[](https://www.webcomponents.org/element/SherbyElements/sherby-nested-property) [](https://travis-ci.org/SherbyElements/sherby-nested-property) ## sherby-nested-property A **Polymer 3** mixin to add functions to obtain a nested property of an object. Instead of using multiples `&&` to ensure that an object have a nested value, you could use the `NestedPropertyMixin` to obtain the value if defined. ```javascript const data = { webcomponents: { 'polymer-3': { npm: true, modules: true, }, 'polymer-2': { bower: true, }, }, }; let npm; if (data && data.webcomponents && data.webcomponents['polymer-3'] && data.webcomponents['polymer-3'].npm) { npm = data.webcomponents['polymer-3'].npm; } // eslint-disable-next-line no-console console.log(npm); ``` ```javascript const data = { webcomponents: { 'polymer-3': { npm: true, modules: true, }, 'polymer-2': { bower: true, }, }, }; const npm = this.getNestedPropertyOf(data, 'webcomponents.polymer-3.npm'); // eslint-disable-next-line no-console console.log(npm); ``` ## Installation As Polymer 3 use npm, you must use it to install this component: ```bash npm install @sherby/sherby--nested-property ``` For the **Polymer 2** version, use the `SherbyElements/sherby-nested-property#^v1.0.0` inside your bower.json file. ```bash bower install SherbyElements/sherby-nested-property --save ``` ## Use Inmport the mixin ```javascript import { PolymerElement } from '@polymer/polymer/polymer-element.js'; import { SherbyNestedPropertyMixin } from '@sherby/sherby-nested-property/sherby-nested-property-mixin.js'; /* eslint-disable no-unused-vars */ /** * @customElement * @polymer * @extends {PolymerElement} * @appliesMixin SherbyNestedPropertyMixin */ class Polymer3Element extends SherbyNestedPropertyMixin(PolymerElement) { // Use the getNestedProperty or the getNestedPropertyOf functions computeData(data) { const npm = this.getNestedPropertyOf(data, 'webcomponents.polymer-3.npm'); // eslint-disable-next-line no-console console.log(npm); } } ```