object-match

match selectors in an object

usage

Let's say you have an object that looks like this:

var obj = {
  animals: {
    ostrich: {size: 4},
    'kangaroo rat': {size: 3},
    owl: {size: 2},
    'blue whale': {size: 80},
    megalodon: {size: 100}
  }
}

We can't know the keys in advance, but the structure follows a pattern:

'animals.*.size'

We can get the size of all of the animals like so:

var objectMatch = require('object-match')

var sizes = objectMatch('animals.*.size', obj).map(function (match) { return {
  name: match.path[1],
  size: match.value
})
// => [
//  {name: 'ostrich', size: 4},
//  {name: 'kangaroo rat', size: 3},
//  {name: 'owl', size: 2},
//  {name: 'blue whale': size: 80},
//  {name: 'megalodon', size: 100}
// ]

Matching uses dot notation. Wildcards match any key at that level, and work for either objects or arrays (since array elements are accessible by their index).

You can also supply an array of selectors, which are connected with a logical OR:

objectMatch(['animal.ostrich.size', 'animal.owl.size'], obj).length
// => 2

Match objects look like:

{
  path: ['animals','owl','size'],
  key: 'size',
  value: 2,
  parent: obj.animals.owl
}

In jsig notation:

Match: {
  path: Array<String>,
  key: String,
  value: Value,
  parent: Object
}

matchObject is curried. If you don't supply an object, it will return a function with the selectors bound.

function signature

In jsig notation:

matchObject: (selectors: String|Array<String>, obj: Object) => Array<Match>

or curried

matchObject: (selectors: String|Array<String>) => (obj: Object) => Array<Match>

installation

$ npm install match-object

running the tests

From project root:

$ npm install
$ npm test

contributors

jden [email protected]

license

MIT. (c) 2013 Agile Diagnosis [email protected]. See LICENSE.md