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

const diff = require("deep-object-diff").diff;
let differences = diff(obj2, obj1);

有一个每周下载量超过50万的npm模块:https://www.npmjs.com/package/deep-object-diff

我喜欢对象式的差异表示-特别是当它形成时,很容易看到结构。

const diff = require("deep-object-diff").diff;

const lhs = {
  foo: {
    bar: {
      a: ['a', 'b'],
      b: 2,
      c: ['x', 'y'],
      e: 100 // deleted
    }
  },
  buzz: 'world'
};

const rhs = {
  foo: {
    bar: {
      a: ['a'], // index 1 ('b')  deleted
      b: 2, // unchanged
      c: ['x', 'y', 'z'], // 'z' added
      d: 'Hello, world!' // added
    }
  },
  buzz: 'fizz' // updated
};

console.log(diff(lhs, rhs)); // =>
/*
{
  foo: {
    bar: {
      a: {
        '1': undefined
      },
      c: {
        '2': 'z'
      },
      d: 'Hello, world!',
      e: undefined
    }
  },
  buzz: 'fizz'
}
*/

其他回答

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

var base = [
{"value": "01", "label": "Pendências"},
{"value": "02", "label": "Ambulatório"},
{"value": "03", "label": "Urgência"},
{"value": "04", "label": "Clínica Médica"},
{"value": "05", "label": "Revisão"},
{"value": "06", "label": "Imagens"},
];

var used = [
{"value": "01", "label": "Pendências"},
{"value": "02", "label": "Ambulatório"},
{"value": "03", "label": "Urgência"},
{"value": "04", "label": "Clínica Médica"},
];

function diff(obj1,obj2) {
        var temp = JSON.stringify(obj2.map((x)=> x.value));
    return obj1.filter((y)=> temp.indexOf(y.value)<0 && y);
}


var result = diff(base, used); 
console.clear();
console.log('RESULTADO');
console.log(result);

codeped

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);

这是在gisthub上找到的一个修改版本。

isNullBlankOrUndefined = function (o) {
    return (typeof o === "undefined" || o == null || o === "");
}

/**
 * Deep diff between two object, using lodash
 * @param  {Object} object Object compared
 * @param  {Object} base   Object to compare with
 * @param  {Object} ignoreBlanks will not include properties whose value is null, undefined, etc.
 * @return {Object}        Return a new object who represent the diff
 */
objectDifference = function (object, base, ignoreBlanks = false) {
    if (!lodash.isObject(object) || lodash.isDate(object)) return object            // special case dates
    return lodash.transform(object, (result, value, key) => {
        if (!lodash.isEqual(value, base[key])) {
            if (ignoreBlanks && du.isNullBlankOrUndefined(value) && isNullBlankOrUndefined( base[key])) return;
            result[key] = lodash.isObject(value) && lodash.isObject(base[key]) ? objectDifference(value, base[key]) : value;
        }
    });
}

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'},
}