--- title: ASViewController layout: docs permalink: /docs/containers-asviewcontroller.html prevPage: faq.html nextPage: containers-asnodecontroller.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 `UISplitViewController` or as a modal view controller. Benefits of using an `ASViewController`: <ol> <li><b>Save Memory</b>. An <code>ASViewController</code> that goes off screen will automatically reduce the size of the <a href="intelligent-preloading.html">fetch data</a> and <a href="intelligent-preloading.html">display ranges</a> of any of its children. This is key for memory management in large applications. </li> <li><b><a href="asvisibility.html"><code>ASVisibility</code></a> Feature</b>. When used in an <code>ASNavigationController</code> or <code>ASTabBarController</code>, these classes know the exact number of user taps it would take to make the view controller visible.</li> </ol> More features will be added over time, so it is a good idea to base your view controllers off of this class. ## Usage 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/texturegroup/texture/tree/master/examples/ASDKgram">ASDKgram example project</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"> init(models: [Model]) { let tableNode = ASTableNode(style: .plain) super.init(node: tableNode) self.models = models self.tableNode = tableNode self.tableNode.delegate = self self.tableNode.dataSource = self } </pre> </div> </div> <br> <div class = "note"> <b>Conversion Tip</b>: If your app already has a complex view controller hierarchy, it is perfectly fine to have all of them subclass <code>ASViewController</code>. That is to say, even if you don't use <code>ASViewController</code>'s designated initializer <code>-initWithNode:</code>, and only use the <code>ASViewController</code> in the manner of a traditional <code>UIViewController</code>, this will give you the additional node support if you choose to adopt it in different areas your application. </div>