Class: Ken::Session

Inherits:
Object show all
Defined in:
lib/ken/session.rb

Overview

partially taken from chris eppstein’s freebase api github.com/chriseppstein/freebase/tree

Constant Summary collapse

SERVICES = 
{
  :mqlread => '/api/service/mqlread',
  :mqlwrite => '/api/service/mqlwrite',
  :login => '/api/account/login',
  :upload => '/api/service/upload'
}

Instance Method Summary collapse

Constructor Details

#initialize(host, username, password) ⇒ Session

Initialize a new Ken Session

Ken::Session.new(host{String, IO}, username{String}, password{String})

Parameters:

  • host (String) —

    the API host

  • username (String) —

    freebase username

  • password (String) —

    user password



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# File 'lib/ken/session.rb', line 31

def initialize(host, username, password)
  @host = host
  @username = username
  @password = password
  
  Ken.session = self

  # TODO: check connection
  Ken.logger.info("connection established.")
end

Instance Method Details

#handle_read_error(inner) ⇒ Object

raise an error if the inner response envelope is encoded as an error



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# File 'lib/ken/session.rb', line 62

def handle_read_error(inner)
  unless inner['code'][0, '/api/status/ok'.length] == '/api/status/ok'
    Ken.logger.error "Read Error #{inner.inspect}"
    error = inner['messages'][0]
    raise ReadError.new(error['code'], error['message'])
  end
end

#mqlread(query, options = {}) ⇒ Object

perform a mqlread and return the results TODO: should support multiple queries

you should be able to pass an array of queries



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# File 'lib/ken/session.rb', line 73

def mqlread(query, options = {})
  Ken.logger.info ">>> Sending Query: #{query.to_json}"
  
  envelope = { :qname => {:query => query }}
  
  response = http_request mqlread_service_url, :queries => envelope.to_json
  result = JSON.parse response
  inner = result['qname']
  handle_read_error(inner)
  
  Ken.logger.info "<<< Received Response: #{inner['result'].inspect}"
  
  # will always return the converted ruby hash (from json)
  inner['result']
end

#service_url(svc) ⇒ Object

get the service url for the specified service.



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# File 'lib/ken/session.rb', line 50

def service_url(svc)
  #"http://#{Configuration.instance[:host]}#{SERVICES[svc]}"
  "#{@host}#{SERVICES[svc]}"
end