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

DEFAULT_CHARSET = 
"utf8mb4"
DEFAULT_COLLATION = 
"utf8mb4_bin"
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.



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 126

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.



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 87

def active_record_class
  @active_record_class
end

.before_generating_migration_callback ⇒ Object (readonly)

Returns the value of attribute before_generating_migration_callback.



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 87

def before_generating_migration_callback
  @before_generating_migration_callback
end

.default_charset ⇒ Object

Returns the value of attribute default_charset.



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 87

def default_charset
  @default_charset
end

.default_collation ⇒ Object

Returns the value of attribute default_collation.



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 87

def default_collation
  @default_collation
end

.disable_constraints ⇒ Object

Returns the value of attribute disable_constraints.



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 86

def disable_constraints
  @disable_constraints
end

.disable_indexing ⇒ Object

Returns the value of attribute disable_indexing.



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 86

def disable_indexing
  @disable_indexing
end

.ignore_models ⇒ Object

Returns the value of attribute ignore_models.



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 86

def ignore_models
  @ignore_models
end

.ignore_tables ⇒ Object

Returns the value of attribute ignore_tables.



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 86

def ignore_tables
  @ignore_tables
end

Instance Attribute Details

#renames ⇒ Object

Returns the value of attribute renames.



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 132

def renames
  @renames
end

Class Method Details

.always_ignore_tables ⇒ Object 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 235

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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 120

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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 116

def connection
  ActiveRecord::Base.connection
end

.default_migration_name ⇒ Object 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 110

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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 104

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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 599

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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 635

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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 609

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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 519

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'
  Migrator.disable_indexing and 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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 479

def change_indexes(model, old_table_name, to_remove)
  Migrator.disable_constraints and 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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 385

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.primary_key].nil? && model.primary_key.present?
  if model.primary_key.present?
    db_columns.delete(model.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.primary_key] if key_missing && model.primary_key.present?
  to_remove = db_column_names - model_column_names
  to_remove -= [model.primary_key.to_sym] if model.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.sql_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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 578

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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 151

def connection
  self.class.connection
end

#create_constraints(model) ⇒ Object 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 375

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

#create_field(field_spec, field_name_width) ⇒ Object 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 379

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.sql_type, args.join(', '))
end

#create_indexes(model) ⇒ Object 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 371

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

#create_table(model) ⇒ Object 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 330

def create_table(model)
  longest_field_name       = model.field_specs.values.map { |f| f.sql_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

  "    create_table :\#{model.table_name}, \#{create_table_options(model, disable_auto_increment)} do |t|\n      \#{field_definitions.join(\"\\n\")}\n    end\n\n    \#{table_options_definition.alter_table_statement unless ActiveRecord::Base.connection.class.name.match?(/SQLite3Adapter/)}\n    \#{create_indexes(model).join(\"\\n\")               unless Migrator.disable_indexing}\n    \#{create_constraints(model).join(\"\\n\")           unless Migrator.disable_indexing}\n  EOS\nend\n".strip

#create_table_options(model, disable_auto_increment) ⇒ Object 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 350

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

#default_collation_from_charset(charset) ⇒ Object 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 619

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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 513

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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 211

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



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 186

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



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 648

def fix_mysql_charset_and_collation(dumped_schema)
  if !dumped_schema['options: ']
    dumped_schema.sub!('",', "\", options: \"DEFAULT CHARSET=#{Generators::DeclareSchema::Migration::Migrator.default_charset} "+
      "COLLATE=#{Generators::DeclareSchema::Migration::Migrator.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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 557

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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 547

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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 255

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] = 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



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 160

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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 134

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



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 172

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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 155

def native_types
  self.class.native_types
end

#remove_foreign_key(old_table_name, fk_name) ⇒ Object 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 543

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



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 144

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 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 360

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

#with_previous_model_table_name(model, table_name) ⇒ Object 



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# File 'lib/generators/declare_schema/migration/migrator.rb', line 592

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