abstract struct Athena::Routing::Response::Writer
- Athena::Routing::Response::Writer
- Struct
- Value
- Object
Overview
Determines how the content of an ART::Response
will be written to the requests' response IO
.
By default the content is written directly to the requests' response IO
via ART::Response::DirectWriter
.
However, custom writers can be implemented to customize that behavior. The most common use case would be for compression.
Writers can also be defined as services and injected into a listener if they require additional external dependencies.
Example
require "athena"
require "compress/gzip"
# Define a custom writer to gzip the response
struct GzipWriter < ART::Response::Writer
def write(output : IO, & : IO -> Nil) : Nil
Compress::Gzip::Writer.open(output) do |gzip_io|
yield gzip_io
end
end
end
# Define a new event listener to handle applying this writer
@[ADI::Register]
struct CompressionListener
include AED::EventListenerInterface
def self.subscribed_events : AED::SubscribedEvents
AED::SubscribedEvents{
ART::Events::Response => -256, # Listen on the Response event with a very low priority
}
end
def call(event : ART::Events::Response, dispatcher : AED::EventDispatcherInterface) : Nil
# If the request supports gzip encoding
if event.request.headers.includes_word?("accept-encoding", "gzip")
# Change the `ART::Response` object's writer to be our `GzipWriter`
event.response.writer = GzipWriter.new
# Set the encoding of the response to gzip
event.response.headers["content-encoding"] = "gzip"
end
end
end
class ExampleController < ART::Controller
@[ART::Get("/users")]
def users : Array(User)
User.all
end
end
ART.run
# GET /users # => [{"id":1,...},...] (gzipped)
Direct Known Subclasses
Defined in:
response.crConstructors
Instance Method Summary
- #initialize
-
#write(output : IO, & : IO -> Nil) : Nil
Accepts an output
IO
that the content of the response should be written to.
Constructor Detail
Instance Method Detail
abstract
def write(output : IO, & : IO -> Nil) : Nil
#
Accepts an output IO
that the content of the response should be written to.