Add a filter to Plumber router

Filters can be used to modify an incoming request, return an error, or return a response prior to the request reaching an endpoint.

Usage

pr_filter(pr, name, expr, serializer)

Arguments

pr

A Plumber API. Note: The supplied Plumber API object will also be updated in place as well as returned by the function.

name

A character string. Name of filter

expr

An expr that resolve to a filter function or a filter function

serializer

A serializer function

Value

The Plumber router with the defined filter added

Examples

if (FALSE) {
pr() %>%
  pr_filter("foo", function(req, res) {
    print("This is filter foo")
    forward()
  }) %>%
  pr_get("/hi", function() "Hello") %>%
  pr_run()
}