Module: Tem::Transport::AutoConfigurator

Defined in:
lib/tem/transport/auto_configurator.rb

Overview

Automatic configuration code.

Constant Summary collapse

ENVIRONMENT_VARIABLE_NAME =

The name of the environment variable that might supply the transport configuration.

'TEM_PORT'
DEFAULT_CONFIGURATIONS =

The default configurations to be tried if no configuration is specified.

[
  { :class => JcopRemoteTransport,
    :opts => { :host => '127.0.0.1', :port => 8050} },
  { :class => PcscTransport, :opts => { :reader_index => 0 }}
]

Class Method Summary collapse

Class Method Details

.auto_transport ⇒ Object

Creates a transport based on available configuration information.



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# File 'lib/tem/transport/auto_configurator.rb', line 18

def self.auto_transport
  configuration = env_configuration
  return try_transport(configuration) if configuration
  
  DEFAULT_CONFIGURATIONS.each do |config|
    transport = try_transport(config)
    return transport if transport
  end
  return nil
end

.env_configuration ⇒ Object

Retrieves transport configuration information from an environment variable.

:call-seq:

AutoConfigurator.env_configuration -> hash

The returned configuration has the keys required by AutoConfigurator#try_transport



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# File 'lib/tem/transport/auto_configurator.rb', line 36

def self.env_configuration
  return nil unless conf = ENV[ENVIRONMENT_VARIABLE_NAME]
  
  case conf[0]
  when ?:
    # :8050 -- JCOP emulator at port 8050
    transport_class = JcopRemoteTransport
    transport_opts = { :host => '127.0.0.1' }
    transport_opts[:port] = conf[1..-1].to_i
  when ?@
    # @127.0.0.1:8050 -- JCOP emulator at host 127.0.0.1 port 8050
    transport_class = JcopRemoteTransport
    port_index = conf.rindex(?:) || conf.length
    transport_opts = { :host => conf[1...port_index] }
    transport_opts[:port] = conf[(port_index + 1)..-1].to_i
  when ?#
    # #2 -- 2nd PC/SC reader in the system
    transport_class = PcscTransport
    transport_opts = { :reader_index => conf[1..-1].to_i - 1 }
  else
    # Reader Name -- the PC/SC reader with the given name
    transport_class = PcscTransport
    transport_opts = { :reader_name => conf }
  end
  
  transport_opts[:port] = 8050 if transport_opts[:port] == 0
  if transport_opts[:reader_index] and transport_opts[:reader_index] < 0
    transport_opts[:reader_index] = 0
  end
  { :class => transport_class, :opts => transport_opts }
end

.try_transport(configuration) ⇒ Object

Attempts to create a new TEM transport with the given configuration. :call-seq:

AutoConfigurator.try_transport(configuration) -> Transport or nil

The configuration should have the following keys:

class:: the Ruby class implementing the transport
opts:: the options to be passed to the implementation's constructor



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# File 'lib/tem/transport/auto_configurator.rb', line 75

def self.try_transport(configuration)
  raise 'No transport class specified' unless configuration[:class]
  begin
    transport = configuration[:class].new(configuration[:opts] || {})
    transport.connect
    return transport
  rescue Exception
    return nil
  end
end