libs-base/Tools/NSPropertyList+PLUtil.m

/** Permit handling JSON as plists, and writing Objective-C literals.
   Copyright (C) 2020 Free Software Foundation, Inc.

   Written by:  Mingye Wang
   Created: feb 2020

   This file is part of the GNUstep Objective-C Library.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free
   Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02111 USA.

*/
#import "NSPropertyList+PLUtil.h"
#import "GNUstepBase/GSObjCRuntime.h"
#import "Foundation/NSData.h"
#import "Foundation/NSUserDefaults.h"
#import "Foundation/NSJSONSerialization.h"

static IMP originalRead = 0;
static IMP originalWrite = 0;

@implementation NSPropertyListSerialization (PLUtilAdditions)
+ (NSData *)_pdataFromPropertyList:(id)aPropertyList
			    format:(NSPropertyListFormat)aFormat
		  errorDescription:(NSString **)anErrorString
{
  NSError *     myError = nil;
  NSData *      dest;
  NSDictionary *loc;
  loc = [[NSUserDefaults standardUserDefaults] dictionaryRepresentation];
  switch (aFormat)
    {
    case NSPropertyListJSONFormat:
      dest = [NSJSONSerialization
	dataWithJSONObject:aPropertyList
		   options:loc != nil ? NSJSONWritingPrettyPrinted : 0
		     error:&myError];
      if (myError != nil && anErrorString != NULL)
	{
	  *anErrorString = [myError description];
	}
      return dest;
    case NSPropertyListObjectiveCFormat:
    case NSPropertyListSwiftFormat:
      *anErrorString = @"Not implemented";
      return nil;
    default:
      return (*originalWrite)(self, _cmd, aPropertyList, aFormat, anErrorString);
    }
}

+ (id)_ppropertyListWithData:(NSData *)data
		     options:(NSPropertyListReadOptions)anOption
		      format:(NSPropertyListFormat *)aFormat
		       error:(out NSError **)error;
{
  NSError *	    myError = nil;
  NSPropertyListFormat format;
  NSJSONReadingOptions jsonOptions = NSJSONReadingAllowFragments;
  id prop = (*originalRead)(self, _cmd, data, anOption, &format, &myError);
  if (prop == nil)
    if (format == NSPropertyListOpenStepFormat
	|| format == NSPropertyListGNUstepFormat)
      // rescue as json when we know it is not anything else
      {
	switch (anOption)
	  {
	  case NSPropertyListMutableContainersAndLeaves:
	    jsonOptions |= NSJSONReadingMutableLeaves;
	    /* FALLTHROUGH */
	  case NSPropertyListMutableContainers:
	    jsonOptions |= NSJSONReadingMutableContainers;
	  }
	format = NSPropertyListJSONFormat;
	prop = [NSJSONSerialization JSONObjectWithData:data
					       options:jsonOptions
						 error:&myError];
      }
  if (error != NULL)
    *error = myError;
  if (*aFormat != NULL)
    *aFormat = format;
  return prop;
}

+ (void)load
{
  Method replacementRead;
  Method replacementWrite;

  replacementRead
    = class_getClassMethod(self, @selector
			   (_ppropertyListWithData:options:format:error:));
  replacementWrite
    = class_getClassMethod(self, @selector
			   (_pdataFromPropertyList:format:errorDescription:));

  originalRead
    = class_replaceMethod(object_getClass(self),
			  @selector(propertyListWithData:options:format:error:),
			  method_getImplementation(replacementRead),
			  method_getTypeEncoding(replacementRead));
  originalWrite
    = class_replaceMethod(object_getClass(self),
			  @selector(dataFromPropertyList:
						  format:errorDescription:),
			  method_getImplementation(replacementWrite),
			  method_getTypeEncoding(replacementWrite));
}
@end