end of subscription rerenders current page

[dpatte]

First, I want to say that I love this package and use it all my projects. Combined with PublishComposite, it has made a significant improvement to the performance of my projects.

But I noticed today that whenever any subs-cache subscription expires, the current template gets rerendered.

In my case, after a template is rendered, I do a scroll to top, and call an unveil function. I noticed after visiting several paths, then waiting for a backlog of subs-cache subscriptions to expire, that my current page was rescrolled to the top as each subs-cache expired.

I am wondering why the current template is rerendered, as presumably it already has all the data it needs from its own template subscriptions.

Is there a way to disable the rerenders triggered by the subs-cache subscription expiries? Or, perhaps can you suggest a way I can detect that the template has already been previously rendered and i can bypass my scroll-to-top function?

Thanks

[jankapunkt]

Hi @dpatte can you provide a very short code example? You can always subscribe within Tracker.nonReactive in order to avoid recomputations, based on subscription handle reactivity. However, I don't know if that's the case in your code.

[dpatte]

Hi. I''ll think of how I might produce a code sample.

But I did try this in my client setup code

subscriptionCache = new SubsCache(Meteor.isProduction? 5:1, -1); // 5 or 1 minutes, no limit of caches
Tracker.nonreactive(subscriptionCache.subscribe);

and still have the issue.

In my original issue, I go to page A (which sets up its own subscription), then go to page B (which also sets up its own subscription), then wait on page B for the first subscription to time-out. When the subscription for page A times out, B rerenders. Note that the two subscriptions are similar but subscribe to different data from a single collection.

I also don't want to lose reactivity from page B's subscription while I'm on page B. But its own data in this scenario doesn't change anyway.

[dpatte]

I understand that in my scenario, the expiry of subscription A changes the content of minimongo triggering the rerender, but it doesn't change what data will be displayed on page B (because what I need for page B, is fully specified in subscription B).

From what I understand, this will always be the case, and a rerender caused from the expiry of an older subscription, in itself, should never cause a change to the contents of the current page. But as subs-cache currently stands, it does.

[dpatte]

i have gotten around the issue by changing what i do in onRendered. When any older subscache expires, subscache still causes a full rerender the complete current page (though in my case it never really needs to), but my logic to scrollToTop is now handled elsewhere, which gets around the issue.