@gluonjs/core / src / PropertyConverter
Interface: PropertyConverter<Value>
Type Parameters
Value
Value = unknown
Methods
fromAttribute()?
optionalfromAttribute(value,type?):Value
Converts an attribute string into the JavaScript property value.
Parameters
value
string | null
type?
Returns
Value
toAttribute()?
optionaltoAttribute(value,type?):string|null
Converts a reflected JavaScript property value into an attribute string.
Parameters
value
Value
type?
Returns
string | null
Example
Translate a reflected Custom Element property between attribute text and its declared runtime value:
import {
GluonElement,
defineElement,
exposedRef,
getPublicInstance,
html,
refreshGluonElements,
renderGluonElementForServer,
setGluonRenderDebugHook,
type ComponentErrorBoundary,
type ComponentErrorInfo,
type ComponentEventMap,
type ComponentLifecycleCallback,
type EventDeclaration,
type EventDeclarations,
type GluonElementServerRender,
type GluonRenderCause,
type GluonRenderDebugEvent,
type GluonRenderDebugHook,
type PropertyConverter,
type PropertyDeclaration,
type PropertyDeclarations,
type PropertyDefinition,
type PropertyType,
type SlotDeclaration,
type SlotDeclarations,
type ValueRefTarget,
} from '@gluonjs/core';
type ProductProps = { name: string; quantity: number };
type ProductEvents = { select: { id: string } };
type ProductEventMap = ComponentEventMap<ProductEvents>;
const converter: PropertyConverter<string> = { fromAttribute: (value) => value ?? '', toAttribute: (value) => value };
const nameType: PropertyType = String;
const name: PropertyDeclaration<string> = { type: nameType, converter, required: true };
const quantity: PropertyDefinition<number> = { type: Number, default: 1, reflect: true };
const selectEvent: EventDeclaration<ProductEvents['select']> = { bubbles: true, composed: true };
const mediaSlot: SlotDeclaration = { required: false, fallback: true };
const slots = { media: mediaSlot } satisfies SlotDeclarations<'media'>;
const connected: ComponentLifecycleCallback = () => console.log('connected');
const boundary: ComponentErrorBoundary = (info) => { console.error(info.source); return true; };
class ProductCard extends GluonElement<ProductEvents> {
static override readonly properties = { name, quantity } satisfies PropertyDeclarations<ProductProps>;
static override readonly events = { select: selectEvent } satisfies EventDeclarations<ProductEvents>;
static override readonly slots = slots;
declare name: string;
declare quantity: number;
constructor() {
super();
this.expose({ select: () => this.emit('select', { id: '42' }) });
this.onConnected(connected);
this.onErrorCaptured((info: ComponentErrorInfo) => boundary(info));
}
protected render() { return html`<article>${this.name} × ${this.quantity}</article>`; }
}
defineElement('product-card', ProductCard);
const element = document.createElement('product-card') as ProductCard;
const publicTarget: ValueRefTarget<Readonly<{ select(): void }>> = { value: undefined };
const publicRef = exposedRef<{ select(): void }>(publicTarget);
if (typeof publicRef === 'function') publicRef(element);
getPublicInstance<{ select(): void }>(element)?.select();
const eventMap: Partial<ProductEventMap> = { select: new CustomEvent('select', { detail: { id: '42' } }) };
const server: GluonElementServerRender = renderGluonElementForServer(ProductCard, { name: 'Lamp' });
const hook: GluonRenderDebugHook = (event: GluonRenderDebugEvent) => {
const cause: GluonRenderCause | undefined = event.causes[0];
console.log(event.element.localName, event.duration, cause);
};
const restore = setGluonRenderDebugHook(hook);
refreshGluonElements();
console.log(server.tagName, server.template, eventMap, publicTarget.value);
if (typeof publicRef === 'function') publicRef(undefined);
restore();