functional-extract

Quickly extracts property values nested deep inside an object.

Install and use under Node:

npm install functional-extract --save
var fe = require('functional-extract');

Install and use in browser using bower:

bower install functional-extract
<script src="bower_components/functional-extract/fe.js"></script>
// attaches as window.fe object

Example

Imagine we need to extract first name, age and give a default gender value for the following object:

var joe = {
  name: {
    first: 'joe',
    last: 'smith'
  },
  age: 20
};

Using functional-extract and functional-pipeline we can do this quickly

var fp = require('functional-pipeline');
var fe = require('functional-extract');
var simple = {
  name: fp('name', 'first'),
  age: fp('age'),
  gender: 'male'
};
// simple is an object
// { name: [Function], age: [Function], gender: 'male' }
var result = fe(simple, joe);
// result is
// { name: 'joe', age: 20, gender: 'male' }

You can use other libraries to extract a property from an object, for example lodash/get, as long as it returns an object that will receive the actual object reference.

function _get(path) {
  return function (obj) {
    return _.get(obj, path);
  };
}
var simple = {
  name: _get('name.first'),
  age: _get('age')
};
var result = fe(simple, joe);
// result is
// { name: 'joe', age: 20 }

For more examples, see my blog post Deep picking

Small print

License: MIT - do anything with the code, but don't blame me if it does not work.

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Support: if you find any problems with this module, email / tweet / open issue on Github

MIT License

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.