8c01fccfca
In this case, the user hasn't specified enough about the layout of a node. We default to
0, 0 - but ideally the case should not occur at all. So it's important to help developers
detect these cases and fix them quickly.
An assertion causes developers several problems:
- They can't see important information unless an exception breakpoint is manually added.
- They can't see their layout onscreen and so visually understanding the problem is impossible.
- They can't proceed with testing to trigger other faults in the layout and are blocked fixing one at a time.
A log fixes every one of those problems:
- They can set a breakpoint on the log line very easily if desired.
- They can see their layout display and recognize the 0,0 node even more quickly than the log text information.
- They can see if multiple logs print out, or if the log only occurs for one item in a feed, or certain types --
This helps them debug faster by knowing if the layout is always broken or certain conditions break it.
Since developing with ASLayoutSpecs is an iterative process, it's crucial that we let developers have the
freedom to experiment and test without hitting too many assertions. Fortunately it will be impossible to ignore
these huge logs (full recursive description) and their nodes will be 0, 0 size, so they will get fixed.
Installation
ASDK is available via CocoaPods or Carthage. See our Installation guide for instructions.
Performance Gains
AsyncDisplayKit's basic unit is the node. An ASDisplayNode is an abstraction over UIView, which in turn is an abstraction over CALayer. Unlike views, which can only be used on the main thread, nodes are thread-safe: you can instantiate and configure entire hierarchies of them in parallel on background threads.
To keep its user interface smooth and responsive, your app should render at 60 frames per second — the gold standard on iOS. This means the main thread has one-sixtieth of a second to push each frame. That's 16 milliseconds to execute all layout and drawing code! And because of system overhead, your code usually has less than ten milliseconds to run before it causes a frame drop.
AsyncDisplayKit lets you move image decoding, text sizing and rendering, layout, and other expensive UI operations off the main thread, to keep the main thread available to respond to user interaction.
Advanced Developer Features
As the framework has grown, many features have been added that can save developers tons of time by eliminating common boilerplate style structures common in modern iOS apps. If you've ever dealt with cell reuse bugs, tried to performantly preload data for a page or scroll style interface or even just tried to keep your app from dropping too many frames you can benefit from integrating ASDK.
Learn More
- Read the our Getting Started guide
- Get the sample projects
- Browse the API reference
Getting Help
We use Slack for real-time debugging, community updates, and general talk about ASDK. Signup youself or email AsyncDisplayKit(at)gmail.com to get an invite.
Contributing
We welcome any contributions. See the CONTRIBUTING file for how to get involved.
License
AsyncDisplayKit is BSD-licensed. We also provide an additional patent grant. The files in the /examples directory are licensed under a separate license as specified in each file; documentation is licensed CC-BY-4.0.