Method: Blueprinter::Base.field

Defined in:

lib/blueprinter/base.rb

.field(method, options = {}) {|object, options| ... } ⇒ Field

Specify a field or method name to be included for serialization. Takes a required method and an option.

Examples:

Specifying a user’s first_name to be serialized.

class UserBlueprint < Blueprinter::Base
  field :first_name
  # other code
end

Passing a block to be evaluated as the value.

class UserBlueprint < Blueprinter::Base
  field :full_name do |object, options|
    "options[:title_prefix] #{object.first_name} #{object.last_name}"
  end
  # other code
end

Passing an if proc and unless method.

class UserBlueprint < Blueprinter::Base
  def skip_first_name?(_field_name, user, options)
    user.first_name == options[:first_name]
  end

  field :first_name, unless: :skip_first_name?
  field :last_name, if: ->(_field_name, user, options) { user.first_name != options[:first_name] }
  # other code
end

Parameters:

• method (Symbol) —

  the field or method name you want to include for serialization.

• options (Hash) (defaults to: {}) —

  options to overide defaults.

Options Hash (options):

• :extractor (AssociationExtractor, BlockExtractor, HashExtractor, PublicSendExtractor) —

  Kind of extractor to use. Either define your own or use Blueprinter’s premade extractors. The Default extractor is AutoExtractor

• :name (Symbol) —

  Use this to rename the method. Useful if if you want your JSON key named differently in the output than your object’s field or method name.

• :datetime_format (String, Proc) —

  Format Date or DateTime object If the option provided is a String, the object will be formatted with given strftime formatting. If this option is a Proc, the object will be formatted by calling the provided Proc on the Date/DateTime object.

• :if (Symbol, Proc) —

  Specifies a method, proc or string to call to determine if the field should be included (e.g. ‘if: :include_first_name?, or if: Proc.new { |_field_name, user, options| options == user }). The method, proc or string should return or evaluate to a true or false value.

• :unless (Symbol, Proc) —

  Specifies a method, proc or string to call to determine if the field should be included (e.g. ‘unless: :include_first_name?, or unless: Proc.new { |_field_name, user, options| options != user }). The method, proc or string should return or evaluate to a true or false value.

Yields:

• (object, options) —

  The object and the options passed to render are also yielded to the block.

Returns:

• (Field) —

  A Field object

# File 'lib/blueprinter/base.rb', line 122

def self.field(method, options = {}, &block)
  current_view << Field.new(
    method,
    options.fetch(:name) { method },
    options.fetch(:extractor) { Blueprinter.configuration.extractor_default.new },
    self,
    options.merge(block: block)
  )
end