safe-json-parse-and-stringify

Install

npm i safe-json-parse-and-stringify --save

Usage

import { jsonParse, jsonStringify, cloneDeep } from 'safe-json-parse-and-stringify';

Detail

jsonParse(parseStr, defaultValue)

use JSON.parse with try catch，if catch error, return defaultValue。

Params

• {any} parseStr
• {any} defaultValue

Returns

{any}

Examples

input	first param	output
jsonParse('[1,2,3]', [])	string	[1,2,3]
jsonParse([1,2,3],[])	not string	[1,2,3]
jsonParse('{a:1}', {})	string	{}
jsonParse({a:1}, {})	not string	{a:1}
jsonParse("",{})	string	{}
jsonParse("",[])	string	[]
jsonParse("")	string	undefined
jsonParse()	undefined	undefined

jsonStringify

Like JSON.stringify, but doesn't throw on circular references.

Params

Takes the same arguments as JSON.stringify.

var circularObj = {};
circularObj.circularRef = circularObj;
circularObj.list = [ circularObj, circularObj ];
console.log(jsonStringify(circularObj, null, 2));

Output:

{
  "circularRef": "[Circular]",
  "list": [
    "[Circular]",
    "[Circular]"
  ]
}

Details

The fourth argument usually not used

jsonStringify(obj, serializer, indent, decycler)

The first three arguments are the same as to JSON.stringify. The last is an argument that's only used when the object has been seen already.

The default decycler function returns the string '[Circular]'. If, for example, you pass in function(k,v){} (return nothing) then it will prune cycles. If you pass in function(k,v){ return {foo: 'bar'}}, then cyclical objects will always be represented as {"foo":"bar"} in the result.

cloneDeep

Using JSON.parse(JSON.stringify(obj)) for deep clone is unpredictable and not safe.Use cloneDeep instead.

Example

const a = {};
a.a = a;
const b = JSON.parse(JSON.stringify(a));
/*
Uncaught TypeError: Converting circular structure to JSON
    --> starting at object with constructor 'Object'
    --- property 'a' closes the circle
    at JSON.stringify (<anonymous>)
    at <anonymous>:3:27
*/

Details

This method is loosely based on the structured clone algorithm and supports cloning arrays, array buffers, booleans, date objects, maps, numbers, Object objects, regexes, sets, strings, symbols, and typed arrays. The own enumerable properties of arguments objects are cloned as plain objects. An empty object is returned for uncloneable values such as error objects, functions, DOM nodes, and WeakMaps. And it recursively clones value.

Arguments

value (*): The value to recursively clone.

Returns

(*): Returns the deep cloned value.

Example

var objects = [{ 'a': 1 }, { 'b': 2 }];

var deep = cloneDeep(objects);
console.log(deep[0] === objects[0]);
// => false