1. A method comprising: collecting multiple parameters relating to a user input into an input method editor (IME), the multiple parameters including: a query submitted by a user through an interface of the IME; and a scenario of a host application that indicates a type of interaction with the host application; selecting, based at least in part on the multiple parameters, an application from one or more applications to provide one or more candidates for the user to select from to input into the host application; sending a request to the application to provide the one or more candidates; receiving, from the application, the one or more candidates for the user to select from to input into the host application, the one or more candidates including a rich candidate comprising at least one of audio, video, an image of weather information, or an image of map information; and displaying the one or more candidates to the user through the interface of the IME for the user to select from to input into the host application.