Fetching posts blocks the main thread

[jkmassel]

Steps to reproduce

1. Open the post list for any blog
2. Observe that PostService.syncPostsOfType takes a significant amount of main queue time (1.49s in my simulator, for the blog I was using). ContextManager.saveDerivedContext takes a significant amount of main queue time as well (0.89s in my simulator, for the blog I was using). This work should be done in a background queue to avoid the app being killed by iOS.

I suspect this issue is less pronounced for sites that don't have very large amounts of text content in their blog posts.

[alpavanoglu]

Hey @jkmassel, PostService.syncPostsOfType is indeed directly called from VC's lifecycle which would block the main thread. However the only call I could find to that function is from BlogDetailsViewController.preloadPostsOfType function. And the beginning of that function has the following snippet since 2016

    // Temporarily disable posts preloading until we can properly resolve the issues on:
    BOOL preloadingPostsDisabled = YES;
    if (preloadingPostsDisabled) {
        return;
    }

It was noted to be a temporary disabling but it has been 6 years. So I am guessing there was an another call to that service function when you have faced this issue but it was removed later on. I think we can close this issue simply because the prerequisite won't be satisfied unless somebody fixes that ages old issue.

We can link this issue to the prerequisite maybe? #6151

We can also still dispatch the service call regardless, to make it future proof, if you prefer. Though again it has been 6 years without a change there.