Meteor Subscription Cache

This package is similar to meteorhacks:subs-manager. The goal is to cache subscriptions.

Suppose you are subscribing to a post:

sub = Meteor.subscribe('post', postId)

When the user clicks to another page, you typically want to stop the subscription

subs.stop()

This will clean up and throw away the data you don't need. But what if the user clicks back immediately after you stopped the subscription? Now you have resubscribe to the same data. This is a waste. SubsCache allows you to cache your subscriptions. When you stop a SubCache subscription, it will start a setTimeout and stop the subscription after expireAfter minutes. If you resubscribe to the same subscription before the cached subscription expired, then the setTimeout is cleared and the subscription is restored.

meteorhacks:subs-manager comparison

1. SubsManager will stop your subscription "expireIn" minutes after your subscribe. SubsCache will stop your subscription "expireAfter" minutes after you stop (or the current reative computation stops).

2. SubsManager does not have a ready function for each subscription. subsManager.ready tells you if all cached subscriptions are ready. SubsCache as subsCache.allReady() and individual sub.ready()

3. SubsManager does not allow you to have subscriptions with different expiration times in the same cache. SubsCache allows you set the default expireAfter upon initialization but you can use subscribeFor(expireAfter, ...) to subscribe and cache for a different time.

4. SubsManager does not allow infinite items in a cache. SubsCache does if you set cacheLimit to -1.

5. SubsManager does not allow subscriptions that never expire. SubsCache does if you set expireAfter to -1.

Getting Started

meteor add ccorcos:subs-cache

Initialize with optional expireAfter (default 5) and cacheLimit (default 10). expireAfter is the number of minutes after a subscription is stopped without having been restarted before truely stopping it. If set to -1, the subscription will never expire. cacheLimit is the max number of subscriptions to cache. Set to -1 for unlimited capacity.

subsCache = new SubsCache({
  expireAter: 5,  // minutes
  cacheLimit: 10
});

• subsCache.allReady() tells you if all subscriptions in the cache are ready

• sub = subsCache.subscribe(...) creates a subscription just like Meteor.subscribe

• sub = subsCache.subscribeFor(expireIn, ...) allow you to set the expiration other than the defualt.

• subsCache.clear() will stop all subscription immediately

• subsCache.onReady(func) will call a function once all subscription are ready

• sub.stop() will cache a subscription and stop after expireAfter unless restarted with sub.restart()

• sub.stopNow() will stop a subscription immediately and remove it from the cache.

• sub.ready() tells you if an individual subscription is ready

• sub.onReady(func) will call a function once an individual subscription is ready