Class: WeatherSage::HTTP::Fetcher

Inherits:
Object
  • Object
show all
Defined in:
lib/weather-sage/http/fetcher.rb

Overview

HTTP fetcher.

Constant Summary collapse

HEADERS =

Request headers.

{
  'Accept'      => 'application/json',
  'User-Agent'  => "weather-sage/#{WeatherSage::VERSION}"
}.freeze

Instance Method Summary collapse

Constructor Details

#initialize(log) ⇒ Fetcher

Create an HTTP Fetcher.



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# File 'lib/weather-sage/http/fetcher.rb', line 18

def initialize(log)
  @log = log
end

Instance Method Details

#fetch(uri, limit = 5) ⇒ Object

Fetch URI, and return response.

Raises an WeatherSage::HTTP::Error on error.



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# File 'lib/weather-sage/http/fetcher.rb', line 27

def fetch(uri, limit = 5)
  # log uri
  @log.info('Fetcher#fetch') { '%p' % [uri] }

  # create request, set headers
  req = Net::HTTP::Get.new(uri)
  HEADERS.each { |k, v| req[k] = v }
  use_ssl = (uri.scheme == 'https')

  # connect, fetch response
  resp = Net::HTTP.start(uri.host, uri.port, use_ssl: use_ssl) do |http|
    http.request(req)
  end

  # log response
  @log.debug('Fetcher#fetch') { 'response: %p' % [resp] }

  # check for error
  case resp
  when Net::HTTPSuccess
    resp
  when Net::HTTPRedirection
    # have we hit the redirect limit?
    unless limit > 0
      # redirect limit hit, raise error
      raise ::WeatherSage::HTTP::Error.new(uri.to_s, resp.code, resp)
    end

    # get new uri
    new_uri = uri.merge(resp['location'])

    # log redirect
    @log.debug('Fetcher#fetch') do
      'redirect: %s' % [JSON.unparse({
        location: resp['location'],
        old_uri: uri,
        new_uri: new_uri,
      })]
    end

    # decriment limit, redirect
    fetch(new_uri, limit - 1)
  else
    # log error
    @log.debug('Fetcher#fetch') do
      'HTTP request failed: url = %s, response = %p' % [uri, resp]
    end

    # raise error
    raise ::WeatherSage::HTTP::Error.new(uri.to_s, resp.code, resp)
  end
end