@mic-rexjs/usecases/es/classes/EntityStore/index.js

Usecases of Clean Architecture

export class EntityStore {
    #watchers = [];
    value;
    constructor(initialEntity, options = {}) {
        const { onChange } = options;
        this.value = initialEntity;
        if (!onChange) {
            return;
        }
        this.watch(onChange);
    }
    setValue(value) {
        const { value: oldValue } = this;
        this.value = value;
        if (oldValue === value) {
            return;
        }
        for (const watcher of this.#watchers) {
            watcher(value, oldValue);
        }
    }
    unwatch(watcher) {
        const watchers = this.#watchers;
        const index = watchers.indexOf(watcher);
        if (index === -1) {
            return;
        }
        watchers.splice(index, 1);
    }
    watch(watcher) {
        this.#watchers.push(watcher);
    }
}