dot-filter

A node.js module to filter the fields of an object using the dot notation.

The goal of dot-filter is to provide an easy way to downsize your fat javascript objects.

Install

Install dot-filter using npm

$ npm install dot-filter --save

Usage

Import the library with require and simply pass to it your object and the array of fields that you want to keep:

var dotFilter = require('dot-filter');
 
var obj =  {a: {b: {c: 'd'}, e: {f: 'g'}};
var fields = ["a.b.c"];
dotFilter(obj, fields);
//=> {a: {b: {c: 'd'}}}

Examples

Let's suppose that we have a full user object:

var user = {
    name: "John",
    password: "$2a$04$/oskCCAGHJpqcd3Uwn/gKex1GCxz/XYQ5uK0T20BY1zPVY8IhNHZG",
    email: "[e-mail]",
    phones: [
        { personal: "[phone]" },
        { work: "[phone]" }
    ],
    address: {
        street: "1600 Amphitheatre Pkwy",
        postalCode: "94043",
        city: "Mountain View",
        region: "CA",
        country: "USA"
    }
};

but we want to provide just basic informations, such as name and email.

We can filter out the rest, specifying the fields that we want to keep:

var fields = [ "name", "email" ];
var filteredUser = dotFilter(user, fields);

this will produce a lighter object, with only the required informations

// filteredUser
{
    name: "John",
    email: "[e-mail]"
};

Dot notation

We can dive into inner objects using the dot notation.

Simple object

Using the previous user object we can keep only part of the address, such as the country:

var fields = [ "name", "address.country" ];
var filteredUser = dotFilter(user, fields);

the result will be:

// filteredUser
{
    name: "John",
    address: {
        country: "USA"
    }
};

Array

In case of arrays, only object with the matching property will be returned:

var fields = [ "name", "phones.work" ];
var filteredUser = dotFilter(user, fields);

the result will be:

// filteredUser
{
    name: "John",
    phones: [
        { work: "[phone]" }
    ]
};

Contributing

Pull requests and stars are always welcome!

If you discover any bugs or you have a feature requests, please create an issue.

Author

Enrico Candino

• github/enrichman
• twitter/enrichmann

License

Copyright © 2015 Enrico Candino

Released under the MIT license.