ItemCache.js

ItemCache.js

// Very simple item cache (easily add .flush/dump and/or .delete functions if needed)

class ItemCache {
    constructor({ get, init }){
        this._items = {}
        this.getItem = get
        // use init to initialize the cache: init(set){ getItems, then set(key,
        // item) for each }
        this._init = init
        this._initialized = false
    }
    get items(){
        return Object.values(this._items)
    }
    async init(context){ // context is optional
        if(this._initialized){
            throw new Error('Cannot initialize ItemCache more than once.')
        }
        if(this._init){
            await this._init(this.set.bind(this), context)
        }
        this._initialized = true
    }
    async get(key){
        if(!this._items[key]){
            this.set(key, await this.getItem(key))
        }
        return this._items[key]
    }
    set(key, item){
        this._items[key] = item
    }
}