« Changelog History


Polymer v2.0.0-rc.1 Release Notes

Release Date: 2017-03-06 // about 7 years ago

  • 🚀 <!-- the changelog tool broke, so this is ported from https://www.polymer-project.org/2.0/docs/release-notes#v-2-0-0-rc.1 --> The following notable changes have been made since the 2.0 Preview announcement.

    • The config getter on element classes has been replaced by individual properties and observers getters, more closely resembling the 1.x syntax.

      static get properties() {
  return {
    aProp: String,
    bProp: Number
  }
}
static get observers() {
  return [
    '_observeStuff(aProp,bProp)'
  ]
}

    • 🐎 1.x-style dirty checking has been reinstated for better performance. An optional mixin is available for elements to skip dirty checking of objects and arrays, which may be more easy to integrate with some state management systems. For details, see [Using the MutableData mixin](devguide/data-system#mutable-data) in Data system concepts.

    • 💅 Support for dynamically-created custom-style elements has been added.

    • 💅 Support for the external style sheet syntax, <link rel="import" type="css"> has been added. This was deprecated in 1.x, but will be retained until an alternate solution is available for importing unprocessed CSS.

    • New properties rootPath and basePath were added to Polymer.Element to allow authors to configure how URLs are rewritten inside templates. For details, see the [Update URLs in templates](./upgrade#urls-in-templates) in the Upgrade guide.