Class: Alchemrest::Response::Pipeline::ExtractPayload

Inherits:
Transform
  • Object
show all
Defined in:
lib/alchemrest/response/pipeline/extract_payload.rb

Overview

A transform that can extract a nested payload from a response body. Takes in an array of symbols, strings, or integers that represent the path to the data you care about. This class assumes the response.body is a hash with string keys, so it calls to_s on all non integer path elements.

Instance Method Summary collapse

Methods inherited from Transform

#failure, #final

Constructor Details

#initialize(_path_to_payload = nil, _allow_empty_response = false) ⇒ ExtractPayload

# All symbols will be converted to strings, and integers will be left alone.

Parameters:

  • path_to_payload (Array<Symbol, String, Integer>) —

    The path to the payload you care about

  • _allow_empty_response (bool) (defaults to: false) —

    Should HTTP 204 OkNoContent empty responses be allowed



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# File 'lib/alchemrest/response/pipeline/extract_payload.rb', line 17

def initialize(_path_to_payload = nil, _allow_empty_response = false) # rubocop:disable Style/OptionalBooleanParameter
  super
end

Instance Method Details

#call(response) ⇒ Object 



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# File 'lib/alchemrest/response/pipeline/extract_payload.rb', line 21

def call(response)
  # If response is empty and the status is 204 (No Content), return nil as the payload
  if response.no_content_response?
    return final(nil) if allow_empty_response?

    return failure(ResponsePipelineError.new("Ok but empty response not allowed"))
  end

  payload = extract_payload(response)
  if payload.nil?
    failure(ResponsePipelineError.new("Response body did not contain expected payload at #{path_to_payload}"))
  else
    success(payload)
  end
end

#extract_payload(response) ⇒ Object 



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# File 'lib/alchemrest/response/pipeline/extract_payload.rb', line 37

def extract_payload(response)
  if path_to_payload.nil?
    response.data
  else
    normalized_path = path_to_payload.map do |path_element|
      if path_element.is_a?(Integer)
        path_element
      else
        path_element.to_s
      end
    end
    response.data.dig(*normalized_path)
  end
  # If our path tries to dig into a non hash, we'll get a TypeError. We want to rescue that and ensure
  # our code continues to safely return a result.
  rescue TypeError
    nil
end