Jas*_*ing 16 javascript diff json data-structures
我希望能够获得两个JavaScript对象图之间所有差异的列表,以及发生增量的属性名称和值.
对于它的价值,这些对象通常作为JSON从服务器中检索,并且通常只有少数深层(即它可能是一个对象数组,它们本身具有数据,然后是与其他数据对象一起的数组).
我想不仅要看到基本属性的更改,还要看到数组成员数量的差异等.
如果我没有得到答案,我可能最终会自己写这篇文章,但希望有人已经完成了这项工作或者知道有人.
编辑:这些对象通常在结构上彼此非常接近,所以我们不是在讨论彼此完全不同的对象,而是可能有3或4个增量.
Jas*_*ing 20
这是我的问题的一个部分,天真的解决方案 - 我将在我进一步开发它时更新它.
function findDifferences(objectA, objectB) {
var propertyChanges = [];
var objectGraphPath = ["this"];
(function(a, b) {
if(a.constructor == Array) {
// BIG assumptions here: That both arrays are same length, that
// the members of those arrays are _essentially_ the same, and
// that those array members are in the same order...
for(var i = 0; i < a.length; i++) {
objectGraphPath.push("[" + i.toString() + "]");
arguments.callee(a[i], b[i]);
objectGraphPath.pop();
}
} else if(a.constructor == Object || (a.constructor != Number &&
a.constructor != String && a.constructor != Date &&
a.constructor != RegExp && a.constructor != Function &&
a.constructor != Boolean)) {
// we can safely assume that the objects have the
// same property lists, else why compare them?
for(var property in a) {
objectGraphPath.push(("." + property));
if(a[property].constructor != Function) {
arguments.callee(a[property], b[property]);
}
objectGraphPath.pop();
}
} else if(a.constructor != Function) { // filter out functions
if(a != b) {
propertyChanges.push({ "Property": objectGraphPath.join(""), "ObjectA": a, "ObjectB": b });
}
}
})(objectA, objectB);
return propertyChanges;
}
这里有一个如何使用它和它将提供的数据的样本(请原谅长的例子,但我想使用一些相对非平凡的东西):
var person1 = {
FirstName : "John",
LastName : "Doh",
Age : 30,
EMailAddresses : [
"john.doe@gmail.com",
"jd@initials.com"
],
Children : [
{
FirstName : "Sara",
LastName : "Doe",
Age : 2
}, {
FirstName : "Beth",
LastName : "Doe",
Age : 5
}
]
};
var person2 = {
FirstName : "John",
LastName : "Doe",
Age : 33,
EMailAddresses : [
"john.doe@gmail.com",
"jdoe@hotmail.com"
],
Children : [
{
FirstName : "Sara",
LastName : "Doe",
Age : 3
}, {
FirstName : "Bethany",
LastName : "Doe",
Age : 5
}
]
};
var differences = findDifferences(person1, person2);
此时,differences如果将序列化为JSON ,则数组的外观如下:
[
{
"Property":"this.LastName",
"ObjectA":"Doh",
"ObjectB":"Doe"
}, {
"Property":"this.Age",
"ObjectA":30,
"ObjectB":33
}, {
"Property":"this.EMailAddresses[1]",
"ObjectA":"jd@initials.com",
"ObjectB":"jdoe@hotmail.com"
}, {
"Property":"this.Children[0].Age",
"ObjectA":2,
"ObjectB":3
}, {
"Property":"this.Children[1].FirstName",
"ObjectA":"Beth",
"ObjectB":"Bethany"
}
]
的this在Property值是指被比较的对象的根.因此,该解决方案还没有正是我所需要的,但它是相当的接近.
希望这对那里的人有用,如果你有任何改进的建议,我全心全意; 我昨晚很晚才写到这个(即今天凌晨),我可能会完全忽视这些事情.
谢谢.
rya*_*anm 15
在查看现有答案后,我注意到https://github.com/flitbit/diff库尚未列为解决方案.
从我的研究来看,这个库在积极开发,贡献和分叉方面似乎是最好的,可以解决差异对象的挑战.这对于在服务器端创建差异并仅向客户端传递更改的位非常方便.
解决方案1
使用 JSON.stringify(obj) 获取要比较的对象的字符串表示形式。将字符串保存到文件中。使用任何差异查看器来比较文本文件。
注意：JSON.stringify 将忽略指向函数定义的属性。
解决方案2
这可以做你想做的一些修改，它是函数 _.isEqual ( http://documentcloud.github.com/underscore/ )的修改版本。请随时提出任何修改建议！我写它是为了找出两个对象之间的第一个差异发生在哪里。
// Given two objects find the first key or value not matching, algorithm is a
// inspired by of _.isEqual.
function diffObjects(a, b) {
console.info("---> diffObjects", {"a": a, "b": b});
// Check object identity.
if (a === b) return true;
// Different types?
var atype = typeof(a), btype = typeof(b);
if (atype != btype) {
console.info("Type mismatch:", {"a": a, "b": b});
return false;
};
// Basic equality test (watch out for coercions).
if (a == b) return true;
// One is falsy and the other truthy.
if ((!a && b) || (a && !b)) {
console.info("One is falsy and the other truthy:", {"a": a, "b": b});
return false;
}
// Unwrap any wrapped objects.
if (a._chain) a = a._wrapped;
if (b._chain) b = b._wrapped;
// One of them implements an isEqual()?
if (a.isEqual) return a.isEqual(b);
// Check dates' integer values.
if (_.isDate(a) && _.isDate(b)) return a.getTime() === b.getTime();
// Both are NaN?
if (_.isNaN(a) && _.isNaN(b)) {
console.info("Both are NaN?:", {"a": a, "b": b});
return false;
}
// Compare regular expressions.
if (_.isRegExp(a) && _.isRegExp(b))
return a.source === b.source &&
a.global === b.global &&
a.ignoreCase === b.ignoreCase &&
a.multiline === b.multiline;
// If a is not an object by this point, we can't handle it.
if (atype !== 'object') {
console.info("a is not an object:", {"a": a});
return false;
}
// Check for different array lengths before comparing contents.
if (a.length && (a.length !== b.length)) {
console.info("Arrays are of different length:", {"a": a, "b": b});
return false;
}
// Nothing else worked, deep compare the contents.
var aKeys = _.keys(a), bKeys = _.keys(b);
// Different object sizes?
if (aKeys.length != bKeys.length) {
console.info("Different object sizes:", {"a": a, "b": b});
return false;
}
// Recursive comparison of contents.
for (var key in a) if (!(key in b) || !diffObjects(a[key], b[key])) return false;
return true;
};
您还可以尝试rus-diff https://github.com/mirek/node-rus-diff,它会生成MongoDB兼容(重命名/取消设置/设置)差异.
对于您的示例对象:
var person1 = {
FirstName: "John",
LastName: "Doh",
Age: 30,
EMailAddresses: ["john.doe@gmail.com", "jd@initials.com"],
Children: [
{
FirstName: "Sara",
LastName: "Doe",
Age: 2
}, {
FirstName: "Beth",
LastName: "Doe",
Age: 5
}
]
};
var person2 = {
FirstName: "John",
LastName: "Doe",
Age: 33,
EMailAddresses: ["john.doe@gmail.com", "jdoe@hotmail.com"],
Children: [
{
FirstName: "Sara",
LastName: "Doe",
Age: 3
}, {
FirstName: "Bethany",
LastName: "Doe",
Age: 5
}
]
};
var rusDiff = require('rus-diff').rusDiff
console.log(rusDiff(person1, person2))
它会生成一组集:
{ '$set':
{ 'Age': 33,
'Children.0.Age': 3,
'Children.1.FirstName': 'Bethany',
'EMailAddresses.1': 'jdoe@hotmail.com',
'LastName': 'Doe' } }