b runHandler(b() defn, String prefix="")
defn: The default function to run if none was specified.
prefix: An optional prefix to allow multiple
runHandlercalls to coexist.
This runs the function called by the previous page of the application, or runs the provided default function if none was called. All functions called in this way must have the same return type. The default function takes no parameters, and all other functions take a single parameter representing the application state.
The optional prefix allows handlers to have different namespaces, which allows multiple handler functions to safely coexist at various parts of the web application. Note that it is not possible for a single form submission or link to call more than one handler (though they will call the default function).