Class: ActiveRecord::MigrationContext

Inherits:
Object
  • Object
show all
Defined in:
activerecord/lib/active_record/migration.rb

Overview

MigrationContext sets the context in which a migration is run.

A migration context requires the path to the migrations is set in the migrations_paths parameter. Optionally a schema_migration class can be provided. Multiple database applications will instantiate a SchemaMigration object per database. From the Rake tasks, Rails will handle this for you.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(migrations_paths, schema_migration = nil, internal_metadata = nil) ⇒ MigrationContext

Returns a new instance of MigrationContext.



1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
 
# File 'activerecord/lib/active_record/migration.rb', line 1125

def initialize(migrations_paths, schema_migration = nil, internal_metadata = nil)
  if schema_migration == SchemaMigration
    ActiveRecord.deprecator.warn(<<-MSG.squish)
      SchemaMigration no longer inherits from ActiveRecord::Base. If you want
      to use the default connection, remove this argument. If you want to use a
      specific connection, instantiate MigrationContext with the connection's schema
      migration, for example `MigrationContext.new(path, Dog.connection.schema_migration)`.
    MSG

    schema_migration = nil
  end

  if internal_metadata == InternalMetadata
    ActiveRecord.deprecator.warn(<<-MSG.squish)
      SchemaMigration no longer inherits from ActiveRecord::Base. If you want
      to use the default connection, remove this argument. If you want to use a
      specific connection, instantiate MigrationContext with the connection's internal
      metadata, for example `MigrationContext.new(path, nil, Dog.connection.internal_metadata)`.
    MSG

    internal_metadata = nil
  end

  @migrations_paths = migrations_paths
  @schema_migration = schema_migration || SchemaMigration.new(connection)
  @internal_metadata = internal_metadata || InternalMetadata.new(connection)
end

Instance Attribute Details

#internal_metadata ⇒ Object (readonly)

Returns the value of attribute internal_metadata



1123
1124
1125
 
# File 'activerecord/lib/active_record/migration.rb', line 1123

def internal_metadata
  @internal_metadata
end

#migrations_paths ⇒ Object (readonly)

Returns the value of attribute migrations_paths



1123
1124
1125
 
# File 'activerecord/lib/active_record/migration.rb', line 1123

def migrations_paths
  @migrations_paths
end

#schema_migration ⇒ Object (readonly)

Returns the value of attribute schema_migration



1123
1124
1125
 
# File 'activerecord/lib/active_record/migration.rb', line 1123

def schema_migration
  @schema_migration
end

Instance Method Details

#current_environment ⇒ Object

:nodoc:



1267
1268
1269
 
# File 'activerecord/lib/active_record/migration.rb', line 1267

def current_environment # :nodoc:
  ActiveRecord::ConnectionHandling::DEFAULT_ENV.call
end

#current_version ⇒ Object

:nodoc:



1223
1224
1225
1226
 
# File 'activerecord/lib/active_record/migration.rb', line 1223

def current_version # :nodoc:
  get_all_versions.max || 0
rescue ActiveRecord::NoDatabaseError
end

#down(target_version = nil, &block) ⇒ Object

:nodoc:



1197
1198
1199
1200
1201
1202
1203
1204
1205
 
# File 'activerecord/lib/active_record/migration.rb', line 1197

def down(target_version = nil, &block) # :nodoc:
  selected_migrations = if block_given?
    migrations.select(&block)
  else
    migrations
  end

  Migrator.new(:down, selected_migrations, schema_migration, internal_metadata, target_version).migrate
end

#forward(steps = 1) ⇒ Object

:nodoc:



1183
1184
1185
 
# File 'activerecord/lib/active_record/migration.rb', line 1183

def forward(steps = 1) # :nodoc:
  move(:up, steps)
end

#get_all_versions ⇒ Object

:nodoc:



1215
1216
1217
1218
1219
1220
1221
 
# File 'activerecord/lib/active_record/migration.rb', line 1215

def get_all_versions # :nodoc:
  if schema_migration.table_exists?
    schema_migration.integer_versions
  else
    []
  end
end

#last_stored_environment ⇒ Object

:nodoc:

Raises:



1275
1276
1277
1278
1279
1280
1281
1282
1283
 
# File 'activerecord/lib/active_record/migration.rb', line 1275

def last_stored_environment # :nodoc:
  return nil unless connection.internal_metadata.enabled?
  return nil if current_version == 0
  raise NoEnvironmentInSchemaError unless connection.internal_metadata.table_exists?

  environment = connection.internal_metadata[:environment]
  raise NoEnvironmentInSchemaError unless environment
  environment
end

#migrate(target_version = nil, &block) ⇒ Object

Runs the migrations in the migrations_path.

If target_version is nil, migrate will run up.

If the current_version and target_version are both 0 then an empty array will be returned and no migrations will be run.

If the current_version in the schema is greater than the target_version, then down will be run.

If none of the conditions are met, up will be run with the target_version.



1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
 
# File 'activerecord/lib/active_record/migration.rb', line 1166

def migrate(target_version = nil, &block)
  case
  when target_version.nil?
    up(target_version, &block)
  when current_version == 0 && target_version == 0
    []
  when current_version > target_version
    down(target_version, &block)
  else
    up(target_version, &block)
  end
end

#migrations ⇒ Object

:nodoc:



1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
 
# File 'activerecord/lib/active_record/migration.rb', line 1236

def migrations # :nodoc:
  migrations = migration_files.map do |file|
    version, name, scope = parse_migration_filename(file)
    raise IllegalMigrationNameError.new(file) unless version
    version = version.to_i
    name = name.camelize

    MigrationProxy.new(name, version, file, scope)
  end

  migrations.sort_by(&:version)
end

#migrations_status ⇒ Object

:nodoc:



1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
 
# File 'activerecord/lib/active_record/migration.rb', line 1249

def migrations_status # :nodoc:
  db_list = schema_migration.normalized_versions

  file_list = migration_files.filter_map do |file|
    version, name, scope = parse_migration_filename(file)
    raise IllegalMigrationNameError.new(file) unless version
    version = schema_migration.normalize_migration_number(version)
    status = db_list.delete(version) ? "up" : "down"
    [status, version, (name + scope).humanize]
  end

  db_list.map! do |version|
    ["up", version, "********** NO FILE **********"]
  end

  (db_list + file_list).sort_by { |_, version, _| version.to_i }
end

#needs_migration? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


1228
1229
1230
 
# File 'activerecord/lib/active_record/migration.rb', line 1228

def needs_migration? # :nodoc:
  pending_migration_versions.size > 0
end

#open ⇒ Object

:nodoc:



1211
1212
1213
 
# File 'activerecord/lib/active_record/migration.rb', line 1211

def open # :nodoc:
  Migrator.new(:up, migrations, schema_migration, internal_metadata)
end

#pending_migration_versions ⇒ Object

:nodoc:



1232
1233
1234
 
# File 'activerecord/lib/active_record/migration.rb', line 1232

def pending_migration_versions # :nodoc:
  migrations.collect(&:version) - get_all_versions
end

#protected_environment? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


1271
1272
1273
 
# File 'activerecord/lib/active_record/migration.rb', line 1271

def protected_environment? # :nodoc:
  ActiveRecord::Base.protected_environments.include?(last_stored_environment) if last_stored_environment
end

#rollback(steps = 1) ⇒ Object

:nodoc:



1179
1180
1181
 
# File 'activerecord/lib/active_record/migration.rb', line 1179

def rollback(steps = 1) # :nodoc:
  move(:down, steps)
end

#run(direction, target_version) ⇒ Object

:nodoc:



1207
1208
1209
 
# File 'activerecord/lib/active_record/migration.rb', line 1207

def run(direction, target_version) # :nodoc:
  Migrator.new(direction, migrations, schema_migration, internal_metadata, target_version).run
end

#up(target_version = nil, &block) ⇒ Object

:nodoc:



1187
1188
1189
1190
1191
1192
1193
1194
1195
 
# File 'activerecord/lib/active_record/migration.rb', line 1187

def up(target_version = nil, &block) # :nodoc:
  selected_migrations = if block_given?
    migrations.select(&block)
  else
    migrations
  end

  Migrator.new(:up, selected_migrations, schema_migration, internal_metadata, target_version).migrate
end