register_serializer: Register or fetch a serializer

Description

plumber2 comes with many serializers that should cover almost all standard use cases. Still you might want to provide some of your own, which this function facilitates.

Usage

register_serializer(name, fun, mime_type, default = TRUE)
show_registered_serializers()
get_serializers(serializers = NULL)

Value

For get_serializers a named list of serializer functions named by their mime type. The order given in serializers is preserved.

Arguments

name

The name to register the serializer function to. If already present the current serializer will be overwritten by the one provided by you

fun

A function that, when called, returns a unary function that can serialize a response body to the mime type defined in mime_type

mime_type

The format this serializer creates. You should take care to ensure that the value provided is a standard mime type for the format

default

Should this serializer be part of the default set of serializers

serializers

Serializers to collect. This can either be a character vector of names of registered serializers or a list. If it is a list then the following expectations apply:

Any unnamed elements containing a character vector will be considered as names of registered serializers constructed with default values. The special value "..." will fetch all the serializers that are otherwise not specified in the call.
Any element containing a function are considered as a provided serializer and the element must be named by the mime type the serializer understands
Any remaining named elements will be considered names of registered serializers that should be constructed with the arguments given in the element

Details

If you want to register your own serializer, then the function you register must be a factory function, i.e. a function returning a function. The returned function must accept a single argument which is the response body. All arguments to the factory function should be optional.

Examples

Run this code

# Add a serializer that deparses the value
register_serializer("deparse", function(...) {
  function(x) {
    deparse(x, ...)
  }
}, mime_type = "text/plain")