyHost: CFString! let kCFPreferencesAnyUser: CFString! let kCFPreferencesCurrentApplication: CFString! let kCFPreferencesCurrentHost: CFString! let kCFPreferencesCurrentUser: CFString!

    Objective-C

    const CFStringRef kCFPreferencesAnyApplication; const CFStringRef kCFPreferencesAnyHost; const CFStringRef kCFPreferencesAnyUser; const CFStringRef kCFPreferencesCurrentApplication; const CFStringRef kCFPreferencesCurrentHost; const CFStringRef kCFPreferencesCurrentUser;

    Constants

    • kCFPreferencesAnyApplication

      kCFPreferencesAnyApplication

      Indicates a preference that applies to any application.

      Available in iOS 2.0 and later.

    • kCFPreferencesAnyHost

      kCFPreferencesAnyHost

      Indicates a preference that applies to any host.

      This option is not supported.

      Available in iOS 2.0 and later.

    • kCFPreferencesAnyUser

      kCFPreferencesAnyUser

      Indicates a preference that applies to any user.

      Available in iOS 2.0 and later.

    • kCFPreferencesCurrentApplication

      kCFPreferencesCurrentApplication

      Indicates a preference that applies only to the current application.

      Available in iOS 2.0 and later.

    • kCFPreferencesCurrentHost

      kCFPreferencesCurrentHost

      Indicates a preference that applies only to the current host.

      Available in iOS 2.0 and later.

    • kCFPreferencesCurrentUser

      kCFPreferencesCurrentUser

      Indicates a preference that applies only to the current user.

      Available in iOS 2.0 and later.

    Discussion

    Not all combinations of application, host, and user are supported preference domains. Specifically, kCFPreferencesAnyHost is not supported in any combination with other options.