A very simple native function for unwinding a collection by a property, like MongoDB's $unwind function.
- This function is immutable. Your original collection doesn't change.
- It works for both primitives and complex values.
- It works for nested arrays, using dot-notation. Like
a.b.c. - It works in ES5-compatible environments, without transpiling.
- Typings available for TypeScript.
$ npm i javascript-unwind --save
const unwind = require('javascript-unwind'); const collection = [ { a: [{ x: 1 }, { x: 2 }], b: 123 }, { a: [{ x: 3 }, { x: 4 }], b: 785, c: 368 }, ]; console.log(unwind(collection, 'a'));
Output:
[ { a: { x: 1 }, b: 123 }, { a: { x: 2 }, b: 123 }, { a: { x: 3 }, b: 785, c: 368 }, { a: { x: 4 }, b: 785, c: 368 } ]
const unwind = require('javascript-unwind'); const collection = [{ name: 'a1', b: [{ name: 'b1', c: [ { name: 'c1' }, { name: 'c2' } ] }, { name: 'b2', c: [ { name: 'c3' }, { name: 'c4' } ] }, ], }, { name: 'a2', b: [{ name: 'b3', c: [ { name: 'c4' }, { name: 'c5' } ] }, { name: 'b4', c: [ { name: 'c6' }, { name: 'c7' } ] } ] } ]; console.log(unwind(collection, 'b.c'));
Output:
[ { "name":"a1", "b":{ "name":"b1", "c":{ "name":"c1" } } }, { "name":"a1", "b":{ "name":"b1", "c":{ "name":"c2" } } }, { "name":"a1", "b":{ "name":"b2", "c":{ "name":"c3" } } }, { "name":"a1", "b":{ "name":"b2", "c":{ "name":"c4" } } }, { "name":"a2", "b":{ "name":"b3", "c":{ "name":"c4" } } }, { "name":"a2", "b":{ "name":"b3", "c":{ "name":"c5" } } }, { "name":"a2", "b":{ "name":"b4", "c":{ "name":"c6" } } }, { "name":"a2", "b":{ "name":"b4", "c":{ "name":"c7" } } } ]
See Issues.