@surface/custom-element/internal/aot/statements/inject-statement.js

Provides support of directives and data binding on custom elements.

import { CancellationTokenSource } from "@surface/core";
import { scheduler } from "../../singletons.js";
import TemplateMetadata from "../metadata/template-metadata.js";
import observe from "../observe.js";
export default class InjectStatement {
    constructor(context) {
        this.context = context;
        this.cancellationTokenSource = new CancellationTokenSource();
        this.disposed = false;
        this.key = "";
        this.task = () => {
            this.disposeCurrentInjection();
            this.key = this.context.key(this.context.scope);
            const injectionContext = {
                directives: this.context.directives,
                factory: this.context.factory,
                host: this.context.host,
                parent: this.context.parent,
                pattern: this.context.value,
                scope: this.context.scope,
            };
            this.metadata.injections.set(this.key, injectionContext);
            const action = this.metadata.placeholders.get(this.key);
            if (action) {
                action(injectionContext);
            }
        };
        this.metadata = TemplateMetadata.from(context.parent);
        const listener = () => void scheduler.enqueue(this.task, "normal", this.cancellationTokenSource.token);
        this.keySubscription = observe(context.scope, context.observables[0], listener, true);
        this.subscription = observe(context.scope, context.observables[1], listener, true);
        this.task();
    }
    disposeCurrentInjection() {
        if (this.key) {
            this.metadata.injections.delete(this.key);
            this.metadata.defaults.get(this.key)?.();
        }
    }
    dispose() {
        if (!this.disposed) {
            this.cancellationTokenSource.cancel();
            this.disposeCurrentInjection();
            this.keySubscription.unsubscribe();
            this.subscription.unsubscribe();
            this.disposed = true;
        }
    }
}