instance method
has_json
Ruby on Rails edge
Since edgeSignature
has_json(attr, **schema)Provides a schema-enforced access object for a JSON attribute. This allows you to assign values directly from the UI as strings, and still have them set with the correct JSON type in the database.
Only the three basic JSON types are supported: boolean, integer, and string. No nesting either. These types can either be set by referring to them by their symbol or by setting a default value. Default values are set when a new model is instantiated and on before_save (if defined).
Examples:
class Account < ApplicationRecord
has_json :settings, restrict_creation_to_admins: true, max_invites: 10, greeting: "Hello!"
has_json :flags, beta: false, staff: :boolean
end
a = Account.new
a.settings.restrict_creation_to_admins? # => true
a.settings.max_invites = "100" # => Set to integer 100
a.settings = { "restrict_creation_to_admins" => "false", "max_invites" => "500", "greeting" => "goodbye" }
a.settings.greeting # => "goodbye"
a.flags.staff # => nil
a.flags.staff? # => false
Parameters
-
attrreq -
schemakeyrest
Source
# File activemodel/lib/active_model/schematized_json.rb, line 33
def has_json(attr, **schema)
define_method(attr) do
# Ensure the attribute is set if nil, so we can pass the reference to the accessor for defaults.
_write_attribute(attr.to_s, {}) if attribute(attr.to_s).nil?
# No memoization used in order to stay compatible with #reload (and because it's such a thin accessor).
ActiveModel::SchematizedJson::DataAccessor.new(schema, data: attribute(attr.to_s))
end
define_method("#{attr}=") { |data| public_send(attr).assign_data_with_type_casting(data) }
# Ensure default values are set before saving by relying on DataAccessor instantiation to do it.
before_save -> { send(attr) } if respond_to?(:before_save)
end
Defined in activemodel/lib/active_model/schematized_json.rb line 33
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Defined in ActiveModel::SchematizedJson::ClassMethods