甘艺伟 082d4d53ac no message 2 недель назад
..
.github 082d4d53ac no message 2 недель назад
lib 082d4d53ac no message 2 недель назад
.jscsrc 082d4d53ac no message 2 недель назад
.jshintrc 082d4d53ac no message 2 недель назад
.travis.yml 082d4d53ac no message 2 недель назад
LICENSE 082d4d53ac no message 2 недель назад
README.md 082d4d53ac no message 2 недель назад
example.js 082d4d53ac no message 2 недель назад
package.json 082d4d53ac no message 2 недель назад

README.md

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'));