unfatten

Simple schema-based object filtering

Requires node v4 or above

npm install unfatten

• usage
• api

---

usage

import unfatten from 'unfatten'

const fatObj = {
  a: 1,
  b: 2,
  c: 3,
  d: {
    a: 2,
    b: [3, 'a', {hi: 'hello', bye: 'goodbye'}],
    c: 4,
    d: 5,
    e: [6, 7, 8]
  }
}

const filter = {
  a: true,
  c: true,
  d: {
    b: [true, false, {hi: true}],
    c: true,
    e: {
      1: true
    }
  }
}

const thinObj = unfatten(fatObj, filter)

console.log(thinObj)
/*
{
  a: 1,
  c: 3,
  d: {
    b: [3, {hi: 'hello'}],
    c: 4,
    e: [7]
  }
}
*/

api

unfatten(data, schema)

Filters an object to given filters.

data is a non-null object that will be filtered

schema is the schema that we use to filter the object with. See the example in the usage above.

Properties of the object are 1:1 mappings against the source object. If a value encountered during filtering is undefined, then the filter will throw an error.

The schema's value's function is dependent on the source object property's value:

For primitive values (null, string, number):

• true will include the value in the filtered object.
• false will not include the value in the filtered object. If not part of an object, it will be undefined.
• Everything else will throw an error.

For arrays ([]):

• true will include the value in the filtered object.
• false will not include the value in the filtered object. If not part of an object, it will be undefined.
• An array will include a filtered array, with these rules:
  • Given array must have valid unfatten schemas, for recursive filtering.
  • The array will filter the source object array by index, a 1:1 mapping. For example, in array [1, 2, 3, 4], [true, false, true] will filter the array to [1, 3].
• An object will include a filtered array, with these rules:
  • Given object's properties must be valid unfatten schemas, for recursive filtering.
  • The object will filter the source object array by index, defined by the object's properties. For example, in array [1, 2, 3, 4], {0: true, 1: false, 2: true} will filter the array to [1, 3].
• Everything else will throw an error.

For objects ({}):

• true will include the value in the filtered object.
• false will not include the value in the filtered object. If not part of an object, it will be undefined.
• An object will recurse the filter on the source object's property, using the given object as the unfatten schema.
• Everything else will throw an error.