Package Exports

undefsafe

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (undefsafe) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

undefsafe

Simple function for retrieving deep object properties without getting "Cannot read property 'X' of undefined"

Can also be used to safely set deep values.

Usage

var object = {
  a: {
    b: {
      c: 1,
      d: [1,2,3],
      e: 'remy'
    }
  }
};

console.log(undefsafe(object, 'a.b.e')); // "remy"
console.log(undefsafe(object, 'a.b.not.found')); // undefined

Demo: https://jsbin.com/eroqame/3/edit?js,console

Setting

var object = {
  a: {
    b: [1,2,3]
  }
};

// modified object
var res = undefsafe(object, 'a.b.0', 10);

console.log(object); // { a: { b: [10, 2, 3] } }
console.log(res); // 1 - previous value

Star rules in paths

As of 1.2.0, undefsafe supports a * in the path if you want to search all of the properties (or array elements) for a particular element.

The function will only return a single result, either the 3rd argument validation value, or the first positive match. For example, the following github data:

const githubData = {
        commits: [{
          modified: [
            "one",
            "two"
          ]
        }, /* ... */ ]
      };

// first modified file found in the first commit
console.log(undefsafe(githubData, 'commits.*.modified.0'));

// returns `two` or undefined if not found
console.log(undefsafe(githubData, 'commits.*.modified.*', 'two'));