Class: ActiveRecord::ConnectionAdapters::ConnectionSpecification::Resolver

Inherits:
Object
  • Object
show all
Defined in:
lib/active_record/connection_adapters/connection_specification.rb

Overview

Builds a ConnectionSpecification from user input.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(configurations) ⇒ Resolver

Accepts a hash two layers deep, keys on the first layer represent environments such as “production”. Keys must be strings.


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# File 'lib/active_record/connection_adapters/connection_specification.rb', line 121

def initialize(configurations)
  @configurations = configurations
end

Instance Attribute Details

#configurationsObject (readonly)

Returns the value of attribute configurations


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# File 'lib/active_record/connection_adapters/connection_specification.rb', line 117

def configurations
  @configurations
end

Instance Method Details

#resolve(config) ⇒ Object

Returns a hash with database connection information.

Examples

Full hash Configuration.

configurations = { "production" => { "host" => "localhost", "database" => "foo", "adapter" => "sqlite3" } }
Resolver.new(configurations).resolve(:production)
# => { "host" => "localhost", "database" => "foo", "adapter" => "sqlite3"}

Initialized with URL configuration strings.

configurations = { "production" => "postgresql://localhost/foo" }
Resolver.new(configurations).resolve(:production)
# => { "host" => "localhost", "database" => "foo", "adapter" => "postgresql" }

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# File 'lib/active_record/connection_adapters/connection_specification.rb', line 141

def resolve(config)
  if config
    resolve_connection config
  elsif env = ActiveRecord::ConnectionHandling::RAILS_ENV.call
    resolve_symbol_connection env.to_sym
  else
    raise AdapterNotSpecified
  end
end

#resolve_allObject

Expands each key in @configurations hash into fully resolved hash


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# File 'lib/active_record/connection_adapters/connection_specification.rb', line 152

def resolve_all
  config = configurations.dup

  if env = ActiveRecord::ConnectionHandling::DEFAULT_ENV.call
    env_config = config[env] if config[env].is_a?(Hash) && !(config[env].key?("adapter") || config[env].key?("url"))
  end

  config.reject! { |k, v| v.is_a?(Hash) && !(v.key?("adapter") || v.key?("url")) }
  config.merge! env_config if env_config

  config.each do |key, value|
    config[key] = resolve(value) if value
  end

  config
end

#spec(config) ⇒ Object

Returns an instance of ConnectionSpecification for a given adapter. Accepts a hash one layer deep that contains all connection information.

Example

config = { "production" => { "host" => "localhost", "database" => "foo", "adapter" => "sqlite3" } }
spec = Resolver.new(config).spec(:production)
spec.adapter_method
# => "sqlite3_connection"
spec.config
# => { "host" => "localhost", "database" => "foo", "adapter" => "sqlite3" }

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# File 'lib/active_record/connection_adapters/connection_specification.rb', line 181

def spec(config)
  spec = resolve(config).symbolize_keys

  raise(AdapterNotSpecified, "database configuration does not specify adapter") unless spec.key?(:adapter)

  # Require the adapter itself and give useful feedback about
  #   1. Missing adapter gems and
  #   2. Adapter gems' missing dependencies.
  path_to_adapter = "active_record/connection_adapters/#{spec[:adapter]}_adapter"
  begin
    require path_to_adapter
  rescue LoadError => e
    # We couldn't require the adapter itself. Raise an exception that
    # points out config typos and missing gems.
    if e.path == path_to_adapter
      # We can assume that a non-builtin adapter was specified, so it's
      # either misspelled or missing from Gemfile.
      raise e.class, "Could not load the '#{spec[:adapter]}' Active Record adapter. Ensure that the adapter is spelled correctly in config/database.yml and that you've added the necessary adapter gem to your Gemfile.", e.backtrace

    # Bubbled up from the adapter require. Prefix the exception message
    # with some guidance about how to address it and reraise.
    else
      raise e.class, "Error loading the '#{spec[:adapter]}' Active Record adapter. Missing a gem it depends on? #{e.message}", e.backtrace
    end
  end

  adapter_method = "#{spec[:adapter]}_connection"

  unless ActiveRecord::Base.respond_to?(adapter_method)
    raise AdapterNotFound, "database configuration specifies nonexistent #{spec.config[:adapter]} adapter"
  end

  ConnectionSpecification.new(spec.delete(:name) || "primary", spec, adapter_method)
end