vasille/lib/models/map-model.js

The same framework which is designed to build bulletproof frontends (core library).

import { Listener } from "./listener.js";
/**
 * A `Map` based memory
 * @class MapModel
 * @extends Map
 * @implements ListenableModel
 */
export class MapModel extends Map {
    listener;
    /**
     * Constructs a map model
     * @param map {[*, *][]} input data
     * @param ctx lifetime context
     */
    constructor(map, ctx) {
        super();
        this.listener = new Listener();
        map?.forEach(([key, value]) => {
            super.set(key, value);
        });
        ctx?.bind(this);
    }
    /**
     * Calls `Map.clear` and notify about changes
     */
    clear() {
        this.forEach((value, key) => {
            this.listener.emitRemoved(key, value);
        });
        super.clear();
    }
    /**
     * Calls `Map.delete` and notify abut changes
     * @param key {*} key
     * @return {boolean} true if removed something, otherwise false
     */
    delete(key) {
        const tmp = super.get(key);
        /* istanbul ignore else */
        if (tmp) {
            this.listener.emitRemoved(key, tmp);
        }
        return super.delete(key);
    }
    /**
     * Calls `Map.set` and notify abut changes
     * @param key {*} key
     * @param value {*} value
     * @return {MapModel} a pointer to this
     */
    set(key, value) {
        const tmp = super.get(key);
        if (tmp) {
            this.listener.emitRemoved(key, tmp);
        }
        super.set(key, value);
        this.listener.emitAdded(key, value);
        return this;
    }
    destroy() {
        this.clear();
    }
}