Module: DeclareSchema::Model::ClassMethods

Defined in:
lib/declare_schema/model.rb

Instance Method Summary collapse

Instance Method Details

#_declared_primary_key ⇒ Object

returns the primary key (String) as declared with primary_key = unlike the ‘primary_key` method, DOES NOT query the database to find the actual primary key in use right now if no explicit primary key set, returns the _default_declared_primary_key



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# File 'lib/declare_schema/model.rb', line 265

def _declared_primary_key
  if defined?(@primary_key)
    @primary_key&.to_s
  end || _default_declared_primary_key
end

#_infer_fk_limit(foreign_key_column, reflection) ⇒ Object 



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# File 'lib/declare_schema/model.rb', line 240

def _infer_fk_limit(foreign_key_column, reflection)
  if reflection.options[:polymorphic]
    if (foreign_key_column = columns_hash[foreign_key_column.to_s]) && foreign_key_column.type == :integer
      foreign_key_column.limit
    end
  else
    klass = reflection.klass or raise "Couldn't find belongs_to klass for #{name} in #{reflection.inspect}"
    if (pk_id_type = klass._table_options&.[](:id))
      if pk_id_type == :integer
        4
      end
    else
      if klass.table_exists? && (pk_column = klass.columns_hash[klass._declared_primary_key])
        pk_id_type = pk_column.type
        if pk_id_type == :integer
          pk_column.limit
        end
      end
    end
  end
end

#attr_type(name) ⇒ Object

Returns the type (a class) for a given field or association. If the association is a collection (has_many or habtm) return the AssociationReflection instead



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# File 'lib/declare_schema/model.rb', line 372

public \
def attr_type(name)
  if attr_types.nil? && self != self.name.constantize
    raise "attr_types called on a stale class object (#{self.name}). Avoid storing persistent references to classes"
  end

  attr_types[name] ||
    if (reflection = reflections[name.to_s])
      if reflection.macro.in?([:has_one, :belongs_to]) && !reflection.options[:polymorphic]
        reflection.klass
      else
        reflection
      end
    end ||
    if (col = _column(name.to_s))
      DeclareSchema::PLAIN_TYPES[col.type] || col.klass
    end
end

#belongs_to(name, scope = nil, **options) ⇒ Object

Extend belongs_to so that it

  1. creates a FieldSpec for the foreign key

  2. declares an index on the foreign key (optional)

  3. declares a foreign_key constraint (optional)

Other options are passed through to super

Parameters:

  • name (Symbol) —

    the name of the association to pass to super

  • scope (Proc) (defaults to: nil) —

    the scope of the association to pass to super

  • options (Hash) —

    a customizable set of options

Options Hash (**options):

  • :optional (Boolean) — default: default: false —

    whether the foreign key column should be nullable and whether ActiveRecord should validate presence of the foreign key (passed through to super)

  • :null (Boolean) — default: default: inferred from options[:optional] —

    whether the foreign key column should be nullable (‘null:` should only be passed if it is the inverse of `optional:`; otherwise it is redundant)

  • :limit (Integer) — default: default: inferred from the primary key limit: —

    the limit of the foreign key column size (4 or 8)

  • :index (Boolean|Hash<Symbol>) — default: default: true —

    whether to create an index on the foreign key; can be true or false or a hash of options to pass to the index declaration, with keys like { name: …, unique: … }

  • :allow_equivalent (Boolean) — default: default: false —

    whether to allow an existing index with a different name

  • :constraint (Boolean|String) — default: default: true —

    whether to create a foreign key constraint on the foreign key; may be true or false or a string to use as the constraint name

  • :polymorphic (Boolean) — default: default: false —

    whether this is a polymorphic belongs_to with a _type column next to the foreign key _id column (also passed through to super)

  • :far_end_dependent (Boolean) — default: default: nil —

    whether to add a dependent: :delete to the far end of the foreign key constraint

  • :foreign_type (String) — default: default: "#{name}_type" —

    the name prefix for the _type column for a polymorphic belongs_to (passed through to super)



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# File 'lib/declare_schema/model.rb', line 137

def belongs_to(name, scope = nil, **options)
  if options[:null].in?([true, false]) && options[:optional] == options[:null]
    STDERR.puts("[declare_schema warning] belongs_to #{name.inspect}, null: with the same value as optional: is redundant; omit null: #{options[:null]} (called from #{caller[0]})")
  elsif !options.has_key?(:optional)
    case options[:null]
    when true
      STDERR.puts("[declare_schema] belongs_to #{name.inspect}, null: true is deprecated in favor of optional: true (called from #{caller[0]})")
    when false
      STDERR.puts("[declare_schema] belongs_to #{name.inspect}, null: false is implied and can be omitted (called from #{caller[0]})")
    end
  end

  column_options = {}

  column_options[:null] = if options.has_key?(:null)
                            options.delete(:null)
                          elsif options.has_key?(:optional)
                            options[:optional] # infer :null from :optional
                          end || false
  column_options[:default] = options.delete(:default) if options.has_key?(:default)
  if options.has_key?(:limit)
    options.delete(:limit)
    ActiveSupport::Deprecation.warn("belongs_to #{name.inspect}, limit: is deprecated since it is now inferred")
  end

  # index: true means create an index on the foreign key
  # index: false means do not create an index on the foreign key
  # index: { ... } means create an index on the foreign key with the given options
  index_value = options.delete(:index)
  if index_value == false # don't create an index
    options.delete(:unique)
    options.delete(:allow_equivalent)
  else
    index_options = {} # create an index
    case index_value
    when String, Symbol
      ActiveSupport::Deprecation.warn("[declare_schema] belongs_to #{name.inspect}, index: 'name' is deprecated; use index: { name: 'name' } instead (in #{self.name})")
      index_options[:name] = index_value.to_s
    when true
    when nil
    when Hash
      index_options = index_value
    else
      raise ArgumentError, "[declare_schema] belongs_to #{name.inspect}, index: must be true or false or a Hash; got #{index_value.inspect} (in #{self.name})"
    end

    if options.has_key?(:unique)
      ActiveSupport::Deprecation.warn("[declare_schema] belongs_to #{name.inspect}, unique: true|false is deprecated; use index: { unique: true|false } instead (in #{self.name})")
      index_options[:unique] = options.delete(:unique)
    end

    index_options[:allow_equivalent] = options.delete(:allow_equivalent) if options.has_key?(:allow_equivalent)
  end

  constraint_name = options.delete(:constraint)

  dependent_delete = :delete if options.delete(:far_end_dependent) == :delete

  # infer :optional from :null
  if !options.has_key?(:optional)
    options[:optional] = column_options[:null]
  end

  super

  reflection = reflections[name.to_s] or raise "Couldn't find reflection #{name} in #{reflections.keys}"
  foreign_key_column = reflection.foreign_key or raise "Couldn't find foreign_key for #{name} in #{reflection.inspect}"
  foreign_key_column_options = column_options.dup

  # Note: the foreign key limit: should match the primary key limit:. (If there is a foreign key constraint,
  # those limits _must_ match.) We'd like to call _infer_fk_limit and get the limit right from the PK.
  # But we can't here, because that will mess up the autoloader to follow every belongs_to association right
  # when it is declared. So instead we assume :bigint (integer limit: 8) below, while also registering this
  # pre_migration: callback to double-check that assumption Just In Time--right before we generate a migration.
  #
  # The one downside of this approach is that application code that asks the field_spec for the declared
  # foreign key limit: will always get 8 back even if this is a grandfathered foreign key that points to
  # a limit: 4 primary key. It seems unlikely that any application code would do this.
  foreign_key_column_options[:pre_migration] = ->(field_spec) do
    if (inferred_limit = _infer_fk_limit(foreign_key_column, reflection))
      field_spec.sql_options[:limit] = inferred_limit
    end
  end

  declare_field(foreign_key_column.to_sym, :bigint, **foreign_key_column_options)

  if reflection.options[:polymorphic]
    foreign_type = options[:foreign_type] || "#{name}_type"
    _declare_polymorphic_type_field(foreign_type, column_options)
    if ::DeclareSchema.default_generate_indexing && index_options
      index([foreign_type, foreign_key_column], **index_options)
    end
  else
    if ::DeclareSchema.default_generate_indexing && index_options
      index([foreign_key_column], **index_options)
    end

    if ::DeclareSchema.default_generate_foreign_keys && constraint_name != false
      constraint(foreign_key_column, constraint_name: constraint_name || index_options&.[](:name), parent_class_name: reflection.class_name, dependent: dependent_delete)
    end
  end
end

#constraint(foreign_key_column, parent_table_name: nil, constraint_name: nil, parent_class_name: nil, dependent: nil) ⇒ Object 



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# File 'lib/declare_schema/model.rb', line 76

def constraint(foreign_key_column, parent_table_name: nil, constraint_name: nil, parent_class_name: nil, dependent: nil)
  constraint_definition = ::DeclareSchema::Model::ForeignKeyDefinition.new(
    foreign_key_column.to_s,
    constraint_name: constraint_name,
    child_table_name: table_name, parent_table_name: parent_table_name, parent_class_name: parent_class_name, dependent: dependent
  )

  constraint_definitions << constraint_definition # Set<> implements idempotent insert.
end

#declare_field(name, type, *args, **options) ⇒ Object

Declare named field with a type and an arbitrary set of arguments. The arguments are forwarded to the #field_added callback, allowing custom metadata to be added to field declarations.



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# File 'lib/declare_schema/model.rb', line 96

def declare_field(name, type, *args, **options)
  try(:field_added, name, type, args, options)
  _add_serialize_for_field(name, type, options)
  _add_formatting_for_field(name, type)
  _add_validations_for_field(name, type, args, options)
  _add_index_for_field(name, args, **options)
  field_specs[name] = ::DeclareSchema::Model::FieldSpec.new(self, name, type, position: field_specs.size, **options)
  attr_order << name unless attr_order.include?(name)
end

#ignore_index(index_name) ⇒ Object

tell the migration generator to ignore the named index. Useful for existing indexes, or for indexes that can’t be automatically generated.



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# File 'lib/declare_schema/model.rb', line 88

def ignore_index(index_name)
  ignore_indexes << index_name.to_s
end

#index(columns, name: nil, allow_equivalent: false, unique: false, where: nil, length: nil) ⇒ Object 



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# File 'lib/declare_schema/model.rb', line 52

def index(columns, name: nil, allow_equivalent: false, unique: false, where: nil, length: nil)
  index_definition = ::DeclareSchema::Model::IndexDefinition.new(
    columns,
    name: name, table_name: table_name, allow_equivalent: allow_equivalent, unique: unique, where: where, length: length
  )

  if (equivalent = index_definitions.find { index_definition.equivalent?(_1) }) # differs only by name
    if equivalent == index_definition
      # identical is always idempotent
    else
      # equivalent is idempotent iff allow_equivalent: true passed
      allow_equivalent or
        raise ArgumentError, "equivalent index definition found (pass allow_equivalent: true to ignore):\n" \
                             "#{index_definition.inspect}\n#{equivalent.inspect}"
    end
  else
    index_definitions << index_definition
  end
end

#index_definitions_with_primary_key ⇒ Object 



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# File 'lib/declare_schema/model.rb', line 106

def index_definitions_with_primary_key
  if index_definitions.any?(&:primary_key?)
    index_definitions
  else
    index_definitions + [_rails_default_primary_key]
  end
end

#primary_key_index(*columns) ⇒ Object 



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# File 'lib/declare_schema/model.rb', line 72

def primary_key_index(*columns)
  index(columns.flatten, unique: true, name: ::DeclareSchema::Model::IndexDefinition::PRIMARY_KEY_NAME)
end