Has Deep Slides

This module is designed to simplify the painful process of validating the deep properties of an object.

About

var a = {
  b: {
    c: {
      d: {
        e: true
      }
    }
  }
};

In JavaScript, if you try to find a property on an undefined, the script will throw an error.

This sucks.

// this throws your app
var x = a.b.c.d.e.f.g;

The most common way to solve the problem is to have repetitious blocks of if-then code to slowly validate the property path.

This also sucks, but it works.

var x = (a && a.b && a.b.c && a.b.c.d && a.b.c.d.e && a.b.c.d.e.f && a.b.c.d.e.f.g) ? a.b.c.d.e.f.g : 'winning';
console.log(x); // => winning

I'm writing this module to help make it suck less.

var has = require('has-deep');

var x = (has(a, 'b.c.d.e.f.g')) ? a.b.c.d.e.f.g : 'winning';
console.log(x); // => winning

Yeah, the result is the same, but look at how much less validation there is!

has(object, path)

• object - Object This is the source object that you want to validate.
• path - String This is a period-delimited string that is the property path you want to validate.
• Returns the value at the end of the path or undefined if the path doesn't exist.

Example

var has = require('has-deep');

var a = {
  b: {
    c: {
      d: {
        e: 'winning!',
        f: [{
          g: false
        }, {
          g: true
        }]
      }
    }
  }
};

console.log(has(a, 'b.c.d.e.f.g')); // => undefined
console.log(has(a, 'b.c.d.e.f')); // => undefined
console.log(has(a, 'b.c.d.e')); // => "winning!"
console.log(has(a, 'b.c.d')); // => { e: "winning!" }
console.log(has(a, 'b.c.d.f[0].g')); // => false
console.log(has(a, 'b.c.d.f[1].g')); // => true

Install

npm install has-deep

-or-

npm install ben-bradley/has-deep

Test

npm test

-or-

mocha -R spec

Versions

• 1.0.1 - Catch when first property is bracketed
• 1.0.0 - Able to handle dotted properties
• 0.0.6 - Using Object.prototype.toString.call(object) === '[object Object]' for when toString() is overwritten =(
• 0.0.4 - Providing a non-Object variabl for evaluation will return undefined instead of Throwing
• 0.0.3 - Refactored lib to be more functional, modified deep-array valitaion to detect falsey values, added comments
• 0.0.2 - Added deep-array validation
• 0.0.1 - Inital commit