Saving and Restoring Property Lists

#include <CoreFoundation/CoreFoundation.h>

#define kNumKids 2

#define kNumBytesInPic 10

CFDictionaryRef CreateMyDictionary( void );

CFPropertyListRef CreateMyPropertyListFromFile( CFURLRef fileURL );

void WriteMyPropertyListToFile( CFPropertyListRef propertyList,

            CFURLRef fileURL );

int main () {

   CFPropertyListRef propertyList;

   CFURLRef fileURL;

   // Construct a complex dictionary object;

   propertyList = CreateMyDictionary();

   // Create a URL that specifies the file we will create to

   // hold the XML data.

   fileURL = CFURLCreateWithFileSystemPath( kCFAllocatorDefault,

               CFSTR("test.txt"),       // file path name

               kCFURLPOSIXPathStyle,    // interpret as POSIX path

               false );                 // is it a directory?

   // Write the property list to the file.

   WriteMyPropertyListToFile( propertyList, fileURL );

   CFRelease(propertyList);

   // Recreate the property list from the file.

   propertyList = CreateMyPropertyListFromFile( fileURL );

   // Release any objects to which we have references.

   CFRelease(propertyList);

   CFRelease(fileURL);

   return 0;

}

CFDictionaryRef CreateMyDictionary( void ) {

   CFMutableDictionaryRef dict;

   CFNumberRef            num;

   CFArrayRef             array;

   CFDataRef              data;

   int                    yearOfBirth;

   CFStringRef            kidsNames[kNumKids];

   // Fake data to stand in for a picture of John Doe.

   const unsigned char pic[kNumBytesInPic] = {0x3c, 0x42, 0x81,

            0xa5, 0x81, 0xa5, 0x99, 0x81, 0x42, 0x3c};

   // Define some data.

   kidsNames[0] = CFSTR("John");

   kidsNames[1] = CFSTR("Kyra");

   yearOfBirth = 1965;

   // Create a dictionary that will hold the data.

   dict = CFDictionaryCreateMutable( kCFAllocatorDefault,

            0,

            &kCFTypeDictionaryKeyCallBacks,

            &kCFTypeDictionaryValueCallBacks );

   // Put the various items into the dictionary.

   // Because the values are retained as they are placed into the

   //  dictionary, we can release any allocated objects here.

   CFDictionarySetValue( dict, CFSTR("Name"), CFSTR("John Doe") );

   CFDictionarySetValue( dict,

            CFSTR("City of Birth"),

            CFSTR("Springfield") );

   num = CFNumberCreate( kCFAllocatorDefault,

            kCFNumberIntType,

            &yearOfBirth );

   CFDictionarySetValue( dict, CFSTR("Year Of Birth"), num );

   CFRelease( num );

   array = CFArrayCreate( kCFAllocatorDefault,

               (const void **)kidsNames,

               kNumKids,

               &kCFTypeArrayCallBacks );

   CFDictionarySetValue( dict, CFSTR("Kids Names"), array );

   CFRelease( array );

   array = CFArrayCreate( kCFAllocatorDefault,

               NULL,

               0,

               &kCFTypeArrayCallBacks );

   CFDictionarySetValue( dict, CFSTR("Pets Names"), array );

   CFRelease( array );

   data = CFDataCreate( kCFAllocatorDefault, pic, kNumBytesInPic );

   CFDictionarySetValue( dict, CFSTR("Picture"), data );

   CFRelease( data );

   return dict;

}

void WriteMyPropertyListToFile( CFPropertyListRef propertyList,

            CFURLRef fileURL ) {

   CFDataRef xmlData;

   Boolean status;

   SInt32 errorCode;

   // Convert the property list into XML data.

   xmlData = CFPropertyListCreateXMLData( kCFAllocatorDefault, propertyList );

   // Write the XML data to the file.

   status = CFURLWriteDataAndPropertiesToResource (

               fileURL,                  // URL to use

               xmlData,                  // data to write

               NULL,

               &errorCode);

   CFRelease(xmlData);

}

CFPropertyListRef CreateMyPropertyListFromFile( CFURLRef fileURL ) {

   CFPropertyListRef propertyList;

   CFStringRef       errorString;

   CFDataRef         resourceData;

   Boolean           status;

   SInt32            errorCode;

   // Read the XML file.

   status = CFURLCreateDataAndPropertiesFromResource(

               kCFAllocatorDefault,

               fileURL,

               &resourceData,            // place to put file data

               NULL,

               NULL,

               &errorCode);

   // Reconstitute the dictionary using the XML data.

   propertyList = CFPropertyListCreateFromXMLData( kCFAllocatorDefault,

               resourceData,

               kCFPropertyListImmutable,

               &errorString);

   CFRelease( resourceData );

   return propertyList;

}

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN"

        "http://www.apple.com/DTDs/PropertyList-1.0.dtd">

<plist version="1.0">

<dict>

    <key>Year Of Birth</key>

    <integer>1965</integer>

    <key>Pets Names</key>

    <array/>

    <key>Picture</key>

    <data>

        PEKBpYGlmYFCPA==

    </data>

    <key>City of Birth</key>

    <string>Springfield</string>

    <key>Name</key>

    <string>John Doe</string>

    <key>Kids Names</key>

    <array>

        <string>John</string>

        <string>Kyra</string>

    </array>

</dict>

</plist>