我有两个对象:oldObj和newObj。

oldObj中的数据用于填充表单,而newObj是用户更改该表单中的数据并提交的结果。

这两个物体都很深。它们具有对象或对象数组等属性-它们可以有n层深,因此diff算法需要递归。

现在我不仅需要弄清楚从oldObj到newObj更改了什么(如添加/更新/删除),而且还需要知道如何最好地表示它。

到目前为止,我的想法只是构建一个通用的deepdiffbetweenobjects方法,该方法将返回窗体上的对象{add:{…},upd:{…},del:{…但我转念一想:以前一定有人需要它。

所以…有没有人知道一个库或一段代码可以做到这一点,并且可能有更好的方式来表示差异(以一种仍然是JSON可序列化的方式)?

更新:

我想到了一个更好的方法来表示更新的数据,通过使用与newObj相同的对象结构,但将所有属性值转换为窗体上的对象:

{type: '<update|create|delete>', data: <propertyValue>}

如果newObj。prop1 = 'new value'和oldObj。prop1 = 'old value'它将设置returnbj。Prop1 = {type: 'update', data: 'new value'}

更新2:

当我们处理数组的属性时,它会变得非常麻烦,因为数组[1,2,3]应该被计算为等于[2,3,1],这对于基于值的类型的数组(如string, int和bool)来说足够简单,但是当涉及到引用类型的数组(如对象和数组)时就很难处理了。

数组的示例应该是相等的:

[1,[{c: 1},2,3],{a:'hey'}] and [{a:'hey'},1,[3,{c: 1},2]]

不仅要检查这种类型的深度值相等相当复杂,而且要找出一种表示可能发生的变化的好方法。


当前回答

从sbgoran的答案中得到扩展和简化的函数。 这允许深度扫描和发现数组的相似性。

var result = objectDifference({ a:'i am unchanged', b:'i am deleted', e: {a: 1,b:false, c: null}, f: [1,{a: 'same',b:[{a:'same'},{d: 'delete'}]}], g: new Date('2017.11.25'), h: [1,2,3,4,5] }, { a:'i am unchanged', c:'i am created', e: {a: '1', b: '', d:'created'}, f: [{a: 'same',b:[{a:'same'},{c: 'create'}]},1], g: new Date('2017.11.25'), h: [4,5,6,7,8] }); console.log(result); function objectDifference(obj1, obj2){ if((dataType(obj1) !== 'array' && dataType(obj1) !== 'object') || (dataType(obj2) !== 'array' && dataType(obj2) !== 'object')){ var type = ''; if(obj1 === obj2 || (dataType(obj1) === 'date' && dataType(obj2) === 'date' && obj1.getTime() === obj2.getTime())) type = 'unchanged'; else if(dataType(obj1) === 'undefined') type = 'created'; if(dataType(obj2) === 'undefined') type = 'deleted'; else if(type === '') type = 'updated'; return { type: type, data:(obj1 === undefined) ? obj2 : obj1 }; } if(dataType(obj1) === 'array' && dataType(obj2) === 'array'){ var diff = []; obj1.sort(); obj2.sort(); for(var i = 0; i < obj2.length; i++){ var type = obj1.indexOf(obj2[i]) === -1?'created':'unchanged'; if(type === 'created' && (dataType(obj2[i]) === 'array' || dataType(obj2[i]) === 'object')){ diff.push( objectDifference(obj1[i], obj2[i]) ); continue; } diff.push({ type: type, data: obj2[i] }); } for(var i = 0; i < obj1.length; i++){ if(obj2.indexOf(obj1[i]) !== -1 || dataType(obj1[i]) === 'array' || dataType(obj1[i]) === 'object') continue; diff.push({ type: 'deleted', data: obj1[i] }); } } else { var diff = {}; var key = Object.keys(obj1); for(var i = 0; i < key.length; i++){ var value2 = undefined; if(dataType(obj2[key[i]]) !== 'undefined') value2 = obj2[key[i]]; diff[key[i]] = objectDifference(obj1[key[i]], value2); } var key = Object.keys(obj2); for(var i = 0; i < key.length; i++){ if(dataType(diff[key[i]]) !== 'undefined') continue; diff[key[i]] = objectDifference(undefined, obj2[key[i]]); } } return diff; } function dataType(data){ if(data === undefined || data === null) return 'undefined'; if(data.constructor === String) return 'string'; if(data.constructor === Array) return 'array'; if(data.constructor === Object) return 'object'; if(data.constructor === Number) return 'number'; if(data.constructor === Boolean) return 'boolean'; if(data.constructor === Function) return 'function'; if(data.constructor === Date) return 'date'; if(data.constructor === RegExp) return 'regex'; return 'unknown'; }

其他回答

我写了一个小类来做你想做的,你可以在这里测试。

唯一不同于你的建议的是我不考虑

[1,[{c: 1},2,3],{a:'hey'}]

and

[{a:'hey'},1,[3,{c: 1},2]]

相等,因为我认为数组中元素的顺序不相等。当然,如果需要,这可以改变。此外,这段代码还可以进一步增强,将函数作为参数,用于基于传递的原语值以任意方式格式化diff对象(现在这项工作由"compareValues"方法完成)。

var deepDiffMapper = function () { return { VALUE_CREATED: 'created', VALUE_UPDATED: 'updated', VALUE_DELETED: 'deleted', VALUE_UNCHANGED: 'unchanged', map: function(obj1, obj2) { if (this.isFunction(obj1) || this.isFunction(obj2)) { throw 'Invalid argument. Function given, object expected.'; } if (this.isValue(obj1) || this.isValue(obj2)) { return { type: this.compareValues(obj1, obj2), data: obj1 === undefined ? obj2 : obj1 }; } var diff = {}; for (var key in obj1) { if (this.isFunction(obj1[key])) { continue; } var value2 = undefined; if (obj2[key] !== undefined) { value2 = obj2[key]; } diff[key] = this.map(obj1[key], value2); } for (var key in obj2) { if (this.isFunction(obj2[key]) || diff[key] !== undefined) { continue; } diff[key] = this.map(undefined, obj2[key]); } return diff; }, compareValues: function (value1, value2) { if (value1 === value2) { return this.VALUE_UNCHANGED; } if (this.isDate(value1) && this.isDate(value2) && value1.getTime() === value2.getTime()) { return this.VALUE_UNCHANGED; } if (value1 === undefined) { return this.VALUE_CREATED; } if (value2 === undefined) { return this.VALUE_DELETED; } return this.VALUE_UPDATED; }, isFunction: function (x) { return Object.prototype.toString.call(x) === '[object Function]'; }, isArray: function (x) { return Object.prototype.toString.call(x) === '[object Array]'; }, isDate: function (x) { return Object.prototype.toString.call(x) === '[object Date]'; }, isObject: function (x) { return Object.prototype.toString.call(x) === '[object Object]'; }, isValue: function (x) { return !this.isObject(x) && !this.isArray(x); } } }(); var result = deepDiffMapper.map({ a: 'i am unchanged', b: 'i am deleted', e: { a: 1, b: false, c: null }, f: [1, { a: 'same', b: [{ a: 'same' }, { d: 'delete' }] }], g: new Date('2017.11.25') }, { a: 'i am unchanged', c: 'i am created', e: { a: '1', b: '', d: 'created' }, f: [{ a: 'same', b: [{ a: 'same' }, { c: 'create' }] }, 1], g: new Date('2017.11.25') }); console.log(result);

下面是一个JavaScript库,可以用来查找两个JavaScript对象之间的差异:

Github URL: https://github.com/cosmicanant/recursive-diff

npm捷的url:北京方位www.npmjs.犯下/ recursiff

递归-diff库可以在浏览器中使用,也可以在基于Node.js的服务器端应用程序中使用。对于浏览器,它可以使用如下:

<script type="text" src="https://unpkg.com/recursive-diff@latest/dist/recursive-diff.min.js"/>
<script type="text/javascript">
     const ob1 = {a:1, b: [2,3]};
     const ob2 = {a:2, b: [3,3,1]};
     const delta = recursiveDiff.getDiff(ob1,ob2); 
     /* console.log(delta) will dump following data 
     [
         {path: ['a'], op: 'update', val: 2}
         {path: ['b', '0'], op: 'update',val: 3},
         {path: ['b',2], op: 'add', val: 1 },
     ]
      */
     const ob3 = recursiveDiff.applyDiff(ob1, delta); //expect ob3 is deep equal to ob2
 </script>

而在一个基于node.js的应用程序中,它可以这样使用:

const diff = require('recursive-diff');
const ob1 = {a: 1}, ob2: {b:2};
const diff = diff.getDiff(ob1, ob2);

我已经使用这段代码来完成你所描述的任务:

function mergeRecursive(obj1, obj2) {
    for (var p in obj2) {
        try {
            if(obj2[p].constructor == Object) {
                obj1[p] = mergeRecursive(obj1[p], obj2[p]);
            }
            // Property in destination object set; update its value.
            else if (Ext.isArray(obj2[p])) {
                // obj1[p] = [];
                if (obj2[p].length < 1) {
                    obj1[p] = obj2[p];
                }
                else {
                    obj1[p] = mergeRecursive(obj1[p], obj2[p]);
                }

            }else{
                obj1[p] = obj2[p];
            }
        } catch (e) {
            // Property in destination object not set; create it and set its value.
            obj1[p] = obj2[p];
        }
    }
    return obj1;
}

这将为您提供一个新对象,该对象将合并窗体中的旧对象和新对象之间的所有更改

从sbgoran的答案中得到扩展和简化的函数。 这允许深度扫描和发现数组的相似性。

var result = objectDifference({ a:'i am unchanged', b:'i am deleted', e: {a: 1,b:false, c: null}, f: [1,{a: 'same',b:[{a:'same'},{d: 'delete'}]}], g: new Date('2017.11.25'), h: [1,2,3,4,5] }, { a:'i am unchanged', c:'i am created', e: {a: '1', b: '', d:'created'}, f: [{a: 'same',b:[{a:'same'},{c: 'create'}]},1], g: new Date('2017.11.25'), h: [4,5,6,7,8] }); console.log(result); function objectDifference(obj1, obj2){ if((dataType(obj1) !== 'array' && dataType(obj1) !== 'object') || (dataType(obj2) !== 'array' && dataType(obj2) !== 'object')){ var type = ''; if(obj1 === obj2 || (dataType(obj1) === 'date' && dataType(obj2) === 'date' && obj1.getTime() === obj2.getTime())) type = 'unchanged'; else if(dataType(obj1) === 'undefined') type = 'created'; if(dataType(obj2) === 'undefined') type = 'deleted'; else if(type === '') type = 'updated'; return { type: type, data:(obj1 === undefined) ? obj2 : obj1 }; } if(dataType(obj1) === 'array' && dataType(obj2) === 'array'){ var diff = []; obj1.sort(); obj2.sort(); for(var i = 0; i < obj2.length; i++){ var type = obj1.indexOf(obj2[i]) === -1?'created':'unchanged'; if(type === 'created' && (dataType(obj2[i]) === 'array' || dataType(obj2[i]) === 'object')){ diff.push( objectDifference(obj1[i], obj2[i]) ); continue; } diff.push({ type: type, data: obj2[i] }); } for(var i = 0; i < obj1.length; i++){ if(obj2.indexOf(obj1[i]) !== -1 || dataType(obj1[i]) === 'array' || dataType(obj1[i]) === 'object') continue; diff.push({ type: 'deleted', data: obj1[i] }); } } else { var diff = {}; var key = Object.keys(obj1); for(var i = 0; i < key.length; i++){ var value2 = undefined; if(dataType(obj2[key[i]]) !== 'undefined') value2 = obj2[key[i]]; diff[key[i]] = objectDifference(obj1[key[i]], value2); } var key = Object.keys(obj2); for(var i = 0; i < key.length; i++){ if(dataType(diff[key[i]]) !== 'undefined') continue; diff[key[i]] = objectDifference(undefined, obj2[key[i]]); } } return diff; } function dataType(data){ if(data === undefined || data === null) return 'undefined'; if(data.constructor === String) return 'string'; if(data.constructor === Array) return 'array'; if(data.constructor === Object) return 'object'; if(data.constructor === Number) return 'number'; if(data.constructor === Boolean) return 'boolean'; if(data.constructor === Function) return 'function'; if(data.constructor === Date) return 'date'; if(data.constructor === RegExp) return 'regex'; return 'unknown'; }

这里有一个解决方案:

TypeScript(但很容易转换为JavaScript) 没有lib依赖项 泛型的,不关心检查对象类型(除了对象类型) 支持值为undefined的属性 深度不(默认)

首先,我们定义比较结果接口:

export interface ObjectDiff {
  added: {} | ObjectDiff;
  updated: {
    [propName: string]: Update | ObjectDiff;
  };
  removed: {} | ObjectDiff;
  unchanged: {} | ObjectDiff;
}

对于change的特殊情况,我们想知道什么是旧值和新值:

export interface Update {
  oldValue: any;
  newValue: any;
}

然后我们可以提供只有两个循环的diff函数(如果deep为真,则具有递归性):

export class ObjectUtils {
  /**
   * @return if obj is an Object, including an Array.
   */
  static isObject(obj: any) {
    return obj !== null && typeof obj === 'object';
  }

  /**
   * @param oldObj The previous Object or Array.
   * @param newObj The new Object or Array.
   * @param deep If the comparison must be performed deeper than 1st-level properties.
   * @return A difference summary between the two objects.
   */
  static diff(oldObj: {}, newObj: {}, deep = false): ObjectDiff {
    const added = {};
    const updated = {};
    const removed = {};
    const unchanged = {};
    for (const oldProp in oldObj) {
      if (oldObj.hasOwnProperty(oldProp)) {
        const newPropValue = newObj[oldProp];
        const oldPropValue = oldObj[oldProp];
        if (newObj.hasOwnProperty(oldProp)) {
          if (newPropValue === oldPropValue) {
            unchanged[oldProp] = oldPropValue;
          } else {
            updated[oldProp] = deep && this.isObject(oldPropValue) && this.isObject(newPropValue) ? this.diff(oldPropValue, newPropValue, deep) : {newValue: newPropValue};
          }
        } else {
          removed[oldProp] = oldPropValue;
        }
      }
    }
    for (const newProp in newObj) {
      if (newObj.hasOwnProperty(newProp)) {
        const oldPropValue = oldObj[newProp];
        const newPropValue = newObj[newProp];
        if (oldObj.hasOwnProperty(newProp)) {
          if (oldPropValue !== newPropValue) {
            if (!deep || !this.isObject(oldPropValue)) {
              updated[newProp].oldValue = oldPropValue;
            }
          }
        } else {
          added[newProp] = newPropValue;
        }
      }
    }
    return {added, updated, removed, unchanged};
  }
}

例如,调用:

ObjectUtils.diff(
  {
    a: 'a', 
    b: 'b', 
    c: 'c', 
    arr: ['A', 'B'], 
    obj: {p1: 'p1', p2: 'p2'}
  },
  {
    b: 'x', 
    c: 'c', 
    arr: ['B', 'C'], 
    obj: {p2: 'p2', p3: 'p3'}, 
    d: 'd'
  },
);

将返回:

{
  added: {d: 'd'},
  updated: {
    b: {oldValue: 'b', newValue: 'x'},
    arr: {oldValue: ['A', 'B'], newValue: ['B', 'C']},
    obj: {oldValue: {p1: 'p1', p2: 'p2'}, newValue: {p2: 'p2', p3: 'p3'}}
  },
  removed: {a: 'a'},
  unchanged: {c: 'c'},
}

对deep third参数调用同样的方法将返回:

{
  added: {d: 'd'},
  updated: {
    b: {oldValue: 'b', newValue: 'x'},
    arr: {
      added: {},
      removed: {},
      unchanged: {},
      updated: {
        0: {oldValue: 'A', newValue: 'B'},
        1: {oldValue: 'B', newValue: 'C', }
      }
    },
    obj: {
      added: {p3: 'p3'},
      removed: {p1: 'p1'},
      unchanged: {p2: 'p2'},
      updated: {}
    }
  },
  removed: {a: 'a'},
  unchanged: {c: 'c'},
}