以父键为属性且键包含括号的 RestKit 映射

Question

上下文：

// JSON
"Name_Field" : {
    "param_1":"value_1",
    "param_2":"value_2"
}

// Class
class Field {
    name
    param1
    param2
}

// Mapping Functionality
[mapping addAttributeMappingFromKeyOfRepresentationToAttribute:@"name"];
[mapping addAttributeMappingsFromDictionary:@{
    @"(name).param_1":@"param1",
    @"(name).param_2":@"param2"
}];

问题：

我目前正在使用上述 JSON/类/映射代码。我已经使用了一段时间，一切都按预期工作。

今天我遇到了 JSON 中的键包含括号并导致映射失败的情况。有没有办法让它工作？

谢谢！

示例：

"Name (haha this will break)" : {
    "param_1":"value_1",
    "param_2":"value_2"
}

Answer 1

我认为RestKit 会感到困惑，因为它不知道映射时使用哪个括号。所以我的猜测是用大括号替换它们：

[mapping addAttributeMappingsFromDictionary:@{
    @"{name}.param_1":@"param1",
    @"{name}.param_2":@"param2"
}];

让我知道这是否有效。

Answer 2

解决方案：

更新RKPropertyMapping 中的RKStringByReplacingUnderscoresWithBraces 方法，不要用大括号替换括号，然后确保在属性映射中使用大括号。

// RKPropertyMapping
static NSString *RKStringByReplacingUnderscoresWithBraces(NSString *string)
{
    return string;
    //return [[string stringByReplacingOccurrencesOfString:@"(" withString:@"{"] stringByReplacingOccurrencesOfString:@")" withString:@"}"];
}


// Attribute Mappings
[mapping addAttributeMappingsFromDictionary:@{
    @"{name}.param_1":@"param1",
    @"{name}.param_2":@"param2"
}];

说明：

https://github.com/RestKit/RestKit/wiki/Object-mapping#handling-dynamic-nesting-attributes

在上述 RestKit 文档中，当您尝试将键映射到属性时，系统会指示您使用 addAttributeMappingFromKeyOfRepresentationToAttribute，然后使用括号映射嵌套键以表示您的属性，后跟“.”。和你的嵌套键。

在 RestKit 中，在从 addAttributeMappingFromKeyOfRepresentationToAttribute 属性映射执行映射后，它会循环遍历所有定义的属性映射，以将占位符替换为键中的实际值，以便可以进行额外的映射操作。在此过程中，它创建一个新的RKPropertyMapping 对象并设置它的sourceKeyPath 和destinationKeyPath。这些属性的属性设置器获取值并用大括号替换括号，然后 RestKit 不会找到带大括号的值的不正确映射。

示例上下文：

// JSON   
{ "blake": {
    "email": "blake@restkit.org",
    "favorite_animal": "Monkey"
    }
}

// Class
@interface User : NSObject
@property (nonatomic, copy) NSString* email
@property (nonatomic, copy) NSString* username;
@property (nonatomic, copy) NSString* favoriteAnimal;
@end

// Mapping
RKObjectMapping* mapping = [RKObjectMapping mappingForClass:[User class] ];
[mapping addAttributeMappingFromKeyOfRepresentationToAttribute:@"username"];
[mapping addAttributeMappingsFromDictionary:@{
    @"(username).email": @"email",
    @"(username).favorite_animal": @"favoriteAnimal"
}];

示例映射：

// Resulting Attribute Mappings
@"{username}.email": @"email",
@"{username}.favorite_animal": @"favoriteAnimal"


// 1. The attribute mapping has been performed for 'blake' > 'username'
// 2. RestKit now loops through your attribute mappings to replace '{username}' with 'blake' so your further nested attribute mappings can take place
// 3. Example: @"{username}.email": @"email"
      sourceKeyPath = @"{username}.email"
      destinationKeyPath = @"email"

      * replaces values *
      sourceKeyPath = @"blake.email"
      destinationKeyPath = @"email"

      * creates a new RKPropertyMapping object *
      RKPropertyMapping
        - sourceKeyPath = @"blake.email"
        - destinationKeyPath = @"email"

带括号的示例映射：

// JSON   
{ "blake (a.k.a GOAT)": {
    "email": "blake@restkit.org",
    "favorite_animal": "Monkey"
    }
}

// Resulting Attribute Mappings
@"{username}.email": @"email",
@"{username}.favorite_animal": @"favoriteAnimal"


// 1. The attribute mapping has been performed for 'blake (a.k.a GOAT)' > 'username'
// 2. RestKit now loops through your attribute mappings to replace '{username}' with 'blake (a.k.a GOAT)' so your further nested attribute mappings can take place
// 3. Example: @"{username}.email": @"email"
      sourceKeyPath = @"{username}.email"
      destinationKeyPath = @"email"

      * replaces values *
      sourceKeyPath = @"blake (a.k.a GOAT).email"
      destinationKeyPath = @"email"

      * creates a new RKPropertyMapping object *
      RKPropertyMapping
        - sourceKeyPath = @"blake {a.k.a GOAT}.email" // DOES NOT MATCH
        - destinationKeyPath = @"email"