---
title: ASViewController
layout: docs
permalink: /docs/containers-asviewcontroller.html
next: containers-astablenode.html
---

`ASViewController` is a subclass of `UIViewController` that adds several useful features for hosting `ASDisplayNode` hierarchies. 

An `ASViewController` can be used in place of any `UIViewController` - including within a `UINavigationController`, `UITabBarController` and `UISpitViewController` or as a modal view controller.

One of the main benefits to using an `ASViewController` is to save memory. An `ASViewController` that goes off screen will automatically reduce the size of the fetch data and display ranges of any of its children. This is key for memory management in large applications. 

More features will be added over time, so it is a good idea to base your view controllers off of this class. 

A `UIViewController` provides a view of its own. An `ASViewController` is assigned a node to manage in its designated initializer `initWithNode:`. 

Consider the following `ASViewController` subclass `PhotoFeedNodeController` from the <a href="https://github.com/facebook/AsyncDisplayKit/tree/master/examples/ASDKgram">ASDKgram sample app</a> that would like to use a table node as its managed node. 

This table node is assigned to the `ASViewController` in its `initWithNode:` designated initializer method.

<div class = "highlight-group">
<span class="language-toggle"><a data-lang="swift" class="swiftButton">Swift</a><a data-lang="objective-c" class = "active objcButton">Objective-C</a></span>
<div class = "code">
  <pre lang="objc" class="objcCode">
- (instancetype)init
{
  _tableNode = [[ASTableNode alloc] initWithStyle:UITableViewStylePlain];
  self = [super initWithNode:_tableNode];
  
  if (self) {
    _tableNode.dataSource = self;
    _tableNode.delegate = self;
  }
  
  return self;
}
  </pre>

  <pre lang="swift" class = "swiftCode hidden">
func initWithModel(models: Array<Model>) {
	let tableNode = ASTableNode(style:.Plain)

    super.initWithNode(tableNode)

    self.models = models
    
    self.tableNode = tableNode
    self.tableNode.dataSource = self
    
    return self
}
</pre>
</div>
</div>

<div class = "note">
If your app already has a complex view controller hierarchy, it is perfectly fine to have all of them subclass `ASViewController`. That is to say, even if you don't use `ASViewController`'s designated initializer `initiWithNode:`, and only use the `ASViewController` in the manner of a traditional `UIVieWController`, this will give you the additional node support if you choose to adopt it in different areas your application. 
</div>