ObjectMapper + RealmSwift 空值校验

需求, 在通过ObjectMapper解析时, 若value不满足条件整个对象返回nil

• 演示demo:

import Foundation
import ObjectMapper
import RealmSwift

class TestFModel: Object, Mappable {

    @objc dynamic var version: String?
    @objc dynamic var isOnlie: Bool = false

    // 索引
    override static func indexedProperties() -> [String] {
       return ["version"]
    }

    required convenience init?(map: Map) {
        if !map["isOnline", ignoreNil: true].isKeyPresent
            || !map["Version", ignoreNil: true].isKeyPresent {
            log(" ====> 参数校验失败")
            return nil
        }
        log(" 参数校验通过 ")
        self.init()
    }

    func mapping(map: Map) {
        isOnlie                 <- map["isOnline"]
        version                 <- map["version"]
    }
}

• 最开始只使用了!map["isOnline"].isKeyPresent来做判定, 发现预期不一致, 翻看了源码

  • 

    private func `subscript`(key: String, nested: Bool? = nil, delimiter: String = ".", ignoreNil: Bool = false) -> Map {
        // save key and value associated to it
        currentKey = key
        keyIsNested = nested ?? key.contains(delimiter)
        nestedKeyDelimiter = delimiter
    
        if mappingType == .fromJSON {
            // check if a value exists for the current key
            // do this pre-check for performance reasons
            if keyIsNested {
                // break down the components of the key that are separated by delimiter
                (isKeyPresent, currentValue) = valueFor(ArraySlice(key.components(separatedBy: delimiter)), dictionary: JSON)
            } else {
                let object = JSON[key]
                let isNSNull = object is NSNull
                isKeyPresent = isNSNull ? true : object != nil
                currentValue = isNSNull ? nil : object
            }
    
            // update isKeyPresent if ignoreNil is true
            if ignoreNil && currentValue == nil {
                isKeyPresent = false
            }
        }
    
        return self
    }
    

    第116行ignoreNil