Add a server layer to a tower

Add a server layer to a tower. This layer will run before the 'shiny' app's server function. This is useful for adding custom logic to the server function without modifying the original server function.

Usage

add_server_layer(tower, layer)

Arguments

tower

A tower

layer

A function that takes input, output, and session and has no return value. This function will be called before the original server function. If you want to short-circuit the server use an exception.

Value

The tower with the layer added