fabmont/safelyRead

A Javascript utility for access nested objects safely.

safely-read

A Javascript utility for access nested objects safely.

Motivation

Let's imagine you're consuming data from an API and some data inside the object given from this API doesn't exist. Your front-end should crash because of that, so using safelyRead will garantee that if the property exist, you'll get it, or transform it, otherwise, will give to you a fallback result. SafelyRead enhance the Lodash's get util by provinding a transform parameter that you can modify the result of the object property.

Instalation

1. Install the last version of safe-read:

   npm install safely-read or yarn add safely-read

2. Import it into your project:

   const safelyRead = require('safely-read');

   // or using ES6+

   import safelyRead from 'safely-read';

Usage

SafelyRead provides a function that accepts four parameters.

1. required {Object}: The object you want to go through;
2. required {Array<String>}: An array of paths that each position is an element of your object;
3. required {Any}: The fallback result, if anything go wrong with the path it will return instead;
4. optional {Function}: A function that will be triggered if the path exists.

Imagine that you have declared an object:

const user = {
  name: 'Bruce Wayne',
  age: 30,
  hero: 'Batman',
};

And for some reason you want to access the age property of the object above by using safelyRead.

safelyRead(user, ['age'], 'Age not found.', (age) => `${age} years old`);

If user.age exists, so the fourth parameter will be triggered (returning '30 years old'). NOTE: if you didn't pass the transform function and user.age exist, so it will return '30' to you.

What if safelyRead can't access the property I want?

safelyRead(user, ['car'], 'This property doesn't exist.');

The user object doesn't contain any car property, so safelyRead will return the third parameter (This property doesn't exist.).