CoreData教学完整版（封装我们自己的CoreData工具）_Dylan

1. 今天的课程、 大家在学习之后肯定会有另一番想法、

至少、 你们会收藏我的博客吧、嘿嘿、 新开的人气可不怎么高

2. 好、 废话不多说、 直接切入正题、 网上讲coreData的有好多、 但大多数不怎么细致、 也不会完整的敲代码、

所以、 今天上午我自己简单的封装一下coreData供自己使用。 大家可以借鉴一下。 又不足之处还望指出。

3. 开始编码：

　　1. 导入 coreData.FrameWork   我们今天封装的东西、 不实用系统自带的coreData、 而是导入库自己去写。 加深印象

　　思想： 单例 + 中间层 （中间层继承于NSManagedObject 方便我们操作、 也有住于在业务量大的时候优化代码）

　　总共4个文件 我们开始编码：

　　1、单例 ADCoreData.h

　　

//
//  ADCoreData.h
//  CoreData_CE
//
//  Created by Dylan on 14-10-11.
//  Copyright (c) 2014年 Dylan. All rights reserved.
//

/*!
 *  @Author Dylan.
 *
 *  Please add CoreData.FrameWork
 */

#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>

@interface ADCoreData : NSObject

/*!
 *  @Author Dylan.
 *
 *  context
 */
@property (nonatomic, strong, readonly) NSManagedObjectContext * manageContext;

+ (instancetype)shareInstanceWithStoreName: (NSString *)storeName;

/*!
 *  @Author Dylan.
 *
 *  Methods
 */

- (NSMutableArray *)findByModel: (id)model;
- (NSMutableArray *)findByModel: (id)model
                   predicateString: (NSString *)predicateString;
/*!
 *  Update
 */
- (BOOL)create: (id)model;

- (BOOL)remove: (id)model;
- (BOOL)remove: (id)model
      predicateString: (NSString *)predicateString;
- (BOOL)modify: (id)model
 predicateString: (NSString *)predicateString;

@end

　　ADCoreData.m

//
//  ADCoreData.m
//  CoreData_CE
//
//  Created by Dylan on 14-10-11.
//  Copyright (c) 2014年 Dylan. All rights reserved.
//

#import "ADCoreData.h"
#import "ADCoreDataManager.h"
#import <objc/runtime.h>

#define CLASS_NAME(PRAM) NSStringFromClass([PRAM class])

@interface ADCoreData ()

@property (nonatomic, strong) NSManagedObjectModel * managedobjectModel;
@property (nonatomic, strong) NSPersistentStoreCoordinator * persistentStoreCoordinator;

/*!
 *  @Author Dylan.
 *
 *  storeName
 */
@property (nonatomic, strong) NSString * storeName;

- (NSURL *)applicationDomainUrl;

@end

static ADCoreData * coreData;

@implementation ADCoreData

+ (instancetype)shareInstanceWithStoreName:(NSString *)storeName {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        coreData = [[self alloc] init];
        coreData.storeName = storeName;
    });
    
    return coreData;
}

/*!
 *  @Author Dylan.
 *
 *  synthesize
 */
@synthesize manageContext = _manageContext;
@synthesize managedobjectModel = _managedobjectModel;
@synthesize persistentStoreCoordinator = _persistentStoreCoordinator;

#pragma mark -
#pragma mark - GET
- (NSManagedObjectContext *)manageContext {
    
    if (_manageContext) {
        return _manageContext;
    }
    
    NSPersistentStoreCoordinator * coordinator = [self persistentStoreCoordinator];
    if (coordinator != nil) {
        _manageContext = [[NSManagedObjectContext alloc] init];
        [_manageContext setPersistentStoreCoordinator:coordinator];
    }
    return _manageContext;
}

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
    
    if (_persistentStoreCoordinator) {
        return _persistentStoreCoordinator;
    }
    
    NSURL * storeUrl = [[self applicationDomainUrl] URLByAppendingPathComponent:[NSString stringWithFormat:@"%@.sqlite", _storeName]];
    _persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:self.managedobjectModel];
    [_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:nil error:nil];
    return _persistentStoreCoordinator;
}

- (NSManagedObjectModel *)managedobjectModel {
    
    if (_managedobjectModel) {
        return _managedobjectModel;
    }
    
    NSURL * modelUrl = [[NSBundle mainBundle] URLForResource:_storeName withExtension:@"momd"];
    _managedobjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelUrl];
    return _managedobjectModel;
}

#pragma mark - Methods
- (NSMutableArray *)findByModel: (id)model {
    
    NSError * error = nil;
    NSArray * listArray = [_manageContext executeFetchRequest:[self bindRequest:CLASS_NAME(model) predicate:nil] error:&error];
    NSMutableArray * resultArray = [NSMutableArray array];
    
    for (ADCoreDataManager * manager in listArray) {
        
        for (NSString * propertyName in [self ClassAttributes:model]) {
            [model setValue:[manager valueForKey:propertyName] forKey:propertyName];
        }
        [resultArray addObject:model];
    }
    return resultArray;
}

- (NSMutableArray *)findByModel: (id)model
                predicateString: (NSString *)predicateString; {
    
    NSError * error = nil;
    NSArray * listArray = [_manageContext executeFetchRequest:[self bindRequest:CLASS_NAME(model) predicate:predicateString] error:&error];
    NSMutableArray * resultArray = [NSMutableArray array];
    
    if (listArray.count >= 1) {
        for (ADCoreDataManager * manager in listArray) {
            
            for (NSString * propertyName in [self ClassAttributes:model]) {
                [model setValue:[manager valueForKey:propertyName] forKey:propertyName];
            }
            [resultArray addObject:model];
        }
    }
    return resultArray;
}

#pragma mark update
- (BOOL)create: (id)model {
    ADCoreDataManager * manager = [NSEntityDescription insertNewObjectForEntityForName:CLASS_NAME(model) inManagedObjectContext:_manageContext];
    
    for (NSString * propertyName in [self ClassAttributes:model]) {
        [manager setValue:[model valueForKey:propertyName] forKey:propertyName];
    }
    BOOL result = [self saveContext];
    return result;
}

- (BOOL)remove: (id)model {
    
    NSError * error = nil;
    NSArray * listArray = [_manageContext executeFetchRequest:[self bindRequest:CLASS_NAME(model) predicate:nil] error:&error];
    if (listArray.count > 0) {
        for (ADCoreDataManager * manager in listArray) {
            [_manageContext deleteObject:manager];
        }
    }
    return [self saveContext];
}

- (BOOL)remove: (id)model
predicateString: (NSString *)predicateString {
    
    NSError * error = nil;
    NSArray * listArray = [_manageContext executeFetchRequest:[self bindRequest:CLASS_NAME(model) predicate:predicateString] error:&error];
    
    if (listArray.count > 0) {
        for (ADCoreDataManager * manager in listArray) {
            [_manageContext deleteObject:manager];
        }
    }
    return [self saveContext];
}

- (BOOL)modify: (id)model
 predicateString: (NSString *)predicateString {
    
    NSError * error = nil;
    NSArray * listArray = [_manageContext executeFetchRequest:[self bindRequest:CLASS_NAME(model) predicate:predicateString] error:&error];
    
    if (listArray.count > 0) {
        
        for (ADCoreDataManager * manager in listArray) {
            for (NSString * propertyName in [self ClassAttributes:model]) {
                [manager setValue:[model valueForKey:propertyName] forKey:propertyName];
            }
        }
    }
    return [self saveContext];
}

#pragma mark - collect
- (NSFetchRequest *)bindRequest: (NSString *)className
          predicate: (NSString *)predicateString {
    NSFetchRequest * request = [[NSFetchRequest alloc] init];
    [request setEntity:[NSEntityDescription entityForName:className inManagedObjectContext:_manageContext]];
    
    if (predicateString != nil) {
        NSPredicate * predicate = [NSPredicate predicateWithFormat:predicateString];
        NSLog(@"%@", predicate);
        NSLog(@"%@", predicateString);
        [request setPredicate:predicate];
    }
    return request;
}


#pragma mark - save
- (BOOL)saveContext {
    
    NSManagedObjectContext * context = [self manageContext];
    if (context != nil) {
        
        NSError * error = nil;
        if ([context hasChanges] && ![context save:&error]) {
            NSLog(@"%@", [error userInfo]);
            abort();
            return NO;
        }
    }
    
    return YES;
}


- (NSURL *)applicationDomainUrl {
    return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
}

#pragma mark - allAttributes
- (NSMutableArray *) ClassAttributes: (id)classModel {
    
    NSMutableArray * array = [NSMutableArray array];
    NSString *className = NSStringFromClass([classModel class]);
    const char * cClassName = [className UTF8String];
    
    id classM = objc_getClass(cClassName);
    unsigned int outCount, i;
    objc_property_t * properties = class_copyPropertyList(classM, &outCount);
    for (i = 0; i < outCount; i++) {
        objc_property_t property = properties[i];
        NSString * attributeName = [NSString stringWithUTF8String:property_getName(property)];
        
        [array addObject:attributeName];
    }
    return array;
}

@end

　　在m文件中， 我使用了运行时。  运行时拿到一个模型的属性 这样我们可以更加方便的使用KVC

　　大家仔细看一下这种封装的过程　　

2.中间层： ADCoreDataManager.h

　　

//
//  ADCoreDataManager.h
//  CoreData_CE
//
//  Created by Dylan on 14-10-11.
//  Copyright (c) 2014年 Dylan. All rights reserved.
//

#warning add Model properties Here

#import <CoreData/CoreData.h>
#import <Foundation/Foundation.h>

@interface ADCoreDataManager : NSManagedObject

/*!
 *  @Author Dylan.
 *
 *  e.g
 */
@property (nonatomic, strong) NSString * name;

@end

　　.m文件

　　

//
//  ADCoreDataManager.m
//  CoreData_CE
//
//  Created by Dylan on 14-10-11.
//  Copyright (c) 2014年 Dylan. All rights reserved.
//

#warning don't forget write @synthesize

#import "ADCoreDataManager.h"

@implementation ADCoreDataManager

@synthesize name = _name;

- (void)setValue:(id)value forUndefinedKey:(NSString *)key {
    
}

@end

　　大家可以把所有模型的属性 扔到中间层里边。  使用中间层去做中介传值。

　　使用：

　　1. 创建自己的momd文件。   新建-》coredata-》model 创建之后添加模型

　　2. 初始化单例

　　附上测试代码

　　

// test
    ADCoreData * coreData = [ADCoreData shareInstanceWithStoreName:@"CoreData"];
    
    Dylan * dylan = [[Dylan alloc] initWithEntity:[NSEntityDescription entityForName:@"Dylan" inManagedObjectContext:coreData.manageContext] insertIntoManagedObjectContext:nil];
    [dylan setName:@"Dylan"];
    
    NSLog(@"**************************************************");
    
    NSLog(@"first = %@", [coreData findByModel:dylan]);
    
    NSLog(@"**************************************************");
    
    [coreData create:dylan];
    NSLog(@"second = %@", [coreData findByModel:dylan]);
    NSLog(@"third = %@", [coreData findByModel:dylan predicateString:@"name = 'Dylan'"]);
    NSLog(@"**************************************************");
    
    [coreData remove:dylan];
    NSLog(@"fourth = %@", [coreData findByModel:dylan]);
    NSLog(@"**************************************************");
    
    [coreData create:dylan];
    NSLog(@"fifth = %@", [coreData findByModel:dylan]);
    
    NSLog(@"**************************************************");
    
    Dylan * dylan1 = [[Dylan alloc] initWithEntity:[NSEntityDescription entityForName:@"Dylan" inManagedObjectContext:coreData.manageContext] insertIntoManagedObjectContext:nil];
    dylan1.name = @"dylan-1";
    
    [coreData modify:dylan1 predicateString:nil];
    NSLog(@"sixth = %@", [coreData findByModel:dylan]);
    NSLog(@"seventh = %@", [coreData findByModel:dylan1]);

　　CoreData书写虽然比较难， 但是操作方便

　　大家在使用谓词的时候 要特别的注意  在你的值上边加单引号 类似： name = 'Dylan' 防止CoreData在操作request请求时候出现错误

　　@Dylan.