[Custom Elements with Native Element Behaviors] Other considered alternatives #1135
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
alexkeng
reviewed
Aug 20, 2025
| }; | ||
| } | ||
|
|
||
| class CustomButton extends ButtonCustomMixin(HTMLButtonElement) { |
There was a problem hiding this comment.
Suggested change
| class CustomButton extends ButtonCustomMixin(HTMLButtonElement) { | |
| class CustomButton extends ButtonInternalMixin(HTMLElement) { |
ButtonInternalMixin probably is a better name, and the base class should be HTMLElement, not HTMLButtonElement
| this.setAttribute('command', value); | ||
| } | ||
|
|
||
| attributeChangedCallback(name, oldValue, newValue) { |
There was a problem hiding this comment.
this subclass factory should contain all properties/methods from the built-in Button element, not attributeChangedCallback, connectedCallback, etc which are for custom elements
| This alternative proposes a compositional API that allows web developers to opt into specific native behaviors using mixins. These can be added via a method like `elementInternals.addMixin()`, injecting native-like capabilities (e.g., form participation, activation behavior) into custom elements. The approach supports both built-in mixins (provided by the platform) and user-defined ones, enabling flexible combinations of behaviors. | ||
|
|
||
| ```js | ||
| function MyCustomBehaviorMixin(Base) { |
There was a problem hiding this comment.
this is a subclass factory, which is not this alternative is about. This alternative is more about an approach similar to ReactiveController
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Add two considered alternatives for custom elements with native element behaviors.
elementInternals.addMixin()& Compositional Mixins via Subclass Factories