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Custom Elements

Custom elements is a feature that, until recently, was developed as monkeypatches onto various specifications. To help implementers have a consolidated view of how custom elements change the DOM Standard, we have a few resources.

First, there is a rendered HTML diff containing all the changes related to custom elements.

Second, we provide this listing of affected sections:

• Mutation algorithms: in particular insert and remove
• The clone algorithm, to handle elements specifically
• Interface Document:
  • the createElement and createElementNS IDL definitions and algorithms, and the addition of the ElementCreationOptions dictionary.
  • Modifications to the adopt algorithm
• Interface Element:
  • The "custom element state" concept and related definitions
  • The "create an element" algorithm
  • Modifications to changing, appending, removing, and replacing attributes.
  • The attachShadow() method has a provision for custom elements
• Interface DOMImplementation:
  • The createHTMLDocument() method uses "create an element"
• All throughout the spec: [CEReactions] extended attributes are now present