A module to filter and diff complex nested objects having circular references.
It was implemented to filter out some values from inconveniently nested objects with circular references and then diff them.
It's designed to work both on nodejs and browser without any dependencies.
npm install --save nested-objects-util
const nestedObjectsUtil = require('nested-objects-util');Flatten object by keys composed from own nested properties.
nestedObjectsUtil.flatten({
keyA: {
keyE: [ 'value3', 'value4' ],
keyF: null,
keyD: 'value2',
keyB: {
keyC: 'value'
}
}
});returns:
{
"keyA.keyE.0": "value3",
"keyA.keyE.1": "value4",
"keyA.keyF": null,
"keyA.keyD": "value2",
"keyA.keyB.keyC": "value"
}with sortKeys=true it would return:
{
"keyA.keyB.keyC": "value",
"keyA.keyD": "value2",
"keyA.keyE.0": "value3",
"keyA.keyE.1": "value4",
"keyA.keyF": null
}Unflatten object by keys composed from own nested properties.
nestedObjectsUtil.unflatten({
'keyA.keyB.keyC': 'value',
'keyA.keyD': 'value2'
});returns:
{
"keyA": {
"keyB": {
"keyC": "value"
},
"keyD": "value2"
}
}Access object's nested property.
const nestedObject = {
keyA: {
keyB: {
keyC: 'value'
}
}
};
nestedObjectsUtil.accessProperty('keyA.keyB.keyC', nestedObject);returns:
"value"Discard circular references (to avoid "Converting circular structure to JSON" error).
const a = {
b: 1
};
a.c = a;
nestedObjectsUtil.discardCircular(a)returns:
{
"b": 1,
"c": "~"
}nestedObjectsUtil.filterValue(Object: object, Various | Array: query, Boolean: flattenFlag = false): Object
Filter a nested object by value or values (if array passed). Strict comparison is performed.
const a = {
b: {
c: 'str',
d: 'str2'
},
e: 'str',
f: {
g: {
h: 'str',
i: 'str3'
},
j: 'str4'
},
k: [ 'str', 'str5' ]
};
a.l = a.b;
nestedObjectsUtil.filterValue(a, 'str');returns:
{
"b": {
"c": "str"
},
"e": "str",
"f": {
"g": {
"h": "str"
}
},
"k": [ "str" ]
}or with flattenFlag = true
nestedObjectsUtil.filterValue(a, 'str', true);returns:
{
"b.c": "str",
"e": "str",
"f.g.h": "str",
"k.0": "str"
}On browser with HTML5 download API: stringify, format and download the object.
Else: return stringified text.
const a = {
b: 1,
c: {
d: 2,
e: 2
}
};
a.f = a;
a.g = a.f;
const obj = nestedObjectsUtil.discardCircular(a);
nestedObjectsUtil.downloadStringified(obj);returns:
{
"b": 1,
"c": {
"d": 2,
"e": 2
},
"f": "~",
"g": "~"
}Compare two objects against each other (by JSON.stringify) after discarding circular references, flattening and ordering keys.
const objectA = {
keyA: {
keyB: {
keyC: 'value'
},
keyD: 'value2',
keyE: [ 'value3', 'value4' ]
}
};
objectA.circular = objectA;
const objectB = {
keyA: {
keyE: [ 'value3', 'value4' ],
keyD: 'value2',
keyB: {
keyC: 'value'
}
}
};
objectB.circular = objectB;
nestedObjectsUtil.areObjectsEqual(objectA, objectB);returns:
truenestedObjectsUtil.getObjectsDiff(Object: objectA, Object: objectB, Boolean: sortKeysFlag = false, Boolean: flattenFlag = false): Object
Get the properties which differ between object A and object B and return only those from object B.
const objectA = {
keyA: {
keyB: {
keyC: 'value'
},
keyD: 'value2',
keyE: [ 'value3' ]
}
};
objectA.circular = objectA;
const objectB = {
keyA: {
keyB: {
keyC: 'value'
},
keyD: 'value2_CHANGED',
keyE: [ 'value3_CHANGED' ]
}
};
objectB.circular = objectB;
nestedObjectsUtil.getObjectsDiff(objectA, objectB);returns:
{
"keyA": {
"keyD": "value2_CHANGED",
"keyE": [ "value3_CHANGED" ]
}
}In the browser, NestedObjectsUtil object is exposed either to window or with AMD.
Filter out 'abcd' value from the flattened object and download stringified JSON via HTML5 API with:
const object = NestedObjectsUtil.filterValue(App.SomeHugeObject, 'abcd', true);
NestedObjectsUtil.downloadStringified(object);Discar circular references from the object, then flatten and download it.
let object = NestedObjectsUtil.discardCircular(App.SomeHugeObject);
object = NestedObjectsUtil.flatten(object);
NestedObjectsUtil.downloadStringified(object);npm run test