vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb

   1 module ActiveRecord
   2   class Base
   3     class ConnectionSpecification #:nodoc:
   4       attr_reader :config, :adapter_method
   5       def initialize (config, adapter_method)
   6         @config, @adapter_method = config, adapter_method
   7       end
   8     end
   9
  10     ##
  11     # :singleton-method:
  12     # The connection handler
  13     cattr_accessor :connection_handler, :instance_writer => false
  14     @@connection_handler = ConnectionAdapters::ConnectionHandler.new
  15
  16     # Returns the connection currently associated with the class. This can
  17     # also be used to "borrow" the connection to do database work that isn't
  18     # easily done without going straight to SQL.
  19     def connection
  20       self.class.connection
  21     end
  22
  23     # Establishes the connection to the database. Accepts a hash as input where
  24     # the <tt>:adapter</tt> key must be specified with the name of a database adapter (in lower-case)
  25     # example for regular databases (MySQL, Postgresql, etc):
  26     #
  27     #   ActiveRecord::Base.establish_connection(
  28     #     :adapter  => "mysql",
  29     #     :host     => "localhost",
  30     #     :username => "myuser",
  31     #     :password => "mypass",
  32     #     :database => "somedatabase"
  33     #   )
  34     #
  35     # Example for SQLite database:
  36     #
  37     #   ActiveRecord::Base.establish_connection(
  38     #     :adapter => "sqlite",
  39     #     :database  => "path/to/dbfile"
  40     #   )
  41     #
  42     # Also accepts keys as strings (for parsing from YAML for example):
  43     #
  44     #   ActiveRecord::Base.establish_connection(
  45     #     "adapter" => "sqlite",
  46     #     "database"  => "path/to/dbfile"
  47     #   )
  48     #
  49     # The exceptions AdapterNotSpecified, AdapterNotFound and ArgumentError
  50     # may be returned on an error.
  51     def self.establish_connection(spec = nil)
  52       case spec
  53         when nil
  54           raise AdapterNotSpecified unless defined? RAILS_ENV
  55           establish_connection(RAILS_ENV)
  56         when ConnectionSpecification
  57           @@connection_handler.establish_connection(name, spec)
  58         when Symbol, String
  59           if configuration = configurations[spec.to_s]
  60             establish_connection(configuration)
  61           else
  62             raise AdapterNotSpecified, "#{spec} database is not configured"
  63           end
  64         else
  65           spec = spec.symbolize_keys
  66           unless spec.key?(:adapter) then raise AdapterNotSpecified, "database configuration does not specify adapter" end
  67
  68           begin
  69             require 'rubygems'
  70             gem "activerecord-#{spec[:adapter]}-adapter"
  71             require "active_record/connection_adapters/#{spec[:adapter]}_adapter"
  72           rescue LoadError
  73             begin
  74               require "active_record/connection_adapters/#{spec[:adapter]}_adapter"
  75             rescue LoadError
  76               raise "Please install the #{spec[:adapter]} adapter: `gem install activerecord-#{spec[:adapter]}-adapter` (#{$!})"
  77             end
  78           end
  79
  80           adapter_method = "#{spec[:adapter]}_connection"
  81           if !respond_to?(adapter_method)
  82             raise AdapterNotFound, "database configuration specifies nonexistent #{spec[:adapter]} adapter"
  83           end
  84
  85           remove_connection
  86           establish_connection(ConnectionSpecification.new(spec, adapter_method))
  87       end
  88     end
  89
  90     class << self
  91       # Deprecated and no longer has any effect.
  92       def allow_concurrency
  93         ActiveSupport::Deprecation.warn("ActiveRecord::Base.allow_concurrency has been deprecated and no longer has any effect. Please remove all references to allow_concurrency.")
  94       end
  95
  96       # Deprecated and no longer has any effect.
  97       def allow_concurrency=(flag)
  98         ActiveSupport::Deprecation.warn("ActiveRecord::Base.allow_concurrency= has been deprecated and no longer has any effect. Please remove all references to allow_concurrency=.")
  99       end
 100
 101       # Deprecated and no longer has any effect.
 102       def verification_timeout
 103         ActiveSupport::Deprecation.warn("ActiveRecord::Base.verification_timeout has been deprecated and no longer has any effect. Please remove all references to verification_timeout.")
 104       end
 105
 106       # Deprecated and no longer has any effect.
 107       def verification_timeout=(flag)
 108         ActiveSupport::Deprecation.warn("ActiveRecord::Base.verification_timeout= has been deprecated and no longer has any effect. Please remove all references to verification_timeout=.")
 109       end
 110
 111       # Returns the connection currently associated with the class. This can
 112       # also be used to "borrow" the connection to do database work unrelated
 113       # to any of the specific Active Records.
 114       def connection
 115         retrieve_connection
 116       end
 117
 118       def connection_pool
 119         connection_handler.retrieve_connection_pool(self)
 120       end
 121
 122       def retrieve_connection
 123         connection_handler.retrieve_connection(self)
 124       end
 125
 126       # Returns true if +ActiveRecord+ is connected.
 127       def connected?
 128         connection_handler.connected?(self)
 129       end
 130
 131       def remove_connection(klass = self)
 132         connection_handler.remove_connection(klass)
 133       end
 134
 135       delegate :clear_active_connections!, :clear_reloadable_connections!,
 136         :clear_all_connections!,:verify_active_connections!, :to => :connection_handler
 137     end
 138   end
 139 end