vasille/lib/value/pointer.js

The first Developer eXperience Orientated front-end framework (core library).

import { IValue } from "../core/ivalue.js";
import { Reference } from "./reference.js";
/**
 * r/w pointer to a value
 * @class Pointer
 * @extends IValue
 */
export class Pointer extends IValue {
    /**
     * Constructs a notifiable bind to a value
     * @param value {IValue} is initial valu
     */
    constructor(value) {
        super();
        this.handler = (v) => {
            this.reference.$ = v;
        };
        this.target = value;
        this.reference = new Reference(value.$);
        value.on(this.handler);
    }
    get $() {
        return this.reference.$;
    }
    set $(v) {
        this.target?.off(this.handler);
        this.target = null;
        this.reference.$ = v;
    }
    get $$() {
        return this.reference.$;
    }
    set $$(v) {
        /* istanbul ignore else */
        if (this.target !== v) {
            this.disconnectTarget();
        }
        if (v instanceof IValue) {
            this.target = v;
            this.target.on(this.handler);
            this.reference.$ = v.$;
        }
        else {
            this.$ = v;
        }
    }
    on(handler) {
        this.reference.on(handler);
    }
    off(handler) {
        this.reference.off(handler);
    }
    destroy() {
        this.target?.off(this.handler);
        this.reference.destroy();
        super.destroy();
    }
    disconnectTarget() {
        this.target?.off(this.handler);
    }
}
export class OwningPointer extends Pointer {
    destroy() {
        this.target?.destroy();
        super.destroy();
    }
    disconnectTarget() {
        this.target?.destroy();
    }
}