gearworks-cache

gearworks-cache

A simple in-memory cache used by Gearworks-based Shopify apps, backed by catbox and catbox-memory. Gearworks is the best way to get started with building Shopify applications!

Installing

You can install this package from NPM with the NPM CLI or with Yarn (recommended):

# With NPM
npm install gearworks-cache --save

# With Yarn
yarn add gearworks-cache

Importing

You can import the cache helpers either one function at a time, or all at once, via require or TypeScript's import:

// Import all functions
import * as Cache from "gearworks-cache";

// Import just one function
import { setCacheValue } from "gearworks-cache";

// Import all functions via Node's require:
const Cache = require("gearworks-cache");

// Import just one function via Node's require:
const setCacheValue = require("gearworks-cache").setCacheValue;

Async and Promises

All functions in gearworks-cache return Bluebird promises. If you're using TypeScript or transpiling your JS via Babel, you can use await to wait for the promise to run.

// Wait for the promise with TypeScript/ES6 async/await:
await cache.initialize();

// Or wait for the promise with .then:
cache.initialize().then(() => {
    // Cache has been initialized.
})

Usage

initialize(): Promise

The cache must be initialized at application startup (or at least before you attempt to use any other function).

await Cache.initialize();

setValue(segmentName: string, key: string, value: , ttl: number = 3600000): Promise

Async function that saves the given value to the cache.

segmentName: Name of the segment that the value will reside in, e.g. "auth-invalidation" or "recent-orders". key: Key/name of the value being set. value: Value to set in the cache. Must be json-serializable. ttl: (optional) Length of time that the value will reside in the cache, in milliseconds. Defaults to 60 minutes.

const key = "key_that_can_be_used_to_lookup_value";
const value = {
    foo: "bar"
}
// 24 hours (60 minutes * 60 seconds * 1000 milliseconds * 24 hours).
const time = 60 * 60 * 1000 * 24; 

await Cache.setValue("foo-segment", key, value, time);

getValue(segmentName: string, key: string): Promise<CachedItem>

Async function that gets a value from the cache. Will return undefined if the value is not found.

segmentName: Name of the segment that the value resides in, e.g. "auth-invalidation" or "recent-orders". key: Key/name of the value being retrieved.

const key = "key_that_can_be_used_to_lookup_value";
const cachedItem = await Cache.getValue<{foo: string}>("foo-segment", key);
const value = cachedItem.item;

Returns a CachedItem<T> with the following interface:

interface CachedItem<T> {
    /**
     * The item's value.
     */
    item: T;

    /**
     * The timestamp when the item was stored in the cache (in milliseconds).
     */
    stored: number;

    /**
     * The remaining time-to-live (not the original value used when storing the object).
     */
    ttl: number;
}

deleteValue(segmentName: string, key: string): Promise

Async function that deletes a value from the cache.

segmentName: Name of the segment that the value resides in, e.g. "auth-invalidation" or "recent-orders". key: Key/name of the value being deleted.

const key = "key_that_can_be_used_to_lookup_value";

await Cache.deleteValue("foo-segment", key);