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