NSDictionary *dict = @{@"subModel":@{@"name":@"Nomy",
@"age":@5},
@"name":@"Arron",
@"age":@33,
@"infoDict":@{@"submodel":@{@"gender":@1,@"name":@"YYmodel"}},
};
XLModel *model = [XLModel yy_modelWithDictionary:dict];
YYModel 是进行键值编码，做字典转模型的事情。 分析对象：是对象Model包括Ivar成员变量 结果返回一个值
Class cls = [self class];
_YYModelMeta *modelMeta = [_YYModelMeta metaWithClass:cls];
首先，我将分析的对象类传进来，准备我们当前需要操作的对象
/// Returns the cached model class meta
+ (instancetype)metaWithClass:(Class)cls {
if (!cls) return nil;
static CFMutableDictionaryRef cache;
static dispatch_once_t onceToken;
static dispatch_semaphore_t lock;
dispatch_once(&onceToken, ^{
cache = CFDictionaryCreateMutable(CFAllocatorGetDefault(), 0, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
lock = dispatch_semaphore_create(1);
});
dispatch_semaphore_wait(lock, DISPATCH_TIME_FOREVER);
_YYModelMeta *meta = CFDictionaryGetValue(cache, (__bridge const void *)(cls));
dispatch_semaphore_signal(lock);
if (!meta || meta->_classInfo.needUpdate) {
meta = [[_YYModelMeta alloc] initWithClass:cls];
if (meta) {
dispatch_semaphore_wait(lock, DISPATCH_TIME_FOREVER);
CFDictionarySetValue(cache, (__bridge const void *)(cls), (__bridge const void *)(meta));
dispatch_semaphore_signal(lock);
}
}
return meta;
}
YYModel之所以性能高，是由于做了一些类型系统级别的缓存处理，如果我们对象类做过字典转模型的处理后，他就会缓存到通过 CFMutableDictionaryRef创建一个字典中。再次使用就会直接从cache中拿出来，通过CFDictionaryGetValue。
如果没有cache，接下来看一下是如何处理metaClass的
`- (instancetype)initWithClass:(Class)cls { YYClassInfo *classInfo = [YYClassInfo classInfoWithClass:cls]; if (!classInfo) return nil; self = [super init];
1. 处理黑名单
// Get black list
NSSet *blacklist = nil;
if ([cls respondsToSelector:@selector(modelPropertyBlacklist)]) {
NSArray *properties = [(id<YYModel>)cls modelPropertyBlacklist];
if (properties) {
blacklist = [NSSet setWithArray:properties];
}
}
2. 处理白名单
// Get white list
NSSet *whitelist = nil;
if ([cls respondsToSelector:@selector(modelPropertyWhitelist)]) {
NSArray *properties = [(id<YYModel>)cls modelPropertyWhitelist];
if (properties) {
whitelist = [NSSet setWithArray:properties];
}
}
3. 属性替换-处理特殊集合或其他的类型
// Get container property's generic class
NSDictionary *genericMapper = nil;
if ([cls respondsToSelector:@selector(modelContainerPropertyGenericClass)]) {
genericMapper = [(id<YYModel>)cls modelContainerPropertyGenericClass];
if (genericMapper) {
NSMutableDictionary *tmp = [NSMutableDictionary new];
[genericMapper enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
if (![key isKindOfClass:[NSString class]]) return;
Class meta = object_getClass(obj);
if (!meta) return;
if (class_isMetaClass(meta)) {
tmp[key] = obj;
} else if ([obj isKindOfClass:[NSString class]]) {
Class cls = NSClassFromString(obj);
if (cls) {
tmp[key] = cls;
}
}
}];
genericMapper = tmp;
}
}
4. 处理所有元类的属性
// Create all property metas.
NSMutableDictionary *allPropertyMetas = [NSMutableDictionary new];
YYClassInfo *curClassInfo = classInfo;
while (curClassInfo && curClassInfo.superCls != nil) { // recursive parse super class, but ignore root class (NSObject/NSProxy)
for (YYClassPropertyInfo *propertyInfo in curClassInfo.propertyInfos.allValues) {
if (!propertyInfo.name) continue;
if (blacklist && [blacklist containsObject:propertyInfo.name]) continue;
if (whitelist && ![whitelist containsObject:propertyInfo.name]) continue;
_YYModelPropertyMeta *meta = [_YYModelPropertyMeta metaWithClassInfo:classInfo
propertyInfo:propertyInfo
generic:genericMapper[propertyInfo.name]];
if (!meta || !meta->_name) continue;
if (!meta->_getter || !meta->_setter) continue;
if (allPropertyMetas[meta->_name]) continue;
allPropertyMetas[meta->_name] = meta;
}
curClassInfo = curClassInfo.superClassInfo;
}
if (allPropertyMetas.count) _allPropertyMetas = allPropertyMetas.allValues.copy;
5. 遍历类和父类的所有属性，存放到map中
// create mapper
NSMutableDictionary *mapper = [NSMutableDictionary new];
NSMutableArray *keyPathPropertyMetas = [NSMutableArray new];
NSMutableArray *multiKeysPropertyMetas = [NSMutableArray new];
if ([cls respondsToSelector:@selector(modelCustomPropertyMapper)]) {
NSDictionary *customMapper = [(id <YYModel>)cls modelCustomPropertyMapper];
[customMapper enumerateKeysAndObjectsUsingBlock:^(NSString *propertyName, NSString *mappedToKey, BOOL *stop) {
_YYModelPropertyMeta *propertyMeta = allPropertyMetas[propertyName];
if (!propertyMeta) return;
[allPropertyMetas removeObjectForKey:propertyName];
if ([mappedToKey isKindOfClass:[NSString class]]) {
if (mappedToKey.length == 0) return;
propertyMeta->_mappedToKey = mappedToKey;
NSArray *keyPath = [mappedToKey componentsSeparatedByString:@"."];
for (NSString *onePath in keyPath) {
if (onePath.length == 0) {
NSMutableArray *tmp = keyPath.mutableCopy;
[tmp removeObject:@""];
keyPath = tmp;
break;
}
}
if (keyPath.count > 1) {
propertyMeta->_mappedToKeyPath = keyPath;
[keyPathPropertyMetas addObject:propertyMeta];
}
propertyMeta->_next = mapper[mappedToKey] ?: nil;
mapper[mappedToKey] = propertyMeta;
} else if ([mappedToKey isKindOfClass:[NSArray class]]) {
NSMutableArray *mappedToKeyArray = [NSMutableArray new];
for (NSString *oneKey in ((NSArray *)mappedToKey)) {
if (![oneKey isKindOfClass:[NSString class]]) continue;
if (oneKey.length == 0) continue;
NSArray *keyPath = [oneKey componentsSeparatedByString:@"."];
if (keyPath.count > 1) {
[mappedToKeyArray addObject:keyPath];
} else {
[mappedToKeyArray addObject:oneKey];
}
if (!propertyMeta->_mappedToKey) {
propertyMeta->_mappedToKey = oneKey;
propertyMeta->_mappedToKeyPath = keyPath.count > 1 ? keyPath : nil;
}
}
if (!propertyMeta->_mappedToKey) return;
propertyMeta->_mappedToKeyArray = mappedToKeyArray;
[multiKeysPropertyMetas addObject:propertyMeta];
propertyMeta->_next = mapper[mappedToKey] ?: nil;
mapper[mappedToKey] = propertyMeta;
}
}];
}
[allPropertyMetas enumerateKeysAndObjectsUsingBlock:^(NSString *name, _YYModelPropertyMeta *propertyMeta, BOOL *stop) {
propertyMeta->_mappedToKey = name;
propertyMeta->_next = mapper[name] ?: nil;
mapper[name] = propertyMeta;
}];
if (mapper.count) _mapper = mapper;
if (keyPathPropertyMetas) _keyPathPropertyMetas = keyPathPropertyMetas;
if (multiKeysPropertyMetas) _multiKeysPropertyMetas = multiKeysPropertyMetas;
_classInfo = classInfo;
_keyMappedCount = _allPropertyMetas.count;
_nsType = YYClassGetNSType(cls);
_hasCustomWillTransformFromDictionary = ([cls instancesRespondToSelector:@selector(modelCustomWillTransformFromDictionary:)]);
_hasCustomTransformFromDictionary = ([cls instancesRespondToSelector:@selector(modelCustomTransformFromDictionary:)]);
_hasCustomTransformToDictionary = ([cls instancesRespondToSelector:@selector(modelCustomTransformToDictionary:)]);
_hasCustomClassFromDictionary = ([cls respondsToSelector:@selector(modelCustomClassForDictionary:)]);
return self;
}`
metaClass准备好后，接下来通过当前对象new新的对象，都是通过发送setter消息进行赋值
NSObject *one = [cls new];
if ([one yy_modelSetWithDictionary:dictionary]) return one;
if (value) {
__unsafe_unretained id model = (__bridge id)(context->model);
ModelSetValueForProperty(model, value, propertyMeta);
}
