parse-cache

Parse SDK caching for cloud code or browser that actually works.

About

A Parse caching module that works exactly how you would expect it to, with the latest version of Parse SDK. It can be used on cloud code (memory or redis storages) or client Browser code (memory storage only).

Important:

This module was tested using parse-server 2.8.4 and Parse SDK 2.1. There is no warranty using it on versions before these ones.

Install:

You can use npm to install it.

npm install --save parse-cache

You can use it on cloud code, so you need to put it in your package.json and deploy it on your server.

{
  "dependencies": {
    "parse-cache": "*"
  }
}

You can also use it with Parse Javascript SDK on a single page app.

  <script src="https://unpkg.com/[email protected]/dist/parse.min.js"></script>
  <script src="https://unpkg.com/parse-cache/dist/parse-cache.js"></script>

Usage

const Parse = require('parse/node'); // or require('parse') if you are on a Browser
const parseCache = require('parse-cache');

// choose your storage...

// memory storage usage:
parseCache(Parse, 'MyUniqueAppNameOrKey', {engine: 'memory', count: 1000}); // {engine: 'memory', count: 1000} are default values and are optional

// redis storage usage:
parseCache(Parse, 'MyUniqueAppNameOrKey', {
  engine: 'redis',    /* If you don't specify the redis engine,      */
  port: 6379,         /* the query results will be cached in memory (on browser use memory storage). */
  host: 'localhost',
  password: 'optional password'
});

const RecordObject = Parse.Object.extend('Record');
const query = new Parse.Query(RecordObject); // or const query = new Parse.Query('Record');

query
  .cache(30) // The number of seconds to cache the query.  Defaults to 60 seconds.
  .equalTo('someField', 'someValue')
  .find(); // you can use find, first, count, countDocuments, estimatedDocumentCount, aggregate, each, get or distinct

// on a cloud code with 10s ttl
Parse.Cloud.define('test', function(request, response) {
	const query = new Parse.Query('SomeClass');
	query.cache(10).first().then(f => response.success({fromCache: !!f.fromCache})).catch(response.error)
});

// calling your cloud code
curl -X POST -H "X-Parse-Application-Id: your_app_id"  -H "X-Parse-REST-API-Key: your_rest_api_key"  -H "Content-Type: application/json" -d "{}"  https://parseapi.back4app.com/functions/test

// the result should be
{"result":{"fromCache":false}}

// then run the curl again and...
{"result":{"fromCache":true}}

// then run again after 10s and...
{"result":{"fromCache":false}}

You can also pass a custom key into the .cache() method, which you can then use later to clear the cached content.

query
  .cache(30, 'some_custom_cache_key') // The number of seconds to cache the query.  Defaults to 60 seconds.
  .equalTo('someField', 'someValue')
  .find();

To use it on frontend with Parse Javascript SDK just call it using parseCache:

  <script>
    parseCache(Parse, 'MyUniqueAppNameOrKey', {engine: 'memory', count: 1000});
  </script>
  <script>
    var query = new Parse.Query('TestClass');
  
    query.cache(60).find().then(function (results) {
      console.log(1);
      results.map(function (r) {
        console.log(r.fromCache);
      });
      console.log(results);
      query.cache(60).find().then(function (cachedResults) {
        console.log(2);
        cachedResults.map(function (r) {
          console.log(r.fromCache);
        });
        console.log(cachedResults);
      })
    });
  </script>

Insert .cache() into the queries before find, first, count, countDocuments, estimatedDocumentCount, aggregate, each, get or distinct if you want to cache, and they will be cached. Works with select, ascending, descending, and anything else that will modify the results of a query.

Clearing the cache

If you want to clear the cache for a specific query, you must specify the cache key yourself:

query
  .cache(30, 'some_custom_cache_key')
  .find();

parseCache.clearCache('some_custom_cache_key').then(doSomething);

// or using async/await
async function clearCache(key) {
  await parseCache.clearCache(key);
}

If you call parseCache.clearCache(null, cb) or await parseCache.clearCache() without passing a cache key as the first parameter, the entire cache will be cleared for all queries.

Test

npm test