保存 PFObject NSCoding [英] Saving PFObject NSCoding

问题描述

我的问题: saveInBackground 不起作用.

它不起作用的原因:我正在使用 NSKeyedArchiving 将存储在 NSArray 中的 PFObjects 保存到文件中.我这样做的方法是通过这个库实现NSCoding.由于某种我不知道的原因，正在添加其他几个字段并设置为 NULL.我有一种感觉，这会破坏对 saveInBackground 的 API 调用.当我在第一组对象上调用 saveInBackground 时(在 NSKeyedArchiving 之前)saveInBackground 工作得很好.但是，当我在第二个对象上调用它时(在 NSKeyedArchiving 之后)它不会保存.这是为什么?

The Reason It's not working: I'm saving PFObjects stored in an NSArray to file using NSKeyedArchiving. The way I do that is by implementing NSCoding via this library. For some reason unknown to me, several other fields are being added and are set to NULL. I have a feeling that this is screwing up the API call to saveInBackground. When I call saveInBackground on the first set of objects (before NSKeyedArchiving) saveInBackground works just fine. However, when I call it on the second object (after NSKeyedArchiving) it does not save. Why is this?

保存

[NSKeyedArchiver archiveRootObject:_myArray toFile:[self returnFilePathForType:@"myArray"]];

检索

_myArray = (NSMutableArray *)[NSKeyedUnarchiver unarchiveObjectWithFile:
                                             [self returnFilePathForType:@"myArray"]];

NSArchiving 之前的对象

2014-04-16 16:34:56.267 myApp[339:60b]
<UserToMessage:bXHfPM8sDs:(null)> {
    from = "<PFUser:sdjfa;lfj>";
    messageText = "<MessageText:asdffafs>";
    read = 0;
    to = "<PFUser:asdfadfd>";
}
2014-04-16 16:34:56.841 myApp[339:60b]
<UserToMessage:bXHsdafdfs:(null)> {
    from = "<PFUser:eIasdffoF3gi>";
    messageText = "<MessageText:asdffafs>";
    read = 1;
    to = "<PFUser:63sdafdf5>";
}

NSArchiving 后的对象

<UserToMessage:92GGasdffVQLa:(null)> {
    ACL = "<null>";
    createdAt = "<null>";
    from = "<PFUser:eIQsadffF3gi>";
    localId = "<null>";
    messageText = "<MessageText:EudsaffdHpc>";
    objectId = "<null>";
    parseClassName = "<null>";
    read = 0;
    saveDelegate = "<null>";
    to = "<PFUser:63spasdfsxNp5>";
    updatedAt = "<null>";
}

2014-04-16 16:37:46.527 myApp[352:60b]
<UserToMessage:92GadfQLa:(null)> {
    ACL = "<null>";
    createdAt = "<null>";
    from = "<PFUser:eIQsadffF3gi>";
    localId = "<null>";
    messageText = "<MessageText:EuTndasHpc>";
    objectId = "<null>";
    parseClassName = "<null>";
    read = 1;
    saveDelegate = "<null>";
    to = "<PFUser:63spPsadffp5>";
    updatedAt = "<null>";
}

使用 Florent 的 PFObject 类别更新:

PFObject+MyPFObject_NSCoding.h

#import <Parse/Parse.h>

@interface PFObject (MyPFObject_NSCoding)

-(void) encodeWithCoder:(NSCoder *) encoder;
-(id) initWithCoder:(NSCoder *) aDecoder;
@end

@interface PFACL (extensions)
-(void) encodeWithCoder:(NSCoder *) encoder;
-(id) initWithCoder:(NSCoder *) aDecoder;
@end


 PFObject+MyPFObject_NSCoding.m

#import "PFObject+MyPFObject_NSCoding.h"
@implementation PFObject (MyPFObject_NSCoding)
#pragma mark - NSCoding compliance
#define kPFObjectAllKeys @"___PFObjectAllKeys"
#define kPFObjectClassName @"___PFObjectClassName"
#define kPFObjectObjectId @"___PFObjectId"
#define kPFACLPermissions @"permissionsById"
-(void) encodeWithCoder:(NSCoder *) encoder{

    // Encode first className, objectId and All Keys
    [encoder encodeObject:[self className] forKey:kPFObjectClassName];
    [encoder encodeObject:[self objectId] forKey:kPFObjectObjectId];
    [encoder encodeObject:[self allKeys] forKey:kPFObjectAllKeys];
    for (NSString * key in [self allKeys]) {
        [encoder  encodeObject:self[key] forKey:key];
    }


}
-(id) initWithCoder:(NSCoder *) aDecoder{

    // Decode the className and objectId
    NSString * aClassName  = [aDecoder decodeObjectForKey:kPFObjectClassName];
    NSString * anObjectId = [aDecoder decodeObjectForKey:kPFObjectObjectId];


    // Init the object
    self = [PFObject objectWithoutDataWithClassName:aClassName objectId:anObjectId];

    if (self) {
        NSArray * allKeys = [aDecoder decodeObjectForKey:kPFObjectAllKeys];
        for (NSString * key in allKeys) {
            id obj = [aDecoder decodeObjectForKey:key];
            if (obj) {
                self[key] = obj;
            }

        }
    }
    return self;
}
@end

推荐答案

我创建了一个非常简单的解决方法，无需更改上述 NSCoding 库:

I have created a very simple workaround that requires no change the above NSCoding Libraries:

PFObject *tempRelationship = [PFObject objectWithoutDataWithClassName:@"relationship" objectId:messageRelationship.objectId];
        [tempRelationship setObject:[NSNumber numberWithBool:YES] forKey:@"read"];
        [tempRelationship saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
            if (succeeded)
                NSLog(@"Success");
            else
                NSLog(@"Error");
        }];

我们在这里做的是创建一个具有相同 objectId 的临时对象，并保存它.这是一个有效的解决方案，不会在服务器上创建对象的副本.感谢所有提供帮助的人.

What we're doing here is creating a temporary object with the same objectId, and saving it. This is a working solution that does not create a duplicate of the object on the server. Thanks to everyone who has helped out.

这篇关于保存 PFObject NSCoding的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！