[ASNetworkImageNode] placeholder will fadeout twice

[yxztj]

Hi,

When I'm using ASNetworkImageNode the placeholder is not working as we expected.
In the Placeholder sample which is included in the repo, the logo image is set to imageNode right after node is initialized. The placeholder is working just fine.

  // ASImageNode gets placeholders by default
  _imageNode = [[SlowpokeImageNode alloc] init];
  _imageNode.image = [UIImage imageNamed:@"logo"];

But if I delay setting the image by several seconds(5 seconds for example) as follows:

  // ASImageNode gets placeholders by default
  _imageNode = [[SlowpokeImageNode alloc] init];
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(5.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        _imageNode.image = [UIImage imageNamed:@"logo"];
    });

The placeholderlayer will fadeout at start, then removed from superlayer, and when setting image on 5 seconds later, the placeholderlayer is added to node layer again, fadeout, and removed from superlayer:

After some research on the source code, I found that the placeholderlayer is added to node on each displayWillStart, and fadeout on each displayDidFinished().
As a result in ASNetworkImageNode, the placeholder is fading out twice(once on initial display, and another on image downloaded). Is this the expected behavior or am I missing anything? How can I prevent the first fade out from happening, since the network image hasn't finished downloading yet?

[appleguy]

@yxztj Just wanted to say that I saw this issue when you submitted it, and still intend to fix. Sorry for the delay. The placeholder fade-out feature was added by @rnystrom a while back, and hasn't gotten a lot of usage / testing yet. That's not a good reason for it to have bugs, but suffice it to say that there are a few cool ways we could improve both the API and the implementation.

Right now I'm working on the display system, which is closely related to how placeholders are shown and removed. Because it is still possible for a client to implement their own placeholder mechanics, I will have to prioritize this after the other display work, but it may well be possible to fix at the same time.

Thanks for trying out the framework, and let us know if you have any other issues or questions!

[yxztj]

@appleguy Thanks for the reply. The framework is working just awesome :)
Right now I'll add my own imageView(in ASDisplayNode initWithViewBlock) for custom placeholder logic. Couldn't wait to see the new version of ASDK.

[hannahmbanana]

Went to check this out and the Placeholders example appears to be broken. PR #1728 is working on fixing this.

[maicki]

@hannahmbanana Can you look if #1786 will fix this issue

[hannahmbanana]

@maicki:The placeholder sample does works with PR #1786.

[appleguy]

Closing this issue since it appears resolved.