Best Component Libraries for Gerrit Code Review

The Polymer library provides a set of features for creating custom elements. These features are designed to make it easier and faster to make custom elements that work like standard DOM elements. Similar to standard DOM elements, Polymer elements can be instantiated using a constructor or document creation element, configured using attributes or properties, populated with internal DOM inside each instance, responsive to property and attribute changes, styled with internal defaults or externally, and responsive to methods that manipulate its internal state. Registering an element associates a class with a custom element name. The element provides callbacks to manage its lifecycle. Polymer also lets you declare properties, to integrate your element's property API with the Polymer data system. Shadow DOM provides a local, encapsulated DOM tree for your element. Polymer can automatically create and populate a shadow tree for your element from a DOM template.