Monocle-api-props NPM

Monocle API Props

Uses the Monocle API "props" syntax to determine if an object or array contains the specified properties.

Basic Usage

// Require this library
var MonocleApiProps = require('monocle-api-props');

// Create an instance with an array or object we want to check
var props = new MonocleApiProps(something);

// Check if deeply nested properties exist using Monocle API's path syntax
props.has('someProp.someNestedProp'); // returns true or false if the path exists

Syntax

.: a nested property, e.g. a.b will be found within the object { a: { b: 1 } }
@: a property within each object in an array, e.g. a@b will be find `{ a: { b: 1 }, { b: 2 } }

Advanced Example

// Sample object
var users = {
    total: 3,
    filters: {
        minAge: 20,
        maxAge: 40
    },
    items: [
        {
            name: 'Alice',
            age: 27,
            primaryPhoto: {
                url: 'http://...'
            }
        },
        {
            name: 'Jane',
            age: 32,
            primaryPhoto: {
                url: 'http://...'
            }
        },
        {
            name: 'Ed',
            age: 29,
            primaryPhoto: {
                url: 'http://...'
            }
        }
    ]
};

// Create an instance with the users data
var props = new MonocleApiProps(users);

// Basic top-level property access
props.has('total');             // returns true because users has a "total" property
props.has('filters');           // returns true because users has a "filters" property
props.has('foo');               // returns false because users does not have a "foo" property

// Nested properties use a "." separator
props.has('filters.minAge');    // returns true because users.filters has a "minAge" property
props.has('filters.maxAge');    // returns true because users.filters has a "maxAge" property
props.has('filters.derp');      // returns false because users.filters does not have a "derp" property

// Reach into arrays using an "@" separator to ensure they all contain the specified property
props.has('items@name');        // returns true because each object in the items array has a "name" property
props.has('items@age');         // returns true because each object in the items array has an "age" property
props.has('items@flerp');       // returns false because at least one object in the items array did not have a "flerp" property

// Mix and match "@" and "." as necessary to drill deeper
props.has('items@primaryPhoto.url'); // returns true because each object in the "items" array has a "primaryPhoto" object with a "url" property.
props.has('items@primaryPhoto.url'); // returns true because each object in the "items" array has a "primaryPhoto" object with a "url" property.

Files and Directory Structure

The following describes the various files in this repo and the directory structure.

Note: Files and directories prefixed by * are auto-generated and excluded from the repository via .gitignore.

.
├── Gruntfile.js            # grunt task configuration
├── README.md               # this file
├── *docs                   # autogenerated documentation
│   └── *index.html         # each JS file in `./lib` has a corresponding HTML file for documentation
├── lib                     # all code for this library will be placed here
│   └── index.js            # main entry point for your npm package
├── *node_modules           # all dependencies will be installed here by npm
├── package.json            # description of this package for npm, including dependency lists
└── test                    # unit test configuration, reports, and specs
    ├── *coverage.html      # code coverage report
    ├── lib                 # specs go here, preferably with a 1:1 mapping to code in `./lib`
    │   └── index_test.js   # example spec for `./lib/index.js`
    ├── mocha.opts          # runtime options for mocha
    └── test_runner.js      # configures mocha environment (e.g. chai, sinon, etc.)