JSON-Reform

A mini NodeJS library that helps you transform JSON objects faster & easier.

Note: This repository is deprecated. Shapeshifter.js is the newer version of Reform.

Installation

Using NPM:

npm install json-reform

In browser:

<script src="reform.js"></script>

Usage

const re = new Reformer(rules [,opts])

Transformation Rules

rules is an object whose keys are names of attributes that you want to transform, values define how these attribute will be transformed.

There are multiple ways to define them:

Rename an attribute

{
  old_name: "new_name"
}

Do something with the value

{
  version: function(v){
      return v+1;
  }
}

Full definition

{
  version: {
      name: 'ver',
      handler: function(v){
          return v+1;
      }
  }
}

One to many relationship

Attribute a will be transformed to a, b and c in the new object.

{
  a: [
      // this produces a
      function(val){
        return val-1;
      },
      
      // this produces b
      "b",
      
      // this produces c
      {
        name: "c",
        handler: function(old_value){
            return old_value + 1;
        }
      }]
}

Many to one relationship

You can access other attribute with the second parameter in the handler function.

{
  x: {
      name: 'z',
      handler: function(x, obj){
          const y = obj.y;
          return x+y;
      }
  }
}

Options

Name	Type	Default	Description
keepUnlisted	Boolean	false	Attributes of origin object that are not listed in schema will be kept.
async	Boolean	false	transform() function will return a Promise. This option must be set to true when you are using any asynchronous function
sequential	Boolean	false	When an array of objects is passed to transform() function, those will be transformed one after another. This may help to avoid overhead when you are sending network requests.

Example

const Reformer = require('json-reform');

const re = new Reformer({
    a: "b",
    c: {
        name: "d",
        handler(val, obj) {
            return val + 1;
        }
    },
    d: [{
        name: "e",
        handler(val) {
            return val + 1;
        }
    }, {
        name: "f",
        handler(val) {
            return val + 2;
        }
    }]
}, {keepUnlisted: true});

const result = re.transform({a: 1, b: 2, c: 3, d: 5, g: 0});
console.log(result);

Output:

{ f: 7, e: 6, d: 4, b: 2, g: 0 }

You can also transform an array of objects

const result = re.transform([{a: 1, b: 2, c: 3, d: 5, g: 0}]);