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copied!<blockquote> <p><strong>delegate</strong> <em>noun |ˈdeligit|</em></p> <p>A person sent or authorized to represent others, in particular an elected representative sent to a conference.</p> </blockquote> <p>A delegate in the Cocoa Touch frameworks such as Foundation or UIKit is a separate object instance that is entrusted to listen in to, and optionally decide behaviours on behalf of the delegator.</p> <p>Take the example of <code>UIWebView</code>. The web view can entrust responsibility onto one delegate as long as that instance conforms to the <code>UIWebViewDelegate</code> protocol, that is <em>promises to behave as the web view expects a delegate to behave</em>.</p> <p>The delegate gets called from time to time. Embedded in the delegate method names is information about what the call is about.</p> <ul> <li><code>webView:</code><strong><code>should</code></strong><code>StartLoadWithRequest:navigationType:</code> - Tells the delegate that the webview wants to load a request, and ask the delegate if it <strong>should</strong> do so.</li> <li><code>webView:</code><strong><code>will</code></strong><code>StartLoad:</code> - Tells the delegate that the web view <strong>will</strong> start loading a page, and it is too late to do anything <em>(This is a hypothetical method that is not actually available, I use it as a consistent example)</em>.</li> <li><code>webView:</code><strong><code>did</code></strong><code>FinishLoad:</code> - Tells the delegate that the web view <strong>did</strong> load a page and it is now finished.</li> </ul> <p>The value of using delegation is that you do not need to sub-class <code>UIWebView</code> in order to tweak how it behaves. One objkect can also serve as delegate to many different webviews, or even serve as delegate to many different kinds of classes.</p> <p>A normal <code>UIViewController</code> subclass probably conforms to many delegate protocols, for example <code>UITableViewDelegate</code> to respond to selections in a table, <code>UIActionSheetDelegate</code> to respond to selection from an action sheet, etc.</p>

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