underscore-keypath

key-path mechanism extensions for underscore (mixin).

underscore-keypath let you access JavaScript objects and arrays with keypath easily.

1var foo = {
2  bar : {
3    name : "Cool!"
4  },
5  scores : [55, 27, 100, 33]
6};
7
8_(foo).valueForKeyPath("bar.name");           // --> "Cool!"
9_(foo).setValueForKeyPath("bar.name", "BAR"); // --> sets foo.bar.name as "BAR"
10_(foo).valueForKeyPath("scores.@max");        // --> 100

Install

NodeJS

$ npm install underscore-keypath

1var _ = require("underscore-keypath");

or you may want to use origianl underscore:

1var _ = require("underscore");
2require("underscore-keypath"); // it will extend original underscore

in this case, please install "underscore" first.

$ npm install underscore
$ npm install underscore-keypath

Otherwise, underscore-keypath extends separated underscore in sandbox.

Meteor

$ meteor add jeeeyul:underscore-keypath

Front-end

$ bower install underscore-keypath

Or just download underscore-keypath.js manually.

Examples

1var list = [{
2  name : "foo",
3  info : {
4    favoriteColor : "red",
5    age : 20
6  }
7},{
8  name : "bar",
9  info : {
10    favoriteColor : "green",
11    age : 17
12  }
13},{
14  name : "zar",
15  info : {
16    favoriteColor : "red",
17    age : 34
18  }
19}];
20
21_(list).pluckByKeyPath("info.age");           // --> [20, 17, 34]
22_(list).sortByKeyPath("info.age");            // --> [{name:"bar", ..}, {name:"foo", ..}, {name:"zar", ..}]
23_(list).groupByKeyPath("info.favoriteColor"); // --> {red:2, green:1}
24

See API Document