Class: OMF::SFA::AM::Rest::PromiseHandler

Inherits:
RestHandler
  • Object
show all
Defined in:
lib/omf-sfa/am/am-rest/promise_handler.rb

Constant Summary collapse

@@contexts = 
{}

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from RestHandler

#_format_body, #convert_to_html, #find_handler, #html_template, #initialize, load_api_template, #on_delete, #on_delete_all, #on_get, #on_post, #on_put, parse_resource_uri, render_html, #render_html, service_name, set_service_name

Constructor Details

This class inherits a constructor from OMF::SFA::AM::Rest::RestHandler

Class Method Details

.register_promise(promise, uuid = nil, html_reply = false, collection_set = nil) ⇒ Object 



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# File 'lib/omf-sfa/am/am-rest/promise_handler.rb', line 8

def self.register_promise(promise, uuid = nil, html_reply = false, collection_set = nil)
  debug "Registering promise '#{uuid}' - #{promise}"
  uuid ||= UUIDTools::UUID.random_create
  #uuid = 1 # TODO: REMOVE
  @@contexts[uuid.to_s] = {
    promise: promise,
    html_reply: html_reply,
    collection_set: collection_set || Set.new,
    timestamp: Time.now
  }
  path = "/promises/#{uuid}"
  debug "Redirecting to #{path}"
  return [302, {'Location' => path}, ['Promised, but not ready yet.']]
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/omf-sfa/am/am-rest/promise_handler.rb', line 23

def call(env)
  begin
    req = ::Rack::Request.new(env)
    headers = {
      'Access-Control-Allow-Origin' => '*',
      'Access-Control-Allow-Methods' => 'GET, POST, OPTIONS',
      'Access-Control-Allow-Headers' => 'origin, x-csrftoken, content-type, accept'
    }
    if req.request_method == 'OPTIONS'
      return [200 , headers, ""]
    end

    uuid = req.path_info.split('/')[-1]
    debug "Checking for promise '#{uuid}'"

    unless context = @@contexts[uuid]
      return [404, {}, "Can't find requested promise"]
    end
    context[:timestamp] = Time.now # keep reaper away
    promise = context[:promise]
    case promise.status
    when :pending
      return retry_later(req, context)
    when :rejected
      body = {
        type: 'error',
        error: {
          reason: promise.error_msg,
          code: promise.error_code
        }
      }
      headers['Content-Type'] = 'application/json'
      return [500, headers, JSON.pretty_generate(body)]
    end

    # OK, the promise seems to have been resolved
    content_type, body = promise.value
    #puts ">>>>VALUE #{body.class} - #{content_type}>>>>> #{body}"
    if body.is_a? Thin::AsyncResponse
      return body.finish
    end

    begin
      if content_type == 'text/html'
        #body = self.class.convert_to_html(body, env, Set.new((@coll_handlers || {}).keys))
        body = convert_to_html(body, env, {}, context[:collection_set])
      else
        content_type = 'application/json'
        body = JSON.pretty_generate(body)
      end
    rescue OMF::SFA::Util::PromiseUnresolvedException => pex
      proxy = OMF::SFA::Util::Promise.new
      pex.promise.on_success do |d|
        proxy.resolve [content_type, body]
      end.on_error(proxy)
      uuid = pex.uuid
      path = "/promises/#{uuid}"
      require 'omf-sfa/am/am-rest/promise_handler' # delay loading as PromiseHandler sub classes this class
      self.class.register_promise(proxy, uuid, context[:html_reply], context[:collection_set])
      debug "Redirecting to #{path}"
      return [302, {'Location' => path}, ['Promised, but not ready yet.']]
    end
    headers['Content-Type'] = content_type
    return [200 , headers, (body || '') + "\n"]

  rescue RackException => rex
    return rex.reply
  rescue Exception => ex
    body = {
      type: 'error',
      error: {
        reason: ex.to_s,
        bt: ex.backtrace #.select {|l| !l.start_with?('/') }
      }
    }
    warn "ERROR: #{ex}"
    debug ex.backtrace.join("\n")
    headers['Content-Type'] = 'application/json'
    return [500, headers, JSON.pretty_generate(body)]
  end
end

#retry_later(req, context) ⇒ Object 



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# File 'lib/omf-sfa/am/am-rest/promise_handler.rb', line 105

def retry_later(req, context)
  body = {
    type: 'retry',
    delay: 10, # rex.delay,
    url: absolute_path(req.env['REQUEST_PATH']),
    progress: context[:promise].progress.map do |ts, msg|
      "#{ts.utc.iso8601}: #{msg}"
    end
  }
  debug "Retry later request - #{req.url}"
  headers = {'Content-Type' => 'application/json'}
  return [504, headers, JSON.pretty_generate(body)]
end