Class: Generators::DeclareSchema::Migration::Migrator

Inherits:
Object
  • Object
show all
Defined in:
lib/generators/declare_schema/migration/migrator.rb

Defined Under Namespace

Classes: Error

Constant Summary collapse

SchemaDumper = 
case Rails::VERSION::MAJOR
when 4
  ActiveRecord::SchemaDumper
else
  ActiveRecord::ConnectionAdapters::SchemaDumper
end

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(ambiguity_resolver = {}) ⇒ Migrator

Returns a new instance of Migrator.



51
52
53
54
55
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 51

def initialize(ambiguity_resolver = {})
  @ambiguity_resolver = ambiguity_resolver
  @drops = []
  @renames = nil
end

Class Attribute Details

.active_record_class ⇒ Object (readonly)

Returns the value of attribute active_record_class.



19
20
21
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 19

def active_record_class
  @active_record_class
end

.before_generating_migration_callback ⇒ Object (readonly)

Returns the value of attribute before_generating_migration_callback.



19
20
21
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 19

def before_generating_migration_callback
  @before_generating_migration_callback
end

.ignore_models ⇒ Object

Returns the value of attribute ignore_models.



18
19
20
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 18

def ignore_models
  @ignore_models
end

.ignore_tables ⇒ Object

Returns the value of attribute ignore_tables.



18
19
20
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 18

def ignore_tables
  @ignore_tables
end

Instance Attribute Details

#renames ⇒ Object

Returns the value of attribute renames.



57
58
59
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 57

def renames
  @renames
end

Class Method Details

.always_ignore_tables ⇒ Object 



160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 160

def self.always_ignore_tables
  sessions_table =
    begin
      if defined?(CGI::Session::ActiveRecordStore::Session) &&
         defined?(ActionController::Base) &&
         ActionController::Base.session_store == CGI::Session::ActiveRecordStore
        CGI::Session::ActiveRecordStore::Session.table_name
      end
    rescue
      nil
    end

  [
    'schema_info',
    ActiveRecord::Base.try(:schema_migrations_table_name) || 'schema_migrations',
    ActiveRecord::Base.try(:internal_metadata_table_name) || 'ar_internal_metadata',
    sessions_table
  ].compact
end

.before_generating_migration(&block) ⇒ Object 



42
43
44
45
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 42

def before_generating_migration(&block)
  block or raise ArgumentError, 'A block is required when setting the before_generating_migration callback'
  @before_generating_migration_callback = block
end

.connection ⇒ Object 



38
39
40
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 38

def connection
  ActiveRecord::Base.connection
end

.default_migration_name ⇒ Object 



32
33
34
35
36
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 32

def default_migration_name
  existing = Dir["#{Rails.root}/db/migrate/*declare_schema_migration*"]
  max = existing.grep(/([0-9]+)\.rb$/) { Regexp.last_match(1).to_i }.max.to_i
  "declare_schema_migration_#{max + 1}"
end

.run(renames = {}) ⇒ Object 



26
27
28
29
30
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 26

def run(renames = {})
  g = Migrator.new
  g.renames = renames
  g.generate
end

Instance Method Details

#add_column_back(model, current_table_name, col_name) ⇒ Object 



525
526
527
528
529
530
531
532
533
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 525

def add_column_back(model, current_table_name, col_name)
  with_previous_model_table_name(model, current_table_name) do
    column = model.columns_hash[col_name] or raise "no columns_hash entry found for #{col_name} in #{model.inspect}"
    col_spec = ::DeclareSchema::Model::Column.new(model, current_table_name, column)
    schema_attributes = col_spec.schema_attributes
    type = schema_attributes.delete(:type) or raise "no :type found in #{schema_attributes.inspect}"
    ["add_column :#{current_table_name}, :#{col_name}, #{type.inspect}", *format_options(schema_attributes)].join(', ')
  end
end

#add_table_back(table) ⇒ Object 



561
562
563
564
565
566
567
568
569
570
571
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 561

def add_table_back(table)
  dumped_schema_stream = StringIO.new
  SchemaDumper.send(:new, ActiveRecord::Base.connection).send(:table, table, dumped_schema_stream)

  dumped_schema = dumped_schema_stream.string.strip.gsub!("\n  ", "\n")
  if connection.class.name.match?(/mysql/i)
    fix_mysql_charset_and_collation(dumped_schema)
  else
    dumped_schema
  end
end

#change_column_back(model, current_table_name, col_name) ⇒ Object 



535
536
537
538
539
540
541
542
543
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 535

def change_column_back(model, current_table_name, col_name)
  with_previous_model_table_name(model, current_table_name) do
    column = model.columns_hash[col_name] or raise "no columns_hash entry found for #{col_name} in #{model.inspect}"
    col_spec = ::DeclareSchema::Model::Column.new(model, current_table_name, column)
    schema_attributes = col_spec.schema_attributes
    type = schema_attributes.delete(:type) or raise "no :type found in #{schema_attributes.inspect}"
    ["change_column #{current_table_name.to_sym.inspect}", col_name.to_sym.inspect, type.to_sym.inspect, *format_options(schema_attributes)].join(', ')
  end
end

#change_foreign_key_constraints(model, old_table_name) ⇒ Object 



445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 445

def change_foreign_key_constraints(model, old_table_name)
  ActiveRecord::Base.connection.class.name.match?(/SQLite3Adapter/) and raise ArgumentError, 'SQLite does not support foreign keys'
  ::DeclareSchema.default_generate_foreign_keys or return [[], []]

  new_table_name = model.table_name
  existing_fks = ::DeclareSchema::Model::ForeignKeyDefinition.for_model(model, old_table_name)
  model_fks = model.constraint_specs

  undo_add_fks = []
  add_fks = (model_fks - existing_fks).map do |fk|
    # next if fk.parent.constantize.abstract_class || fk.parent == fk.model.class_name
    undo_add_fks << remove_foreign_key(old_table_name, fk.constraint_name)
    fk.to_add_statement
  end

  undo_drop_fks = []
  drop_fks = (existing_fks - model_fks).map do |fk|
    undo_drop_fks << fk.to_add_statement
    remove_foreign_key(new_table_name, fk.constraint_name)
  end

  [drop_fks + add_fks, undo_add_fks + undo_drop_fks]
end

#change_indexes(model, old_table_name, to_remove) ⇒ Object 



405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 405

def change_indexes(model, old_table_name, to_remove)
  ::DeclareSchema.default_generate_indexing or return [[], []]

  new_table_name = model.table_name
  existing_indexes = ::DeclareSchema::Model::IndexDefinition.for_model(model, old_table_name)
  model_indexes_with_equivalents = model.index_definitions_with_primary_key
  model_indexes = model_indexes_with_equivalents.map do |i|
    if i.explicit_name.nil?
      if (existing = existing_indexes.find { |e| i != e && e.equivalent?(i) })
        i.with_name(existing.name)
      end
    end || i
  end
  existing_has_primary_key = existing_indexes.any? do |i|
    i.name == ::DeclareSchema::Model::IndexDefinition::PRIMARY_KEY_NAME &&
      !i.fields.all? { |f| to_remove.include?(f) } # if we're removing the primary key column(s), the primary key index will be removed too
  end
  model_has_primary_key    = model_indexes.any?    { |i| i.name == ::DeclareSchema::Model::IndexDefinition::PRIMARY_KEY_NAME }

  undo_add_indexes = []
  add_indexes = (model_indexes - existing_indexes).map do |i|
    undo_add_indexes << drop_index(old_table_name, i.name) unless i.name == ::DeclareSchema::Model::IndexDefinition::PRIMARY_KEY_NAME
    i.to_add_statement(new_table_name, existing_has_primary_key)
  end
  undo_drop_indexes = []
  drop_indexes = (existing_indexes - model_indexes).map do |i|
    undo_drop_indexes << i.to_add_statement(old_table_name, model_has_primary_key)
    drop_index(new_table_name, i.name) unless i.name == ::DeclareSchema::Model::IndexDefinition::PRIMARY_KEY_NAME
  end.compact

  # the order is important here - adding a :unique, for instance needs to remove then add
  [drop_indexes + add_indexes, undo_add_indexes + undo_drop_indexes]
end

#change_table(model, current_table_name) ⇒ Object 



311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 311

def change_table(model, current_table_name)
  new_table_name = model.table_name

  db_columns = model.connection.columns(current_table_name).index_by(&:name)
  key_missing = db_columns[model._defined_primary_key].nil? && model._defined_primary_key.present?
  if model._defined_primary_key.present?
    db_columns.delete(model._defined_primary_key)
  end

  model_column_names = model.field_specs.keys.map(&:to_s)
  db_column_names = db_columns.keys.map(&:to_s)

  to_add = model_column_names - db_column_names
  to_add += [model._defined_primary_key] if key_missing && model._defined_primary_key.present?
  to_remove = db_column_names - model_column_names
  to_remove -= [model._defined_primary_key.to_sym] if model._defined_primary_key.present?

  to_rename = extract_column_renames!(to_add, to_remove, new_table_name)

  db_column_names -= to_rename.keys
  db_column_names |= to_rename.values
  to_change = db_column_names & model_column_names

  renames = to_rename.map do |old_name, new_name|
    "rename_column :#{new_table_name}, :#{old_name}, :#{new_name}"
  end
  undo_renames = to_rename.map do |old_name, new_name|
    "rename_column :#{new_table_name}, :#{new_name}, :#{old_name}"
  end

  to_add = to_add.sort_by { |c| model.field_specs[c]&.position || 0 }
  adds = to_add.map do |c|
    args =
      if (spec = model.field_specs[c])
        options = spec.sql_options.merge(fk_field_options(model, c))
        [":#{spec.type}", *format_options(options.compact)]
      else
        [":integer"]
      end
    ["add_column :#{new_table_name}, :#{c}", *args].join(', ')
  end
  undo_adds = to_add.map do |c|
    "remove_column :#{new_table_name}, :#{c}"
  end

  removes = to_remove.map do |c|
    "remove_column :#{new_table_name}, :#{c}"
  end
  undo_removes = to_remove.map do |c|
    add_column_back(model, current_table_name, c)
  end

  old_names = to_rename.invert
  changes = []
  undo_changes = []
  to_change.each do |col_name_to_change|
    orig_col_name      = old_names[col_name_to_change] || col_name_to_change
    column             = db_columns[orig_col_name] or raise "failed to find column info for #{orig_col_name.inspect}"
    spec               = model.field_specs[col_name_to_change] or raise "failed to find field spec for #{col_name_to_change.inspect}"
    spec_attrs         = spec.schema_attributes(column)
    column_declaration = ::DeclareSchema::Model::Column.new(model, current_table_name, column)
    col_attrs          = column_declaration.schema_attributes
    normalized_schema_attrs = spec_attrs.merge(fk_field_options(model, col_name_to_change))

    if !::DeclareSchema::Model::Column.equivalent_schema_attributes?(normalized_schema_attrs, col_attrs)
      type = normalized_schema_attrs.delete(:type) or raise "no :type found in #{normalized_schema_attrs.inspect}"
      changes << ["change_column #{new_table_name.to_sym.inspect}", col_name_to_change.to_sym.inspect,
                  type.to_sym.inspect, *format_options(normalized_schema_attrs)].join(", ")
      undo_changes << change_column_back(model, current_table_name, orig_col_name)
    end
  end

  index_changes, undo_index_changes = change_indexes(model, current_table_name, to_remove)
  fk_changes, undo_fk_changes = if ActiveRecord::Base.connection.class.name.match?(/SQLite3Adapter/)
                                  [[], []]
                                else
                                  change_foreign_key_constraints(model, current_table_name)
                                end
  table_options_changes, undo_table_options_changes = if ActiveRecord::Base.connection.class.name.match?(/mysql/i)
                                                        change_table_options(model, current_table_name)
                                                      else
                                                        [[], []]
                                                      end

  [(renames + adds + removes + changes)                     * "\n",
   (undo_renames + undo_adds + undo_removes + undo_changes) * "\n",
   index_changes                                            * "\n",
   undo_index_changes                                       * "\n",
   fk_changes                                               * "\n",
   undo_fk_changes                                          * "\n",
   table_options_changes                                    * "\n",
   undo_table_options_changes                               * "\n"]
end

#change_table_options(model, current_table_name) ⇒ Object 



504
505
506
507
508
509
510
511
512
513
514
515
516
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 504

def change_table_options(model, current_table_name)
  old_options_definition = ::DeclareSchema::Model::TableOptionsDefinition.for_model(model, current_table_name)
  new_options_definition = ::DeclareSchema::Model::TableOptionsDefinition.new(model.table_name, table_options_for_model(model))

  if old_options_definition.equivalent?(new_options_definition)
    [[], []]
  else
    [
      [new_options_definition.alter_table_statement],
      [old_options_definition.alter_table_statement]
    ]
  end
end

#connection ⇒ Object 



76
77
78
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 76

def connection
  self.class.connection
end

#create_constraints(model) ⇒ Object 



301
302
303
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 301

def create_constraints(model)
  model.constraint_specs.map { |fk| fk.to_add_statement }
end

#create_field(field_spec, field_name_width) ⇒ Object 



305
306
307
308
309
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 305

def create_field(field_spec, field_name_width)
  options = field_spec.sql_options.merge(fk_field_options(field_spec.model, field_spec.name))
  args = [field_spec.name.inspect] + format_options(options.compact)
  format("t.%-*s %s", field_name_width, field_spec.type, args.join(', '))
end

#create_indexes(model) ⇒ Object 



297
298
299
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 297

def create_indexes(model)
  model.index_definitions.map { |i| i.to_add_statement(model.table_name) }
end

#create_table(model) ⇒ Object 



255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 255

def create_table(model)
  longest_field_name       = model.field_specs.values.map { |f| f.type.to_s.length }.max
  disable_auto_increment   = model.respond_to?(:disable_auto_increment) && model.disable_auto_increment
  table_options_definition = ::DeclareSchema::Model::TableOptionsDefinition.new(model.table_name, table_options_for_model(model))
  field_definitions        = [
    ("t.integer :id, limit: 8, auto_increment: false, primary_key: true" if disable_auto_increment),
    *(model.field_specs.values.sort_by(&:position).map { |f| create_field(f, longest_field_name) })
  ].compact

  <<~EOS.strip
    create_table :#{model.table_name}, #{create_table_options(model, disable_auto_increment)} do |t|
      #{field_definitions.join("\n")}
    end

    #{table_options_definition.alter_table_statement unless ActiveRecord::Base.connection.class.name.match?(/SQLite3Adapter/)}
    #{create_indexes(model).join("\n")               if ::DeclareSchema.default_generate_indexing}
    #{create_constraints(model).join("\n")           if ::DeclareSchema.default_generate_foreign_keys}
  EOS
end

#create_table_options(model, disable_auto_increment) ⇒ Object 



275
276
277
278
279
280
281
282
283
284
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 275

def create_table_options(model, disable_auto_increment)
  primary_key = model._defined_primary_key
  if primary_key.blank? || disable_auto_increment
    "id: false"
  elsif primary_key == "id"
    "id: :bigint"
  else
    "primary_key: :#{primary_key}"
  end
end

#default_collation_from_charset(charset) ⇒ Object 



545
546
547
548
549
550
551
552
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 545

def default_collation_from_charset(charset)
  case charset
  when "utf8"
    "utf8_general_ci"
  when "utf8mb4"
    "utf8mb4_general_ci"
  end
end

#drop_index(table, name) ⇒ Object 



439
440
441
442
443
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 439

def drop_index(table, name)
  # see https://hobo.lighthouseapp.com/projects/8324/tickets/566
  # for why the rescue exists
  "remove_index :#{table}, name: :#{name} rescue ActiveRecord::StatementInvalid"
end

#extract_column_renames!(to_add, to_remove, table_name) ⇒ Object 



136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 136

def extract_column_renames!(to_add, to_remove, table_name)
  if renames
    to_rename = {}
    if (column_renames = renames&.[](table_name.to_sym))
      # A hash of table renames has been provided

      column_renames.each_pair do |old_name, new_name|
        if to_add.delete(new_name.to_s) && to_remove.delete(old_name.to_s)
          to_rename[old_name.to_s] = new_name.to_s
        else
          raise Error, "Invalid rename specified: #{old_name} => #{new_name}"
        end
      end
    end
    to_rename

  elsif @ambiguity_resolver
    @ambiguity_resolver.call(to_add, to_remove, "column", "#{table_name}.")

  else
    raise Error, "Unable to resolve migration ambiguities in table #{table_name}"
  end
end

#extract_table_renames!(to_create, to_drop) ⇒ Object

return a hash of table renames and modifies the passed arrays so that renamed tables are no longer listed as to_create or to_drop



111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 111

def extract_table_renames!(to_create, to_drop)
  if renames
    # A hash of table renames has been provided

    to_rename = {}
    renames.each_pair do |old_name, new_name|
      new_name = new_name[:table_name] if new_name.is_a?(Hash)
      next unless new_name

      if to_create.delete(new_name.to_s) && to_drop.delete(old_name.to_s)
        to_rename[old_name.to_s] = new_name.to_s
      else
        raise Error, "Invalid table rename specified: #{old_name} => #{new_name}"
      end
    end
    to_rename

  elsif @ambiguity_resolver
    @ambiguity_resolver.call(to_create, to_drop, "table", nil)

  else
    raise Error, "Unable to resolve migration ambiguities"
  end
end

#fix_mysql_charset_and_collation(dumped_schema) ⇒ Object

TODO: rewrite this method to use charset and collation variables rather than manipulating strings. -Colin



574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 574

def fix_mysql_charset_and_collation(dumped_schema)
  if !dumped_schema['options: ']
    dumped_schema.sub!('",', "\", options: \"DEFAULT CHARSET=#{::DeclareSchema.default_charset} "+
      "COLLATE=#{::DeclareSchema.default_collation}\",")
  end
  default_charset   = dumped_schema[/CHARSET=(\w+)/, 1]   or raise "unable to find charset in #{dumped_schema.inspect}"
  default_collation = dumped_schema[/COLLATE=(\w+)/, 1] || default_collation_from_charset(default_charset) or
    raise "unable to find collation in #{dumped_schema.inspect} or charset #{default_charset.inspect}"
  dumped_schema.split("\n").map do |line|
    if line['t.text'] || line['t.string']
      if !line['charset: ']
        if line['collation: ']
          line.sub!('collation: ', "charset: #{default_charset.inspect}, collation: ")
        else
          line << ", charset: #{default_charset.inspect}"
        end
      end
      line['collation: '] or line << ", collation: #{default_collation.inspect}"
    end
    line
  end.join("\n")
end

#fk_field_options(model, field_name) ⇒ Object 



483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 483

def fk_field_options(model, field_name)
  foreign_key = model.constraint_specs.find { |fk| field_name == fk.foreign_key.to_s }
  if foreign_key && (parent_table = foreign_key.parent_table_name)
    parent_columns = connection.columns(parent_table) rescue []
    pk_limit =
      if (pk_column = parent_columns.find { |column| column.name.to_s == "id" }) # right now foreign keys assume id is the target
        if Rails::VERSION::MAJOR < 5
          pk_column.cast_type.limit
        else
          pk_column.limit
        end
      else
        8
      end

    { limit: pk_limit }
  else
    {}
  end
end

#format_options(options) ⇒ Object 



473
474
475
476
477
478
479
480
481
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 473

def format_options(options)
  options.map do |k, v|
    if k.is_a?(Symbol)
      "#{k}: #{v.inspect}"
    else
      "#{k.inspect} => #{v.inspect}"
    end
  end
end

#generate ⇒ Object 



180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 180

def generate
  models, db_tables = models_and_tables
  models_by_table_name = {}
  models.each do |m|
    if !models_by_table_name.has_key?(m.table_name)
      models_by_table_name[m.table_name] = m
    elsif m.superclass == models_by_table_name[m.table_name].superclass.superclass
      # we need to ensure that models_by_table_name contains the
      # base class in an STI hierarchy
      models_by_table_name[m.table_name] = m
    end
  end
  # generate shims for HABTM models
  habtm_tables.each do |name, refls|
    models_by_table_name[name] = ::DeclareSchema::Model::HabtmModelShim.from_reflection(refls.first)
  end
  model_table_names = models_by_table_name.keys

  to_create = model_table_names - db_tables
  to_drop = db_tables - model_table_names - self.class.always_ignore_tables
  to_change = model_table_names
  to_rename = extract_table_renames!(to_create, to_drop)

  renames = to_rename.map do |old_name, new_name|
    "rename_table :#{old_name}, :#{new_name}"
  end * "\n"
  undo_renames = to_rename.map do |old_name, new_name|
    "rename_table :#{new_name}, :#{old_name}"
  end * "\n"

  drops = to_drop.map do |t|
    "drop_table :#{t}"
  end * "\n"
  undo_drops = to_drop.map do |t|
    add_table_back(t)
  end * "\n\n"

  creates = to_create.map do |t|
    create_table(models_by_table_name[t])
  end * "\n\n"
  undo_creates = to_create.map do |t|
    "drop_table :#{t}"
  end * "\n"

  changes                    = []
  undo_changes               = []
  index_changes              = []
  undo_index_changes         = []
  fk_changes                 = []
  undo_fk_changes            = []
  table_options_changes      = []
  undo_table_options_changes = []

  to_change.each do |t|
    model = models_by_table_name[t]
    table = to_rename.key(t) || model.table_name
    if table.in?(db_tables)
      change, undo, index_change, undo_index, fk_change, undo_fk, table_options_change, undo_table_options_change = change_table(model, table)
      changes << change
      undo_changes << undo
      index_changes << index_change
      undo_index_changes << undo_index
      fk_changes << fk_change
      undo_fk_changes << undo_fk
      table_options_changes << table_options_change
      undo_table_options_changes << undo_table_options_change
    end
  end

  up = [renames, drops, creates, changes, index_changes, fk_changes, table_options_changes].flatten.reject(&:blank?) * "\n\n"
  down = [undo_changes, undo_renames, undo_drops, undo_creates, undo_index_changes, undo_fk_changes, undo_table_options_changes].flatten.reject(&:blank?) * "\n\n"

  [up, down]
end

#habtm_tables ⇒ Object

list habtm join tables



85
86
87
88
89
90
91
92
93
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 85

def habtm_tables
  reflections = Hash.new { |h, k| h[k] = [] }
  ActiveRecord::Base.send(:descendants).map do |c|
    c.reflect_on_all_associations(:has_and_belongs_to_many).each do |a|
      reflections[a.join_table] << a
    end
  end
  reflections
end

#load_rails_models ⇒ Object 



59
60
61
62
63
64
65
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 59

def load_rails_models
  ActiveRecord::Migration.verbose = false

  Rails.application.eager_load!
  Rails::Engine.subclasses.each(&:eager_load!)
  self.class.before_generating_migration_callback&.call
end

#models_and_tables ⇒ Object

Returns an array of model classes and an array of table names that generation needs to take into account



97
98
99
100
101
102
103
104
105
106
107
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 97

def models_and_tables
  ignore_model_names = Migrator.ignore_models.map { |model| model.to_s.underscore }
  all_models = table_model_classes
  declare_schema_models = all_models.select do |m|
    (m.name['HABTM_'] ||
      (m.include_in_migration if m.respond_to?(:include_in_migration))) && !m.name.underscore.in?(ignore_model_names)
  end
  non_declare_schema_models = all_models - declare_schema_models
  db_tables = connection.tables - Migrator.ignore_tables.map(&:to_s) - non_declare_schema_models.map(&:table_name)
  [declare_schema_models, db_tables]
end

#native_types ⇒ Object 



80
81
82
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 80

def native_types
  self.class.native_types
end

#remove_foreign_key(old_table_name, fk_name) ⇒ Object 



469
470
471
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 469

def remove_foreign_key(old_table_name, fk_name)
  "remove_foreign_key(#{old_table_name.inspect}, name: #{fk_name.to_s.inspect})"
end

#table_model_classes ⇒ Object

Returns an array of model classes that directly extend ActiveRecord::Base, excluding anything in the CGI module



69
70
71
72
73
74
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 69

def table_model_classes
  load_rails_models
  ActiveRecord::Base.send(:descendants).select do |klass|
    klass.base_class == klass && !klass.name.starts_with?("CGI::")
  end
end

#table_options_for_model(model) ⇒ Object 



286
287
288
289
290
291
292
293
294
295
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 286

def table_options_for_model(model)
  if ActiveRecord::Base.connection.class.name.match?(/SQLite3Adapter/)
    {}
  else
    {
      charset:   model.table_options[:charset] || ::DeclareSchema.default_charset,
      collation: model.table_options[:collation] || ::DeclareSchema.default_collation
    }
  end
end

#with_previous_model_table_name(model, table_name) ⇒ Object 



518
519
520
521
522
523
 
# File 'lib/generators/declare_schema/migration/migrator.rb', line 518

def with_previous_model_table_name(model, table_name)
  model_table_name, model.table_name = model.table_name, table_name
  yield
ensure
  model.table_name = model_table_name
end