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» npm install json-diff
It's not too hard to create a function like this. Just loop through each field in the second object, and if it's not present in the first or the value is different than the first, put that field in the return object.
var compareJSON = function(obj1, obj2) {
var ret = {};
for(var i in obj2) {
if(!obj1.hasOwnProperty(i) || obj2[i] !== obj1[i]) {
ret[i] = obj2[i];
}
}
return ret;
};
You can see it in action on this demo page.
You can have a look at json diff wrapper here
It has also demo page.You can use this wrapper.
It's possible to use a recursive function that iterates by the object keys. Then use the Object.is to test for NaN and null. Then test if the second object is the type that cast to false like 0, NaN, or null.
List the keys of both objects and concatenate them to test of missing keys in the obj1 and then iterate it.
When there is a difference between the same key values, it stores the value of object2 and proceeds. If both key values are object means that can be recursively compared and so it does.
function diff(obj1, obj2) {
const result = {};
if (Object.is(obj1, obj2)) {
return undefined;
}
if (!obj2 || typeof obj2 !== 'object') {
return obj2;
}
Object.keys(obj1 || {}).concat(Object.keys(obj2 || {})).forEach(key => {
if(obj2[key] !== obj1[key] && !Object.is(obj1[key], obj2[key])) {
result[key] = obj2[key];
}
if(typeof obj2[key] === 'object' && typeof obj1[key] === 'object') {
const value = diff(obj1[key], obj2[key]);
if (value !== undefined) {
result[key] = value;
}
}
});
return result;
}
The code above is BSD licensed and can be used anywhere.
Test link: https://jsfiddle.net/gartz/vy9zaof2/54/
An important observation, this will convert arrays to objects and compare the values in the same index position. There are many other ways to compare arrays not covered by this function due to the required extra complexity.
EDIT 2/15/2019: This answer was changed to add the new ES2017 syntax and fix use-cases from comments.
This is just a kickoff, I haven't tested it, but I began with a filter or comparator function, that is recursive, change it however you need to get priority results.
function filter(obj1, obj2) {
var result = {};
for(key in obj1) {
if(obj2[key] != obj1[key]) result[key] = obj2[key];
if(typeof obj2[key] == 'array' && typeof obj1[key] == 'array')
result[key] = arguments.callee(obj1[key], obj2[key]);
if(typeof obj2[key] == 'object' && typeof obj1[key] == 'object')
result[key] = arguments.callee(obj1[key], obj2[key]);
}
return result;
}
Tests: http://jsfiddle.net/gartz/Q3BtG/2/
contributing back my changes to Gabriel Gartz version. This one works in strict mode and removes the array check - will always be false. It also removes empty nodes from the diff.
//http://stackoverflow.com/questions/679915/how-do-i-test-for-an-empty-javascript-object
var isEmptyObject = function(obj) {
var name;
for (name in obj) {
return false;
}
return true;
};
//http://stackoverflow.com/questions/8431651/getting-a-diff-of-two-json-objects
var diff = function(obj1, obj2) {
var result = {};
var change;
for (var key in obj1) {
if (typeof obj2[key] == 'object' && typeof obj1[key] == 'object') {
change = diff(obj1[key], obj2[key]);
if (isEmptyObject(change) === false) {
result[key] = change;
}
}
else if (obj2[key] != obj1[key]) {
result[key] = obj2[key];
}
}
return result;
};
Check out this python library jsondiff , that will help you to identify the diff's
import json
import jsondiff
json1 = json.loads(
'{"isDynamic": false, "name": "", "value": "SID:<sid>", "description": "instance","argsOrder": 1,"isMultiSelect": false}')
json2 = json.loads(
'{ "name": "", "value": "SID:<sid>","isDynamic": false, "description": "instance","argsOrder": 1,"isMultiSelect": false}')
res = jsondiff.diff(json1, json2)
if res:
print("Diff found")
else:
print("Same")
UPDATED: See https://eggachecat.github.io/jycm-json-diff-viewer/ for a live demo! Now it has a JS-native implementation.
Affiliation: I am the author of this lib.
Yes! You can diff it with jycm which has a rendering tool out of the box.
It uses LCS, Edit distance and Kuhn–Munkres to diff arrays.
Here's an universal example with set in set and value changes in some set
from jycm.helper import make_ignore_order_func
from jycm.jycm import YouchamaJsonDiffer
left = {
"set_in_set": [
{
"id": 1,
"label": "label:1",
"set": [
1,
5,
3
]
},
{
"id": 2,
"label": "label:2",
"set": [
4,
5,
6
]
}
]
}
right = {
"set_in_set": [
{
"id": 2,
"label": "label:2",
"set": [
6,
5,
4
]
},
{
"id": 1,
"label": "label:1111",
"set": [
3,
2,
1
]
}
]
}
ycm = YouchamaJsonDiffer(left, right, ignore_order_func=make_ignore_order_func([
"^set_in_set$",
"^set_in_set->\\[\\d+\\]->set$"
]))
ycm.diff()
expected = {
'list:add': [
{'left': '__NON_EXIST__', 'right': 2, 'left_path': '', 'right_path': 'set_in_set->[1]->set->[1]'}
],
'list:remove': [
{'left': 5, 'right': '__NON_EXIST__', 'left_path': 'set_in_set->[0]->set->[1]', 'right_path': ''}
],
'value_changes': [
{'left': 'label:1', 'right': 'label:1111', 'left_path': 'set_in_set->[0]->label',
'right_path': 'set_in_set->[1]->label', 'old': 'label:1', 'new': 'label:1111'}
]
}
assert ycm.to_dict(no_pairs=True) == expected
you can set no_pairs=False to get the all pairs. Here's a rendered example:

As for the example here, you can use it as:
from jycm.helper import make_ignore_order_func
from jycm.jycm import YouchamaJsonDiffer
left = {
"data": [{"x": 1, "y": 2}, {"x": 3, "y": 4}]
}
right = {
"data": [{"x": 3, "y": 4}, {"x": 1, "y": 2}]
}
ycm = YouchamaJsonDiffer(left, right, ignore_order_func=make_ignore_order_func([
"^data",
]))
ycm.diff()
assert ycm.to_dict(no_pairs=True) == {}
Bonus, you the values are interrupted as coordinates on plain, you can even define a operator to determine whether two points should be matched!(Then comparing their values)
Here's the code:
from typing import Tuple
from jycm.helper import make_ignore_order_func
from jycm.jycm import YouchamaJsonDiffer
from jycm.operator import BaseOperator
import math
left = {
"data": [
{"x": 1, "y": 1},
{"x": 10, "y": 10},
{"x": 100, "y": 100}
]
}
right = {
"data": [
{"x": 150, "y": 150},
{"x": 10, "y": 11},
{"x": 2, "y": 3}
]
}
class L2DistanceOperator(BaseOperator):
__operator_name__ = "operator:l2distance"
__event__ = "operator:l2distance"
def __init__(self, path_regex, distance_threshold):
super().__init__(path_regex=path_regex)
self.distance_threshold = distance_threshold
def diff(self, level: 'TreeLevel', instance, drill: bool) -> Tuple[bool, float]:
distance = math.sqrt(
(level.left["x"] - level.right["x"]) ** 2 + (level.left["y"] - level.right["y"]) ** 2
)
info = {
"distance": distance,
"distance_threshold": self.distance_threshold,
"pass": distance < self.distance_threshold
}
if not drill:
instance.report(self.__event__, level, info)
return False, 1 if info["pass"] else 0
return True, 1 if info["pass"] else 0
ycm = YouchamaJsonDiffer(left, right, ignore_order_func=make_ignore_order_func([
"^data$",
]), custom_operators=[
L2DistanceOperator("^data->\\[.*\\]$", 10),
])
ycm.diff()
expected = {
'just4vis:pairs': [
{'left': 1, 'right': 2, 'left_path': 'data->[0]->x', 'right_path': 'data->[2]->x'},
{'left': {'x': 1, 'y': 1}, 'right': {'x': 2, 'y': 3}, 'left_path': 'data->[0]',
'right_path': 'data->[2]'},
{'left': 1, 'right': 3, 'left_path': 'data->[0]->y', 'right_path': 'data->[2]->y'},
{'left': {'x': 1, 'y': 1}, 'right': {'x': 2, 'y': 3}, 'left_path': 'data->[0]',
'right_path': 'data->[2]'},
{'left': {'x': 1, 'y': 1}, 'right': {'x': 2, 'y': 3}, 'left_path': 'data->[0]',
'right_path': 'data->[2]'}
],
'list:add': [
{'left': '__NON_EXIST__', 'right': {'x': 150, 'y': 150}, 'left_path': '', 'right_path': 'data->[0]'}
],
'list:remove': [
{'left': {'x': 100, 'y': 100}, 'right': '__NON_EXIST__', 'left_path': 'data->[2]', 'right_path': ''}
],
'operator:l2distance': [
{'left': {'x': 1, 'y': 1}, 'right': {'x': 2, 'y': 3}, 'left_path': 'data->[0]',
'right_path': 'data->[2]', 'distance': 2.23606797749979, 'distance_threshold': 10,
'pass': True},
{'left': {'x': 10, 'y': 10}, 'right': {'x': 10, 'y': 11}, 'left_path': 'data->[1]',
'right_path': 'data->[1]', 'distance': 1.0, 'distance_threshold': 10,
'pass': True}
],
'value_changes': [
{'left': 1, 'right': 2, 'left_path': 'data->[0]->x', 'right_path': 'data->[2]->x', 'old': 1, 'new': 2},
{'left': 1, 'right': 3, 'left_path': 'data->[0]->y', 'right_path': 'data->[2]->y', 'old': 1, 'new': 3},
{'left': 10, 'right': 11, 'left_path': 'data->[1]->y', 'right_path': 'data->[1]->y', 'old': 10, 'new': 11}
]
}
assert ycm.to_dict() == expected
As you can see jycm report addition and remove for points {'x': 150, 'y': 150} and {'x': 100, 'y': 100} for their
distances are too far (more than 10) and value-change for the other two points.
P.S. RENDERER DEMO
