Mac Preferences Read and Write

This article applies to macOS only.

See also: Multiplatform Programming Guide

│ English (en) │

macOS File Storage Overview

Before we go any further, let's recap where the Apple Guidelines indicate your application should store its files:

• Use the /Applications or /Applications/Utilities directory for the application bundle. The application bundle should contain everything: libraries, dependencies, help, every file that the application needs to run except those created by the application itself. If the application bundle is copied to another machine's /Applications or /Applications/Utilities directory, it should be able to run. Installing to these folders requires Admin privileges. The data in these folders is backed up by Time Machine.

• Use the ~/Applications directory should Admin privileges not be available. This is the standard location for a single user application. This directory should not be expected to exist. The application bundle should contain everything: libraries, dependencies, help, every file that the application needs to run except those created by the application itself. If the application bundle is copied to another machine's /Applications or /Applications/Utilities directory, it should be able to run. This data is backed up by Time Machine.

• Use the Application Support directory (this data is backed up by Time Machine), appending your <bundle_ID>, for:
  • Resource and data files that your application creates and manages for the user. You might use this directory to store application state information, computed or downloaded data, or even user created data that you manage on behalf of the user.
  • Autosave files.

• Use the Caches directory (this is not backed up by Time Machine), appending your <bundle_ID>, for cached data files or any files that your application can recreate easily.

• Use CFPreferences to read and write your application's preferences. This will automatically write preferences to the appropriate location and read them from the appropriate location. This data is backed up by Time Machine.

• Use the application Resources directory (this is backed up by Time Machine) for your application-supplied image files, sound files, icon files and other unchanging data files necessary for your application's operation.

• Use NSTemporaryDirectory (this is not backed up by Time Machine) to store temporary files that you intend to use immediately for some ongoing operation but then plan to discard later. Delete temporary files as soon as you are done with them.

Preferences

For those who want to read and write preferences for a macOS application, this can be done using the following methods:

CODE FOR READING PREFERENCES

  uses MacOSAll, CFPreferences;

  var
    IsValid: Boolean;  // On return indicates if key exists and has valid data
    Pref: Integer;

  procedure TForm1.FormCreate(Sender: TObject);
  begin
    try
       Pref := CFPreferencesGetAppIntegerValue(CFStr('Check1'),kCFPreferencesCurrentApplication,IsValid);
       if (Pref = 1) then
          CheckBox1.Checked := true
       else
          CheckBox1.Checked := false;

       Pref := CFPreferencesGetAppIntegerValue(CFStr('Check2'),kCFPreferencesCurrentApplication,IsValid);
       if (Pref = 1) then
          CheckBox2.Checked := true
       else
          CheckBox2.Checked := false;

       Pref := CFPreferencesGetAppIntegerValue(CFStr('Check3'),kCFPreferencesCurrentApplication,IsValid);
       if (Pref = 1) then
          CheckBox3.Checked := true
       else
          CheckBox3.Checked := false;

       Pref := CFPreferencesGetAppIntegerValue(CFStr('Check4'),kCFPreferencesCurrentApplication,IsValid);
       if (Pref = 1) then
          CheckBox4.Checked := true
       else
          CheckBox4.Checked := false;

    except
      on E : Exception do
        ShowMessage(E.ClassName+' error raised, with message : '+E.Message);
    end;
  end;

CODE FOR WRITING PREFERENCES

  uses MacOSAll, CFPreferences;

  var
    ItemName: CFStringRef;
    ItemVal: CFPropertyListRef;

  procedure TForm1.FormClose(Sender: TObject);
  begin
    try
       if (CheckBox1.Checked) then
         begin
           ItemName := CFStr('Check1');
           ItemVal := CFStringCreateWithPascalString(kCFAllocatorDefault,'1',kCFStringEncodingUTF8);
           CFPreferencesSetAppValue(ItemName,ItemVal,kCFPreferencesCurrentApplication);
         end
       else
         begin
           ItemName := CFStr('Check1');
           ItemVal := CFStringCreateWithPascalString(kCFAllocatorDefault,'0',kCFStringEncodingUTF8);
           CFPreferencesSetAppValue(ItemName,ItemVal,kCFPreferencesCurrentApplication);
         end;

       if (CheckBox2.Checked) then
         begin
           ItemName := CFStr('Check2');
           ItemVal := CFStringCreateWithPascalString(kCFAllocatorDefault,'1',kCFStringEncodingUTF8);
           CFPreferencesSetAppValue(ItemName,ItemVal,kCFPreferencesCurrentApplication);
         end
       else 
         begin
           ItemName := CFStr('Check2');
           ItemVal := CFStringCreateWithPascalString(kCFAllocatorDefault,'0',kCFStringEncodingUTF8);
           CFPreferencesSetAppValue(ItemName,ItemVal,kCFPreferencesCurrentApplication);
         end;
       
       if (CheckBox3.Checked) then
         begin
           ItemName := CFStr('Check3');
           ItemVal := CFStringCreateWithPascalString(kCFAllocatorDefault,'1',kCFStringEncodingUTF8);
           CFPreferencesSetAppValue(ItemName,ItemVal,kCFPreferencesCurrentApplication);
         end
       else
         begin
           ItemName := CFStr('Check3');
           ItemVal := CFStringCreateWithPascalString(kCFAllocatorDefault,'0',kCFStringEncodingUTF8);
           CFPreferencesSetAppValue(ItemName,ItemVal,kCFPreferencesCurrentApplication);
         end;

       if (CheckBox4.Checked) then
         begin
           ItemName := CFStr('Check4');
           ItemVal := CFStringCreateWithPascalString(kCFAllocatorDefault,'1',kCFStringEncodingUTF8);
           CFPreferencesSetAppValue(ItemName,ItemVal,kCFPreferencesCurrentApplication);
         end
       else
         begin
           ItemName := CFStr('Check4');
           ItemVal := CFStringCreateWithPascalString(kCFAllocatorDefault,'0',kCFStringEncodingUTF8);
           CFPreferencesSetAppValue(ItemName,ItemVal,kCFPreferencesCurrentApplication);
         end;

       CFPreferencesAppSynchronize(kCFPreferencesCurrentApplication);

     except
       on E : Exception do
         ShowMessage(E.ClassName+' error raised, with message : '+E.Message);
     end;

See also

• Introduction to platform-sensitive development
• Proper macOS file locations
• macOS Programming Tips

External links

• Apple: Managing Preferences Using Core Foundation
• Apple: Preferences
• Apple: Preference Utilities
• Apple: About Preferences and Settings
• Apple: Human Interface Guidelines -Preferences