淘汰 js 映射嵌套的可观察数组答案

【问题标题】：knockout js mapping nested observable arrays淘汰 js 映射嵌套的可观察数组
【发布时间】：2012-10-14 20:47:16
【问题描述】：

鉴于此 json 结构：

{
    "categoryID" : 1,
    "categoryName" : "Stupid Questions",
    "questions" : [{
            "question" : [{
                    "questionOptions" : [{
                            "questionOptionID" : 1,
                            "optionText" : "It's top secret."
                        }, {
                            "questionOptionID" : 2,
                            "optionText" : "Because I am big and your small. I am right and your wrong."
                        }, {
                            "questionOptionID" : 3,
                            "optionText" : "I will gladly pay you Tuesday for a hamburger today."
                        },
                    ],
                    "questionType" : "checkbox",
                    "questionText" : "Why can't we use more abstract table and column names?",
                    "summary" : "Question of the year"
                }
            ]
        }
    ]
}

我想将 questions 和 questionOptions 都映射到 template 和 templateOptions：

{
    "categoryID" : 1,
    "categoryName" : "Stupid Questions",
    "templates" : [{
            "template" : [{
                    "templateOptions" : [{
                            "templateOptionID" : 1,
                            "optionText" : "It is top secret."
                        }, {
                            "QuestionOptionID" : 2,
                            "OptionText" : "Because we are lazy."
                        }, {
                            "QuestionOptionID" : 3,
                            "OptionText" : "I will gladly pay you Tuesday for a hamburger today."
                        },
                    ],
                    "QuestionType" : "checkbox",
                    "QuestionText" : "Why can't we use more abstract table and column names?",
                    "Summary" : "Question of the year"
                }
            ]
        }
    ]
}

这是我的淘汰映射对象的开始：

var templateMapping = {
  'templates': {
      templates: function(data) {
          return ko.utils.unwrapObservable(data.questions);
      }
  }
  //how do I map observable array of question options to observable  array of template options here?
};

这个映射的关键是子对象有不同的结构（不像这个问题 - https://stackoverflow.com/a/7535397/466321）。似乎我发现的所有映射示例都没有涵盖如何完成此操作，而且我尝试了自己的几个理论都没有成功。

【问题讨论】：

映射器不是这样工作的。我采用对象模型并使属性可观察。这不是故意的。

标签： json knockout.js knockout-mapping-plugin

【解决方案1】：

@Jeff Mercado 是对的。映射器不适用于此。要完成您的意图，需要一些递归 javascript。

function myTransform(string) {
    // case-insensitive replace
    return string.replace(/question/i,'template');
}

function transformObject(source) {
    var result = {}
    for( var key in source ) {
        if( !source.hasOwnProperty(key) ) continue;
        var value = source[key];
        var newKey = myTransform(key);
        if( Object.prototype.toString.call(value) == "[object Array]" ) {
            result[newKey] = [];
            for( var i in value ) {
                if( !value.hasOwnProperty(i) ) continue;
                result[newKey][i] = transformObject(value[i]);
            }
        }
        else if( Object.prototype.toString.call(value) == "[object Object]" ) {
            result[newKey] = transformObject(value);
        }
        else {
            result[newKey] = value;
        }
    }
    return result;
}

var wow = transformObject(json);

看到这个fiddle

【讨论】：