Internet Plug-Ins

Internet Plug-Ins is a directory in /System/Library/ and /Library/ that contains plug-ins for WebKit. As of iOS 6 and 7, the only default plugin there is QuickTime.

Structure of an Internet Plug-In

Internet plug-ins should have an extension of .webplugin. The principal class should be a subclass of UIView and adopts the WebPlugInViewFactory and WebPlugIn protocols:

@protocol WebPlugInViewFactory <NSObject>
-(UIView*)plugInViewWithArguments:(NSDictionary*)args;
@end

@protocol WebPlugIn
@optional
-(void)webPlugInInitialize;
-(void)webPlugInDestroy;
-(void)webPlugInStop;
-(void)webPlugInStart;

-(id)objectForWebScript;

-(void)webPlugInMainResourceDidFailWithError:(NSError*)error;
-(void)webPlugInMainResourceDidFinishLoading;
-(void)webPlugInMainResourceDidReceiveData:(NSData*)data;
-(void)webPlugInMainResourceDidReceiveResponse:(NSURLResponse*)response;

// UIKit extras
-(BOOL)webPlugInReceivesEventsDirectly;   // inform UIKit that this plug-in should handle the events directly.
-(void)webPlugInLayout;   // similar to UIView's -layoutSubview
-(void)webPlugInDidDraw;  // similar to UIView's -drawRect:
@end

The Info.plist should contain some keys starting with WebPlugin…. See [1] for detail.

References

• Introduction to WebKit Plug-in Programming Topics (on Mac OS X; should be similar on iOS though).