Coredata toMany关系映射问题 - Swift

Question

我有两个表类别和子类别。

类别与SubCategory有很多关系。 SubCategory与SubCategory有很多关系。 （SubCategory可能有子类别）

数据库模型：

Json回复

{
"response": {
    "status": true,
    "message": "Category listed",
    "code": 200
},
"data": [
    {
        "description": "Memory Questions",
        "id": "QT05",
        "title": "Memory",
        "subcategory": [
            {
                "title": "Patterns",
                "id": "QT05P",
                "subcategory": [
                    {
                        "title": "Squares",
                        "id": "QT05PS",
                        "demo": {
                            "type": "image",
                            "value": "Memory/images/demo_QT05PS.png"
                        }
                    },
                    {
                        "title": "Circles",
                        "id": "QT05PC",
                        "demo": {
                            "type": "image",
                            "value": "Memory/images/demo_QT05PC.png"
                        }
                    },
                    {
                        "title": "Triangles",
                        "id": "QT05PT",
                        "demo": {
                            "type": "image",
                            "value": "Memory/images/demo_QT05PT.png"
                        }
                    },
                    {
                        "title": "Rectangles",
                        "id": "QT05PR",
                        "demo": {
                            "type": "image",
                            "value": "Memory/images/demo_QT05PR.png"
                        }
                    }
                ],
                "demo": {
                    "type": "image",
                    "value": "Memory/images/demo_QT05P.png"
                }
            }
        ]
    }
]

}

子类别模型类（CoreData）

extension SubCategory{
    func addSubCategory(subcategory:SubCategory) {
        var sub = self.mutableSetValueForKey("subcategories")
        sub.addObject(subcategory)
    }

    func setSubCategories(subCategories:NSArray){
        var sub = self.mutableSetValueForKey("subcategories")
        for subcategory in subCategories {
            sub.addObject(subcategory)
        }
    }
}

映射JSON

func mapCategory(dict:NSDictionary?) -> LUBaseResponse? {
    if (dict == nil) {
        return nil
    }
    var response = self.mapStatus(dict!)
    if (response != nil){
        if (response!.status == 1){
            let data:NSArray = dict!["data"] as NSArray
            var categoryArray = NSMutableArray()
            for categoryDict in data {
                if (self.fetchCategory(categoryDict["id"] as? String) == nil){
                    var category = NSEntityDescription.insertNewObjectForEntityForName("Category", inManagedObjectContext: self.managedObjectContext!) as? Category
                    category?.categoryDescription = categoryDict["description"] as String
                    category?.categoryId = categoryDict["id"] as String
                    category?.categoryTitle = categoryDict["title"] as String
                    var subcategory = self.mapSubcategory(categoryDict["subcategory"] as? NSArray,category: category!)
                    if (subcategory != nil && subcategory?.count > 0){
                        category?.setSubCategories(subcategory!)
                    }
                    categoryArray.addObject(category!)
                }
                LUCoreData.sharedInstance.saveContext()
            }
            response?.data = categoryArray

        }
    }
    return response
}



//Issue in this method
     private func mapSubcategory(array:NSArray?,category:Category) -> NSMutableArray? {
            var subcategoriesObjects = NSMutableArray()
            if (array?.count > 0){
                var subcategories = array!
                NSEntityDescription.insertNewObjectForEntityForName("SubCategory", inManagedObjectContext: self.managedObjectContext!) as? SubCategory
                for subcategoryDict in subcategories {
                    var title = subcategoryDict["title"]

                    if (self.fetchSubCategory(subcategoryDict["id"] as? String) == nil) {
                        var subcategory = NSEntityDescription.insertNewObjectForEntityForName("SubCategory", inManagedObjectContext: self.managedObjectContext!) as? SubCategory
                        subcategory?.title = subcategoryDict["title"] as String
                        subcategory?.id    = subcategoryDict["id"] as String
                        subcategory?.categoryOf = category

                        var arraySubCategory = subcategoryDict.objectForKey("subcategory") as? NSArray
                        if (arraySubCategory?.count > 0){
                            var nestedSubCategory = self.mapSubcategory(arraySubCategory,category: category)
                            if (nestedSubCategory != nil){
                            var sub = nestedSubCategory!.objectAtIndex(0) as SubCategory
                                println("Sub is \(sub.subcategories)") //Returns Empty
                                subcategory!.setSubCategories(nestedSubCategory!)
                               //Issue Here
                             println("Sub is \(sub.subcategories)") 
                            }
                        }
                        subcategoriesObjects.addObject(subcategory!)
                    }
                    LUCoreData.sharedInstance.saveContext()
                }
            }
            return subcategoriesObjects
        }

问题：

在JSON Response中，你可以看到Memory（Category）有子类别＆＃34; Patterns＆＃34;，它有嵌套的SubCategories＆＃34; Square＆＃34;，＆＃34; Circles＆＃34;等

这个循环在＆＃34; mapSubcategory＆＃34;中执行。功能

在这一行＆＃34;子类别之后！.setSubCategories（nestedSubCategory！）＆＃34;

在上面的图像中，您可以看到当嵌套子类别（＆＃34; Squares＆＃34;没有其他子类别）添加到父子类别时，父子类别（模式）被添加到Square作为子类别。这导致递归（Parent - ＆gt; Child - ＆gt; Parent - ＆gt; Child ....）。我不确定如何以递归方式将父母添加到孩子身上。

Answer 1

我已经通过从子类别表中删除反向关系来解决这个问题。