clone-deep-circular-references
v2.0.0
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Shallow and recursively (deep) clone JavaScript objects that handles circular references
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clone-deep-circular-references
Shallow object colone and recursively (deep) clone JavaScript objects that handles circular references.
This is a reimplementation of the package clone-deep to allow have circular references; as well, a reimplementation of shallow-clone to make it friendly with webpack.
Install
Install with npm:
$ npm install --save clone-deep-circular-references
Basic usage
In this way you need to call the cloneDeep
or the cloneShallow
function passing as first argument the value to clone.
import { cloneDeep, cloneShallow } from 'clone-deep-circular-references';
let obj = { a: 'b' };
let arr = [obj];
let deepCopy = cloneDeep(arr);
let shallowCopy = cloneShallow(arr);
obj.c = 'd';
shallowCopy.push('hello');
console.log(deepCopy);
//=> [{ a: 'b' }]
console.log(arr);
//=> [{ a: 'b', c: 'd' }]
console.log(shallowCopy);
//=> [{ a: 'b', c: 'd' }, 'hello']
Cloning custom classes
By default, if a no plain object is found, no copy will be created; if you want to change it, you need to specify true as second argument. Note: in this way the class's constructor will not be called (a new object with the same prototype will be created), and then each property will be set.
import { cloneDeep, cloneShallow } from 'clone-deep-circular-references';
class MyClass {
constructor(value) {
this.prop = value;
}
}
let obj = { a: new MyClass('b') };
let deepCopy = cloneDeep(arr);
console.log(obj === deepCopy);
//=> true
console.log(obj.a === deepCopy.a);
//=> true
deepCopy = cloneDeep(arr, true);
console.log(obj === deepCopy);
//=> false
console.log(obj.a === deepCopy.a);
//=> false
let shallowCopy = cloneShallow(arr);
console.log(obj === shallowCopy);
//=> true
console.log(obj.a === shallowCopy.a);
//=> true
shallowCopy = cloneShallow(arr, true);
console.log(obj === shallowCopy);
//=> false
console.log(obj.a === shallowCopy.a);
//=> true
Controlling how custom classes are cloned
If you want to control how how no plain objects are copied you can specify a function as second argument that copy the value; this function receives as first argument the value to clone and as second argument the a Map with the object already cloned.
Note: if inside the cloneDeep
function you want to call the cloneDeep
function you need to pass a third argument the map with the object already cloned.
import { cloneDeep, cloneShallow } from 'clone-deep-circular-references';
class MyClass {
constructor(value) {
this.prop = value;
}
}
let obj = { a: new MyClass('b') };
let deepCopy = cloneDeep(arr, function myCustomClone(value, instancesMap) {
if (value instanceof MyClass) {
return new MyClass(value.prop)
}
return cloneDeep(value, myCustomClone, instancesMap);
});
console.log(obj === deepCopy);
//=> false
console.log(obj.a === deepCopy.a);
//=> false
let shallowCopy = cloneShallow(arr, function myCustomClone(value) {
if (value instanceof MyClass) {
return new MyClass(value.prop)
}
return cloneShallow(value, myCustomClone);
});
console.log(obj === shallowCopy);
//=> false
console.log(obj.a === shallowCopy.a);
//=> true
Handled types
The following types are handled recursively by the cloneDeep
function:
- Plain objects
- No plain objects (see the previous documentation)
- Arrays
- Map
- Set
The other object types are copied using the cloneShallow
function.
The following types are handled by the cloneShallow
function:
- Plain objects
- No plain objects (see the previous documentation)
- Arrays
- Map
- Set
- Date
- RegExp
- Error
The following types are returned without create a copy:
- Symbol
- Promise
- WeakMap
- WeakSet
- Buffer (nodejs)
- ArrayBuffer
- Int8Array
- Uint8Array
- Uint8ClampedArray
- Int16Array
- Uint16Array
- Int32Array
- Uint32Array
- Float32Array
- Float64Array
- undefined
- null
- boolean
- string
- number
- function
- iterator
- any other special JavaScript object
Related projects
You might also be interested in these projects:
- clone-deep: Recursively (deep) clone JavaScript native types, like Object, Array, RegExp, Date as well as primitives. | homepage
- is-plain-object: Returns true if an object was created by the
Object
constructor. | homepage - kind-of: Get the native type of a value. | homepage
- shallow-clone: Creates a shallow clone of any JavaScript value. | homepage
License
MIT