項目中使用JSONModel解析接口返回時，遇到一個model對應多個接口字段，例如

A:
contacts = (
{
  contactId = xx;
  contactName = "xx";
},
{
  contactId = xx;
  contactName = "xx";
}
);

B:
contacts = (
{
  id = xx;
  name = "xxx";
},
{
  id = xx;
  name = "xx";
}
);

對應的model

@protocol MSContactModel;

@interface MSContactModel : JSONModel

@property (nonatomic, strong) NSString *name;
@property (nonatomic, strong) NSString *contactType;
@property (nonatomic, strong) NSString *cellphone;
@property (nonatomic, strong) NSString *telephone;
@property (nonatomic, strong) NSString *email;
@property (nonatomic, strong) NSString *contactId;

@end

.m

+(JSONKeyMapper *)keyMapper
{
  NSMutableDictionary *keyMapper = [NSMutableDictionary dictionary];
  [keyMapper setObject:@"id" forKey:@"contactId"];
  [keyMapper setObject:@"name" forKey:@"contactName"];
  return [[JSONKeyMapper alloc] initWithDictionary:keyMapper];
}

這樣會造成接口返回字段為name時，不能正確解析。
原因是
JSONModel.m

-(BOOL)__importDictionary:(NSDictionary*)dict withKeyMapper:(JSONKeyMapper*)keyMapper validation:(BOOL)validation error:(NSError**)err
{
    //loop over the incoming keys and set self's properties
    for (JSONModelClassProperty* property in [self __properties__]) {
        
        //convert key name ot model keys, if a mapper is provided
        NSString* jsonKeyPath = (keyMapper||globalKeyMapper) ? [self __mapString:property.name withKeyMapper:keyMapper importing:YES] : property.name;//這里會根據(jù)keyMapper返回
        //JMLog(@"keyPath: %@", jsonKeyPath);
        
        //general check for data type compliance
        id jsonValue;
        @try {
            jsonValue = [dict valueForKeyPath: jsonKeyPath];
        }
        @catch (NSException *exception) {
            jsonValue = dict[jsonKeyPath];
        }

解決方法
JSONModel.m

-(BOOL)__importDictionary:(NSDictionary*)dict withKeyMapper:(JSONKeyMapper*)keyMapper validation:(BOOL)validation error:(NSError**)err
{
    //loop over the incoming keys and set self's properties
    for (JSONModelClassProperty* property in [self __properties__]) {
        
        //convert key name ot model keys, if a mapper is provided
        NSString*jsonKeyPath = nil;
        //JMLog(@"keyPath: %@", jsonKeyPath);
        
        //這里先判斷是否可以直接解析
        if (dict[property.name]) {
            jsonKeyPath = property.name;
        }else{
            jsonKeyPath = (keyMapper) ? [self __mapString:property.name withKeyMapper:keyMapper importing:YES] : property.name;
        }
        //general check for data type compliance
        id jsonValue;
        @try {
            jsonValue = [dict valueForKeyPath: jsonKeyPath];
        }
        @catch (NSException *exception) {
            jsonValue = dict[jsonKeyPath];
        }

由于直接修改源碼會導致，更新pod的時候會被覆蓋，所以創(chuàng)建Category
JSONModel+Track

JSONModel+Track.m

...........
if (dict[property.name]) {
            jsonKeyPath = property.name;
        }else{
            jsonKeyPath = (keyMapper) ? [self __mapString:property.name withKeyMapper:keyMapper importing:YES] : property.name;
        }
...........

代碼 FixJSONModel

參考

Single Model with multiple KeyMappers for serializing
JSONModel命名中的駝峰(CamelCase)與下劃線 (UnderscoreCase)