bootstrap-vue/src/utils/get.js

BootstrapVue, with over 40 plugins and more than 80 custom components, custom directives, and over 300 icons, provides one of the most comprehensive implementations of Bootstrap v4 components and grid system for Vue.js. With extensive and automated WAI-AR

import identity from './identity'
import { isArray, isObject } from './inspect'

const RX_ARRAY_NOTATION = /\[(\d+)]/g

/**
 * Get property defined by dot/array notation in string.
 *
 * @link https://gist.github.com/jeneg/9767afdcca45601ea44930ea03e0febf#gistcomment-1935901
 *
 * @param {Object} obj
 * @param {string|Array} path
 * @param {*} defaultValue (optional)
 * @return {*}
 */
const get = (obj, path, defaultValue = null) => {
  // Handle array of path values
  path = isArray(path) ? path.join('.') : path

  // If no path or no object passed
  if (!path || !isObject(obj)) {
    return defaultValue
  }

  // Handle edge case where user has dot(s) in top-level item field key
  // See https://github.com/bootstrap-vue/bootstrap-vue/issues/2762
  // Switched to `in` operator vs `hasOwnProperty` to handle obj.prototype getters
  // https://github.com/bootstrap-vue/bootstrap-vue/issues/3463
  if (path in obj) {
    return obj[path]
  }

  // Handle string array notation (numeric indices only)
  path = String(path).replace(RX_ARRAY_NOTATION, '.$1')

  const steps = path.split('.').filter(identity)

  // Handle case where someone passes a string of only dots
  if (steps.length === 0) {
    return defaultValue
  }

  // Traverse path in object to find result
  // We use `!=` vs `!==` to test for both `null` and `undefined`
  // Switched to `in` operator vs `hasOwnProperty` to handle obj.prototype getters
  // https://github.com/bootstrap-vue/bootstrap-vue/issues/3463
  return steps.every(step => isObject(obj) && step in obj && (obj = obj[step]) != null)
    ? obj
    : defaultValue
}

export default get