Deep property accessors for JavaScript objects.
npm install key-path> Deep property accessors for JavaScript objects.
Originally taken from Polymer observe-js
``sh`
$ npm install --save key-path
`js
var KeyPath = require('key-path');
var kp = KeyPath.get(['identifier', 1, 'string with space']);
// OR
var kp = KeyPath.get("identifier[1]['string with space']");
var obj = {
identifier: [
'some value',
{
'string with space': 'you got me!'
}
]
}
assert kp.getValueFrom(obj) === 'you got me!'
kp.setValueFrom(obj, 'something else');
assert obj.identifier[1]['string with space'] === 'something else'
`
A path is an ECMAScript expression consisting only of identifiers (myVal), member accesses (foo.bar) and key lookup with literal values (arr[0] obj['str-value'].bar.baz).
KeyPath.get('foo.bar.baz') returns a KeyPath object which represents the path. KeyPath objects have the following API:
`JavaScript
{
// Returns the current of the path from the provided object. If eval() is available, a compiled getter will be
// used for better performance.
getValueFrom: function(obj) { }
// Attempts to set the value of the path from the provided object. Returns true IFF the path was reachable and
// set.
setValueFrom: function(obj, newValue) { }
}
`
KeyPath objects are interned (e.g., assert(KeyPath.get('foo.bar.baz') === KeyPath.get('foo.bar.baz'));) and are used internally to avoid excessive parsing of path strings. Observers which take path strings as arguments will also accept Path objects.
KeyPath.getAll can be used for making a variadic call to KeyPath.get. That is, if you call it with a few paths (e.g., KeyPath.getAll('foo.bar1', 'foo.bar2')) you will receive an array of KeyPath objects.
`shrun tests
$ npm test
Copyright © 2015 Amit Portnoy.
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[npm-image]: https://img.shields.io/npm/v/key-path.svg?style=flat
[npm-url]: https://npmjs.org/package/key-path
[travis-image]: https://travis-ci.org/CardForest/key-path.svg?branch=master
[travis-url]: https://travis-ci.org/CardForest/key-path
[daviddm-image]: https://david-dm.org/CardForest/key-path.svg?theme=shields.io
[daviddm-url]: https://david-dm.org/CardForest/key-path