iOS KeyMapping

昨天遇到一个需求，大致是这样子的

{
  key = value;
  anotherKey = anotherValue;
}

将上面的 Dictionary 转换成

{
  newKey = value;
  newAnotherKey = anotherValue;
}

也就是值不变，key 变化。那就是一个 KeyMapping 映射

那自然是用一个 Category 来做，参数是 映射字典
上代码

@interface NSDictionary (ZBKeyMapping)
- (NSDictionary *)zbRemapKeyWithMappingDictionary:(NSDictionary *)keyMappingDic removingNullValues:(BOOL)removeNulls;
@end

@implementation NSDictionary (ZBKeyMapping)
- (NSDictionary *)zbRemapKeyWithMappingDictionary:(NSDictionary *)keyMappingDic removingNullValues:(BOOL)removeNulls {
    __block NSMutableDictionary *newDictionary = [NSMutableDictionary dictionaryWithCapacity:[self count]];
    
    [self enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
        if (removeNulls) {
            if ([obj isEqual:[NSNull null]]) {
                return;
            }
        }
        
        id newKey = keyMappingDic[key];
        if (!newKey) {
            [newDictionary setObject:obj forKey:key];
        } else {
            [newDictionary setObject:obj forKey:newKey];
        }
    }];
    return [newDictionary copy];
}
@end

然后是简单的使用

NSDictionary *oringinDic = @{@"key":@"value",@"anotherKey":@"anotherValue"};//原来的字典
NSDictionary *mappingDic = @{@"key":@"newKey"};//映射字典,这里只映射一个Key
NSDictionary *newDic = [oringinDic zbRemapKeyWithMappingDictionary:mappingDic removingNullValues:YES];
NSLog(@"映射后的 Dic: %@", newDic);

打印一下

映射前: {
  key = value;
  anotherKey = anotherValue;
}
映射后: {
  newKey = value;
  anotherKey = anotherValue;
}