object-getvalue

object-getvalue (npm-link)

Get the Object's property directly including nested properties. It supports the default return value and hasOwnProperty check.

Runtime Error occurs when any key in the sequence is undefined while getting the Object's nested property value.

person.address.location.current.city

To Avoid that, it's best practise to check for each property on object in sequence

if (person.address &&
    person.address.location &&
    person.address.location.current &&
    person.address.location.current.city) {
 
    // var city = person.address.location.current.city
 
}

This package helps you in directly getting the nested property value from the Object

getValue(person, 'address.location.current.city') //=> 'Bangalore'

You can use it to avoid ternary operation while fetching the Object value and assigning that to a variable without worrying about any run-time error.

// Traditional way
var city = person.address.location.current.city ? person.address.location.current.city : 'Bangalore';
 
// Cleaner & Safe way - using getValue()
var city = getValue(person, 'address.location.current.city', 'Bangalore');

Installation

npm install object-getvalue --save

Usage

Arguments

1. object (Object) The object to query
2. property (String) Simple or Nested property
3. (Optional) defaultValue (any) The value returned ONLY if property value resolves to undefined
4. (Optional) hasOwnProperty (bool - default : false) Checks for the property only on the current object but NOT on Prototype/Parent.

Example

var getValue = require('object-getvalue');
OR
import getValue from 'object-getvalue';
 
var Person = function() {
    this.name = 'No name defined yet';
    this.age = 25;
    this.address = {
        city: 'Default - New Delhi',
        country: 'Default - India'
    };
};
 
var Employee = function() {
    this.name = 'Ravi Roshan';
    this.company = 'XYZ Consulting';
    this.empId = 12345;
    this.address = {
        city: 'Bangalore'
    };
    this.details = {
        role: 'Developer',
        designation: 'Consultant',
        domain: 'e-commerce'
    };
    this.friends = [{
        name: 'Siddhant',
        age: 27
    }, {
        name: 'Harsh',
        age: 26
    }, {
        name: 'Argha',
        age: 28
    }];
};
 
// Inherit the Person Object
Employee.prototype = new Person();
 
// Create an instance of Employee
var emp1 = new Employee();
 
// Check for property on Current Object
getValue(emp1, 'name') //=> 'Ravi Roshan'
getValue(emp1, 'details.domain') //=> 'e-commerce'
getValue(emp1, 'details.language.primary') //=> undefined
 
// Check for property on Prototype Object'
getValue(emp1, 'age') //=> 25 [Getting from prototype Person Object]
getValue(emp1, 'address.area.pincode') //=> undefined
 
// Check for property on Current Object - with Default Return
getValue(emp1, 'salary', 9999) //=> 9999
getValue(emp1, 'salary', 'Salary not found') //=> 'Salary not found'
getValue(emp1, 'name', 'John') //=> 'Ravi Roshan' [name doesn't resolve to undefined so defaultReturn is not considered]
 
// Check for property ONLY on Current Object
getValue(emp1, 'age', 'Age not found', true) //=> 'Age not found'
 
// Check for property on Current OR Prototype Object
getValue(emp1, 'age', 'Age not found', false) //=> 25
 
// Check for the name property on Friends [array] on Emp [object]
getValue(emp1, 'friends[1].name') //=> 'Harsh'
 

License

MIT