1. A method comprising: by a server computing device, receiving from a client computing device a request for a view of a user interface of a native application executing on the client computing device, wherein the view includes one or more first user-interface components, and wherein the native application is an application installed locally on the client computing device; by a server computing device, determining a user agent type of the client computing device; by a server computing device, selecting one or more second user-interface components based on the user agent type of the client computing device, the one or more second user-interface components being associated with a native feature of the client computing device, the native feature comprising a hardware component native to the second-computing device; by a server computing device, generating code implementing a structured document that represents the view, the structured document comprising the one or more first user-interface components and the one or more second user-interface components; and by a server computing device, sending the code to the client computing device.