The Polymer library makes it easy to create your own web components. Give your element some markup and properties, and then use it on a site. Polymer provides features like dynamic templates and data binding to reduce the amount of boilerplate you need to write
This html multi combo wraps any select component that takes an items array. Important functionality for combos includes: 1. Given a 'url' it will fetch the data for you (from the server) and insert it into the 'items' array of the combo in the slot. 2. If multiselect is specified it will use the combo box in the slot to allow multiple selections and put them into pills below the combo input.