私は次の目的でアプリを構築することを目指しています:
私のコア データには以下が含まれます。
- リクエスト
- 画像
私のリクエストオブジェクトには、次のものがあります。
#import <Foundation/Foundation.h>
@interface BAPRequest : NSObject
@property (nonatomic, retain) NSString *requestID;
@property (nonatomic, retain) NSString *name;
@property (nonatomic, retain) NSString *email;
@property (nonatomic, retain) NSString *phone;
@property (nonatomic, retain) NSString *detail;
@property (nonatomic, retain) NSMutableArray *images;
@property (nonatomic, retain) NSDate *requestDate;
@property (nonatomic) BOOL isSent;
- (void)fetchImages;
@end
そして .m ファイル:
#import "BAPAppDelegate.h"
#import "BAPRequest.h"
@implementation BAPRequest
@synthesize name, email, phone, detail;
@synthesize images;
@synthesize requestDate;
@synthesize isSent;
@synthesize requestID;
- (id)init{
self = [super init];
if(self != nil){
self.isSent = false;
self.requestID = [[NSProcessInfo processInfo] globallyUniqueString];
self.images = [[NSMutableArray alloc] init];
}
return self;
}
- (void)fetchImages{
//get delegation
BAPAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
NSManagedObjectContext *context = [appDelegate managedObjectContext];
NSError *error;
//init request
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
//load the entity description
NSEntityDescription *entityDescription = [NSEntityDescription entityForName:@"Image"
inManagedObjectContext:context];
//set the request query
[fetchRequest setEntity:entityDescription];
//set predicate to request to ask select specific entity with the matching line num
NSPredicate *pred = [NSPredicate predicateWithFormat:@"(requestId == %@)", self.requestID];
[fetchRequest setPredicate:pred];
//exec the command to find the object(table) from core database
NSArray * imageList = [context executeFetchRequest:fetchRequest error:&error];
for (NSManagedObject *imageObject in imageList){
[self.images addObject: [UIImage imageWithData:[imageObject valueForKey:@"content"]]];
}
}
@end
すべてのリクエストを取得するために、次のことも行います。
- (void)removeRequest:(BAPRequest*)request{
//get delegation
BAPAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
NSManagedObjectContext *context = [appDelegate managedObjectContext];
NSError *error;
//init request
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
//load the entity description
NSEntityDescription *entityDescription = [NSEntityDescription entityForName:@"Request"
inManagedObjectContext:context];
//set the request query
[fetchRequest setEntity:entityDescription];
//set predicate to request to ask select specific entity with the matching line num
NSLog(@"request id is %@", request.requestID);
NSPredicate *pred = [NSPredicate predicateWithFormat:@"(requestId LIKE %@)", request.requestID];
[fetchRequest setPredicate:pred];
//exec the command to find the object(table) from core database
NSArray *objects = [context executeFetchRequest:fetchRequest error:&error];
//if this object doesn't exist in the database, it must be something wrong
if (objects == nil) {
NSLog(@"There was an error !");
NSLog(@"Error Info: %@", error);
}
//if object exist in database, take the first search object, and deletes it
if ([objects count] > 0){
NSManagedObject *theRequest = [objects objectAtIndex:0];
[context deleteObject:theRequest];
}
[context save:&error];
/*
//delete existing images relates to this request first
entityDescription = [NSEntityDescription entityForName:@"Image"
inManagedObjectContext:context];
pred = [NSPredicate predicateWithFormat:@"(self.request == %@)", request];
[fetchRequest setPredicate:pred];
NSArray * imageList = [context executeFetchRequest:fetchRequest error:&error];
for (NSManagedObject *removeImageObject in imageList){
[context deleteObject:removeImageObject];
}
*/
}
#pragma mark - Convert Core Data Object to Request Object
#pragma mark - Core Data Methods
- (NSMutableArray *)getRequests{
//get app delegate
BAPAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
//get object context that's created for us
NSManagedObjectContext *context = [appDelegate managedObjectContext];
//define the entities we want load to description
NSEntityDescription *entityDescription = [NSEntityDescription entityForName:@"Request"
inManagedObjectContext:context];
//init request and set search query to the request
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
[fetchRequest setEntity:entityDescription];
NSError *error;
//get objects(table) though request
NSArray *objects = [context executeFetchRequest:fetchRequest error:&error];
if (objects == nil){
NSLog(@"There was an error !");
//error handling there
NSLog(@"Error Info: %@", error);
}
NSMutableArray *requests = [[NSMutableArray alloc] init];
for (NSManagedObject *requestObj in objects){
BAPRequest *request = [[BAPRequest alloc] init];
request.requestID = [requestObj valueForKey:@"requestId"];
request.name = [requestObj valueForKey:@"name"];
request.email = [requestObj valueForKey:@"email"];
request.phone = [requestObj valueForKey:@"phone"];
request.detail = [requestObj valueForKey:@"detail"];
request.requestDate = [requestObj valueForKey:@"requestDate"];
request.isSent = [[requestObj valueForKey:@"isSent"] boolValue];
[request fetchImages];
[requests addObject: requestObj];
}
return requests; //return the requests
}
- (void)saveRequest:(BAPRequest *)request{
request.requestDate = [NSDate date];
//get delegation
BAPAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
NSManagedObjectContext *context = [appDelegate managedObjectContext];
NSError *error;
BAPRequest *theRequest = [NSEntityDescription insertNewObjectForEntityForName:@"Request"
inManagedObjectContext:context];
//set the request obejct basics
[theRequest setValue:request.requestID forKey:@"requestId"];
[theRequest setValue:request.name forKey:@"name"];
[theRequest setValue:request.email forKey:@"email"];
[theRequest setValue:request.phone forKey:@"phone"];
[theRequest setValue:request.detail forKey:@"detail"];
[theRequest setValue:request.requestDate forKey:@"requestDate"];
[theRequest setValue:[NSNumber numberWithBool:request.isSent ] forKey:@"isSent"];
//also save its requests
for (UIImage *img in request.images) {
//init image object
UIImage *newImage=[NSEntityDescription insertNewObjectForEntityForName:@"Image" inManagedObjectContext:context];
[newImage setValue:request.requestID forKey:@"requestId"];
[newImage setValue:UIImagePNGRepresentation(img) forKey:@"content"];
}
[context save:&error]; //save the object
}
@end
私の問題は次のとおりです。
画像をまったく取得していないと思います。getRequests メソッドで画像をフェッチしても、リクエストを別の場所に渡そうとすると、まだ多くの問題が発生します。
- ブール値が正しくロードされていません
- 画像はゼロです（フェッチ時にロードされた場合でも）
その理由は (私が間違っている可能性があります)、これらの要求オブジェクト (BAPRequest*) を NSArray に格納してテーブル ビューに渡すと、それらを配列 ([myArray objectAtIndex:0] など) からロードすると、まだNSManagedObjectです。コア データ エンティティ オプションでクラス名を指定して、BAPRequest の Request(Core Data) オブジェクト クラスを作成しようとしましたが、NSManagedObject のサブクラス化が不可能な場合、NSManagedObject をサブクラス化する必要があると言い続けています。
私はできません：
BAPRequest: NSManagedObject
XCodeはそれが好きではありません。