Object Mapper

For those not so common situations where you just want to know the composition of a complex object to analyze and probably recompose such object.

Install

npm install @universal-packages/object-mapper

Global methods

mapObject(subject: Object, [options, callback)

Will traverse an object recursively and will generate a record for every property in it describing it, or if a property is an object will map it as a object map as well. If the object mapper finds a loop in the hierarchy it will reference the previously processed object map for the object that creates the loop.

import { mapObject } from '@universal-packages/object-mapper'

const result = mapObject({ hola: 'hello' })

// > {
// >   id: 0,
// >   level: 0,
// >   properties: { hola: { descriptor: undefined, propertyKey: 'hola', level: 0, type: 'string', value: 'hello' } },
// >   type: 'object'
// > }

Options

• ignoreInaccessible boolean default: true Some properties in the prototype chain can't be accessed in any way, you can get an error of this event or just ignore those properties

• ignoreLevelsBeyondMaxDepth boolean If a property is in a level beyond the max you can ignore it or get an error of the event.

• keyInspector 'simple' | 'prototypeChain' default: simple A simple key inspector will getOwnPropertyNames to get properties from the object, or you can opt to get all properties going all up the prototype chain, useful to get properties inherited in classes.

• maxDepth number Max level the recursive traversal can reach

• propertyFilter

  • include RegExp | string[] include only matching property names.

    Copy

    import { mapObject } from '@universal-packages/object-mapper'
    
    const options = {
      propertyFilter: { include: ['property1', 'property3'] }
    }
    
    const result = mapObject({ property1: '1', property2: '2', property3: '3' }, options)
    
    console.log(result)
    
    // > { properties: { property1: { ... }, property3: { ... } } }

  • exclude RegExp | string[]

    Copy

    import { mapObject } from '@universal-packages/object-mapper'
    
    const options = {
      propertyFilter: { exclude: ['property1', 'property3'] }
    }
    
    const result = mapObject({ property1: '1', property2: '2', property3: '3' }, options)
    
    console.log(result)
    
    // > { properties: { property2: { ... } } }

Callback

Use a callback for every value visited to use it or modify it in any way in the original object.

import { mapObject } from '@universal-packages/object-mapper'

const result = mapObject({ hola: 'hello' }, null, (value: any): any => {
  return 'other value post processing it'
})

console.log(result)

//> {
//>   id: 0,
//>   level: 0,
//>   properties: { hola: { descriptor: undefined, propertyKey: 'hola', level: 0, type: 'string', value: 'other value post processing it' } },
//>   type: 'object'
//> }

Typescript

This library is developed in TypeScript and shipped fully typed.

Contributing

The development of this library happens in the open on GitHub, and we are grateful to the community for contributing bugfixes and improvements. Read below to learn how you can take part in improving this library.

• Code of Conduct
• Contributing Guide

License

MIT licensed.