Module: RESTFramework::Utils

Defined in:
lib/rest_framework/utils.rb

Constant Summary collapse

HTTP_VERB_ORDERING = 
%w[GET POST PUT PATCH DELETE OPTIONS HEAD]
FIELD_SPEC_KEYS =

A fields spec's structural (non-config) keys, i.e. those that shape set membership.

[ :only, :except, :include, :exclude, :config ].freeze

Class Method Summary collapse

Class Method Details

.association_fields_for(ref) ⇒ Object

Get the association's fields that may be serialized and filtered/ordered for a reflection.



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# File 'lib/rest_framework/utils.rb', line 187

def self.association_fields_for(ref)
  if !ref.polymorphic? && model = ref.klass
    fields = [ model.primary_key ].flatten.compact
    label_fields = RESTFramework.config.label_fields

    # Preferably find a database column to use as label.
    if match = label_fields.find { |f| f.in?(model.column_names) }
      return fields + [ match ]
    end

    # Otherwise, find a method.
    if match = label_fields.find { |f| model.method_defined?(f) }
      return fields + [ match ]
    end

    return fields
  end

  # A polymorphic association has no single target class, so we can't resolve a label column ahead
  # of time. The id and type together identify the record; a per-record label is added at
  # serialization time when the target has one (see `serialize_polymorphic`).
  [ "id", "type" ]
end

.comparable_path(path) ⇒ Object

Normalize a path pattern by replacing URL params with generic placeholder, and removing the (.:format) at the end.



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# File 'lib/rest_framework/utils.rb', line 18

def self.comparable_path(path)
  path.gsub("(.:format)", "").gsub(/:[0-9A-Za-z_-]+/, ":x")
end

.controller_for_model(current_controller, model) ⇒ Object

Find the REST controller for model at the same namespace level as current_controller, e.g. Api::Demo::MoviesController + Genre => Api::Demo::GenresController, or nil if none. The model match guards against trusting a same-named controller for a different model.



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# File 'lib/rest_framework/utils.rb', line 253

def self.controller_for_model(current_controller, model)
  return nil unless model && (base_name = current_controller.name)

  namespace = base_name.deconstantize
  model_name = model.model_name

  # Plural for a collection controller, singular for a singular-resource one.
  [ model_name.plural, model_name.singular ].each do |name|
    candidate_name = "#{name.camelize}Controller"
    candidate_name = "#{namespace}::#{candidate_name}" if namespace.present?

    candidate = candidate_name.safe_constantize
    next unless candidate.is_a?(Class) && candidate.include?(RESTFramework::Controller)
    next unless candidate.model == model

    return candidate
  end

  nil
end

.fields_for(model, exclude_associations:, action_text:, active_storage:) ⇒ Object

Get the fields for a given model, including not just columns (which includes foreign keys), but also associations. Note that we always return an array of strings, not symbols.



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# File 'lib/rest_framework/utils.rb', line 147

def self.fields_for(model, exclude_associations:, action_text:, active_storage:)
  belongs_to = model.reflect_on_all_associations(:belongs_to)

  # A polymorphic `belongs_to` is backed by both a foreign key and a `*_type` column; the
  # association represents both, so drop them from the plain column fields (as we already do for
  # every foreign key).
  excluded_columns = belongs_to.map(&:foreign_key)
  excluded_columns += belongs_to.select(&:polymorphic?).map(&:foreign_type)
  base_fields = model.column_names.reject { |c| c.in?(excluded_columns) }

  return base_fields if exclude_associations

  # ActionText Integration: Determine the normalized field names for action text attributes.
  atf = action_text ? model.reflect_on_all_associations(:has_one).collect(&:name).select { |n|
    n.to_s.start_with?("rich_text_")
  }.map { |n| n.to_s.delete_prefix("rich_text_") } : []

  # ActiveStorage Integration: Determine the normalized field names for active storage attributes.
  asf = active_storage ? model.attachment_reflections.keys : []

  # Associations:
  associations = model.reflections.map { |association, ref|
    # Ignore associations for which we have custom integrations.
    if ref.class_name.in?(%w[ActionText::RichText ActiveStorage::Attachment ActiveStorage::Blob])
      next nil
    end

    if ref.collection? && RESTFramework.config.large_reverse_association_tables&.include?(
      ref.table_name,
    )
      next nil
    end

    next association
  }.compact

  base_fields + associations + atf + asf
end

.get_request_route(application_routes, request) ⇒ Object

Get the first route pattern which matches the given request.



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# File 'lib/rest_framework/utils.rb', line 5

def self.get_request_route(application_routes, request)
  # Prefer the route already resolved by the router to avoid an expensive `recognize` call. This
  # is also required for Rails 8.1+ where OPTIONS routes are non-anchored, causing `path_info` to
  # be modified during dispatch, which makes `recognize` fail from inside the controller action.
  if route = request.env["action_dispatch.route"]
    return route
  end

  application_routes.router.recognize(request) { |route, _| return route }
end

.get_routes(application_routes, request, current_route: nil) ⇒ Object

Show routes under a controller action; used for the browsable API.



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# File 'lib/rest_framework/utils.rb', line 23

def self.get_routes(application_routes, request, current_route: nil)
  current_route ||= self.get_request_route(application_routes, request)
  current_path = current_route.path.spec.to_s.gsub("(.:format)", "")
  current_path = "" if current_path == "/"
  current_levels = current_path.count("/")
  current_comparable_path = %r{^#{Regexp.quote(self.comparable_path(current_path))}(/|$)}

  # Get current route path parameters.
  path_params = current_route.required_parts.map { |n| request.path_parameters[n] }

  # Return routes that match our current route subdomain/pattern, grouped by controller. We
  # precompute certain properties of the route for performance.
  application_routes.routes.select { |r|
    # We `select` first to avoid unnecessarily calculating metadata for routes we don't even want
    # to show.
    (r.defaults[:subdomain].blank? || r.defaults[:subdomain] == request.subdomain) &&
        current_comparable_path.match?(self.comparable_path(r.path.spec.to_s)) &&
        r.defaults[:controller].present? &&
        r.defaults[:action].present?
  }.map { |r|
    path = r.path.spec.to_s.gsub("(.:format)", "")

    # Starts at the number of levels in current path, and removes the `(.:format)` at the end.
    relative_path = path.split("/")[current_levels..]&.join("/").presence || "/"

    # This path is what would need to be concatenated onto the current path to get to the
    # destination path.
    concat_path = relative_path.gsub(/^[^\/]*/, "").presence || "/"

    levels = path.count("/")
    matches_path = current_path == path
    matches_params = r.required_parts.length == current_route.required_parts.length

    {
      route: r,
      verb: r.verb,
      path: path,
      path_with_params: r.format(
        r.required_parts.each_with_index.map { |p, i| [ p, path_params[i] ] }.to_h,
      ),
      relative_path: relative_path,
      concat_path: concat_path,
      controller: r.defaults[:controller].presence,
      action: r.defaults[:action].presence,
      matches_path: matches_path,
      matches_params: matches_params,
      # The following options are only used in subsequent processing in this method.
      _levels: levels,
    }
  }.sort_by { |r|
    [
      # Sort by levels first, so routes matching closely with current request show first.
      r[:_levels],
      # Then match by path, but manually sort ':' to the end using knowledge that Ruby sorts the
      # pipe character '|' after alphanumerics.
      r[:path].tr(":", "|"),
      # Finally, match by HTTP verb.
      HTTP_VERB_ORDERING.index(r[:verb]) || 99,
    ]
  }.group_by { |r| r[:controller] }.sort_by { |c, _r|
    # Sort the controller groups by current controller first, then alphanumerically.
    # Note: Use `controller_path` instead of `params[:controller]` to avoid re-raising a
    # `ActionDispatch::Http::Parameters::ParseError` exception.
    [ request.controller_class.controller_path == c ? 0 : 1, c ]
  }.to_h
end

.id_field_for(field, reflection) ⇒ Object

Get a field's id/ids variation.



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# File 'lib/rest_framework/utils.rb', line 238

def self.id_field_for(field, reflection)
  if reflection.collection?
    return "#{field.singularize}_ids"
  elsif reflection.belongs_to?
    # The id field for belongs_to is always the foreign key column name, even if the
    # association is named differently.
    return reflection.foreign_key
  end

  nil
end

.inflect(s, acronyms = nil) ⇒ Object

Custom inflector for RESTful controllers.



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# File 'lib/rest_framework/utils.rb', line 91

def self.inflect(s, acronyms = nil)
  acronyms&.each do |acronym|
    s = s.gsub(/\b#{acronym}\b/i, acronym)
  end

  s
end

.normalize_field_spec(spec) ⇒ Object

Normalize a field spec — an Array, a Hash, or nil — into a canonical {only:, include:, exclude:, config:} Hash containing only the keys that are present. A plain Array is sugar for only:. except: is an alias of exclude:; the two are merged.



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# File 'lib/rest_framework/utils.rb', line 105

def self.normalize_field_spec(spec)
  return {} if spec.nil?
  return { only: spec } unless spec.is_a?(Hash)

  exclude = (Array(spec[:exclude]) + Array(spec[:except])).presence
  { only: spec[:only], include: spec[:include], exclude: exclude, config: spec[:config] }.compact
end

.parse_fields_hash(h, model, exclude_associations:, action_text:, active_storage:) ⇒ Object

Resolve a top-level fields hash to an ordered array of string field names, using the model's default fields as the base. The config: key carries per-field configuration and is ignored for membership.



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# File 'lib/rest_framework/utils.rb', line 129

def self.parse_fields_hash(h, model, exclude_associations:, action_text:, active_storage:)
  base = model ? self.fields_for(
    model,
    exclude_associations: exclude_associations,
    action_text: action_text,
    active_storage: active_storage,
  ) : []

  # Warn for any unknown keys.
  (h.keys.map(&:to_sym) - FIELD_SPEC_KEYS).each do |k|
    Rails.logger.warn("RRF: Unknown key in fields hash: #{k}.")
  end

  self.resolve_field_names(h, base)
end

.resolve_field_names(spec, base) ⇒ Object

Resolve a field spec (Array | Hash | nil) to an ordered array of string field names: start from base unless only: replaces it, then apply include:. Any field named in config: is implicitly part of the set (so a configured field never needs to be listed twice). exclude: is applied last, so it can still drop a field that config:/include: would otherwise add.



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# File 'lib/rest_framework/utils.rb', line 117

def self.resolve_field_names(spec, base)
  spec = self.normalize_field_spec(spec)
  names = (spec[:only] || base).map(&:to_s)
  names += spec[:include].map(&:to_s) if spec[:include]
  names |= spec[:config].keys.map(&:to_s) if spec[:config]
  names -= spec[:exclude].map(&:to_s) if spec[:exclude]
  names
end

.serialize_polymorphic(target, type, fields = nil) ⇒ Object

Serialize a polymorphic association's target as {<pk> => id, "type" => type}, plus a label entry when the target responds to one of the configured label_fields. The type comes from the parent's *_type column, so it matches exactly what is stored (and what a reverse lookup uses).

fields are the association's configured fields. id/type are always emitted above; any other field is resolved against the target and included when it responds to it, so a field absent on a target class (e.g. price on a Genre) is omitted rather than serialized as nil.



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# File 'lib/rest_framework/utils.rb', line 218

def self.serialize_polymorphic(target, type, fields = nil)
  result = {}
  Array(target.class.primary_key).each { |pk| result[pk] = target.public_send(pk) }
  result["type"] = type

  if label = RESTFramework.config.label_fields.find { |f| target.respond_to?(f) }
    result[label.to_s] = target.public_send(label)
  end

  Array(fields).each do |f|
    f = f.to_s
    next if f.in?(%w[id type]) || result.key?(f)

    result[f] = target.public_send(f) if target.respond_to?(f)
  end

  result
end

.wrap_ams(s) ⇒ Object

Wrap a serializer with an adapter if it is an ActiveModel::Serializer.



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# File 'lib/rest_framework/utils.rb', line 275

def self.wrap_ams(s)
  if defined?(ActiveModel::Serializer) && (s < ActiveModel::Serializer)
    return RESTFramework::ActiveModelSerializerAdapterFactory.for(s)
  end

  s
end