New Features

• Added the disable-upgrade feature from Polymer 1 as a mixin
• Add _shouldPropertiesChange method to customize when _propertiesChanged is called
  • This method gets the current, pending, and old property values and returns a boolean. If _shouldPropertiesChange returns true, _propertiesChanged is called.

Meaningful Changes

• <style include> values are now deduplicated to prevent unexpected conflicts
• static get template() {return null} can now be used to disable inheriting a template from a superclass
• tap gesture now correctly handles the disabled attribute
• click will no longer be squelched if a <label for> is tapped
• Support bindings to capitalized attributes:
  • Bindings of the form <svg viewBox="[[value]]">

Raw Notes

• Use function instead of Set (commit)

• [ci skip] Fix typo (commit)

• Fix test in shady DOM (commit)

• Deduplicate style includes (commit)

• use a clearer test for shadowRoot (commit)

• Returning null in template should nullify parent template (commit)

• [ci skip] Add clarifying comment (commit)

• Correct the JSBin version (commit)

• Put attribute capitalization fix in property-effects (commit)

• Add note about pre v3 releases (commit)

• Add note for npm package (commit)

• Add iron-component-page dev-dependency (commit)

• Update several gulp dependencies (commit)

• Update dom5 to 3.0.0 (commit)

• Update Google Closure Compiler version and fix cast (commit)

• Update types (commit)

• Fix several issues in the documentation of dom-* elements (commit)

• Handle disabled attribute correctly for tap gesture (commit)

• add test case for nested label (commit)

• Add docs and cleanup matchingLabels (commit)

• Add tests (commit)

• update types (commit)

• fix tests and add dependency import (commit)

• fix typings (commit)

• Ensure DisableUpgradeMixin extends PropertiesMixin (commit)

• Format comment and remove deduping mixin (commit)

• update types (commit)

• update types (commit)

• Add mixin to automatically detect capitalized HTML attributes (commit)

• Add instructions for locally viewing the source documentation (commit)

• Simplify condition checking in stylesFromModule function (commit)

• Bump type generator and generate new typings. (#5119) (commit)

• dispatchEvent returns boolean (#5117) (commit)

• Update types (commit)

• Fix license links (commit)

• Fix issue with not genering the Templatizer docs (commit)

• Bump TS type generator to pick up transitive mixin handling. (commit)

• Remove unnecessary mutableData property from MutableData mixin (commit)

• Update types (commit)

• Add note to updateStyles regarding updates to CSS mixins (commit)

• Avoid timing issues with polyfilled Promise (commit)

• Revert use of async/await due to lack of build/serve support. (commit)

• Revert types. (commit)

• Update eslint parserOptions to es2017 for async/await support. (commit)

• Use stronger check for PropertyEffects clients. Fixes #5017 (commit)

• Remove unneeded file (commit)

• [PropertiesChanged]: allow old data to be gc'd after _propertiesChanged (commit)

• Update package-lock.json (commit)

• Make Travis update-types failure style the same as the elements. (commit)

• Bump TypeScript generator version. (commit)

• Make EventApi.path EventTarget type non-nullable. (commit)

• Lint and type fixes (commit)

• [PropertiesChanged]: adds _shouldPropertiesChange (commit)

• Update docs: templatize() cannot be called multiple times (commit)

• [ci skip] update changelog (commit)

• Update types. (commit)

• Fix JSDoc example formatting (commit)

• Use latest webcomponents polyfill bundle (commit)

• Fix label tap by checking matched label pairs (commit)

• Defer creation related work via disable-upgrade (commit)

• lint fixes (commit)

• Adds Polymer.DisableUpgradeMixin (commit)