Issue #21773 has been reported by rosa (Rosa Gutierrez ). ---------------------------------------- Feature #21773: Support for setting encoding when a block is passed to `Net::HTTPResponse.read_body` https://bugs.ruby-lang.org/issues/21773 * Author: rosa (Rosa Gutierrez ) * Status: Open ---------------------------------------- Hi everyone, This feature request could be considered a follow-up to https://bugs.ruby-lang.org/issues/2567. Opting in to automatic detection of the right encoding for the body when passing a block to `read_body` results in an error as follows: ``` ruby require "net/http" uri = URI.parse("https://rosa.codes") http = Net::HTTP.new(uri.host, uri.port).tap { it.use_ssl = true } req = Net::HTTP::Get.new(uri) http.request(req) do |response| response.body_encoding = true body = +"" response.read_body do |str| body << str end end # => lib/net/http/response.rb:380:in 'Net::HTTPResponse#read_body': undefined method 'force_encoding' for an instance of Net::ReadAdapter (NoMethodError) ``` It's expected this doesn't work because when passing a block, the body is not kept anywhere in the `Net::HTTPResponse` object, each segment read is just passed to the block via the wrapping `Net::ReadAdapter`. In the case I was handling, I required both to read the body using a block and also set the encoding in the final body. I didn't want to duplicate all the code to do the encoding detection, as it's not trivial. I preferred to rely on the `Net::HTTP` implementation of it. I ended up doing something different, along these lines: ```ruby require "net/http" require "active_support" class Body attr_reader :content delegate_missing_to :content def initialize(&block) @block = block @content = +"" end def <<(str) @content << str @block.call(str) if @block end end uri = URI.parse("https://rosa.codes") http = Net::HTTP.new(uri.host, uri.port).tap { it.use_ssl = true } req = Net::HTTP::Get.new(uri) http.request(req) do |response| response.body_encoding = true dest = Body.new response.read_body(dest) end ``` But this got me wondering whether: - The error that happens when calling `force_encoding` on an instance of `Net::ReadAdapter` should be handled more gracefully or in a more informative way for the user. - This could be better supported by `Net::HTTP`. All the pieces are there; there just isn't an easy way to put them together. There's a way to detect the encoding, there's a way to set a body directly in the response, via `Net::HTTPResponse#body=`, but there's no way to trigger the encoding detection and set it in the body besides the first time the body is read. Thanks for the consideration! -- https://bugs.ruby-lang.org/