associate_jsonb

PostgreSQL JSONB extensions including:

• Basic ActiveRecord Associations using PostgreSQL JSONB columns, with built-in accessors and column indexes
• Thread-Safe JSONB updates (well, as safe as they can be) using a custom nested version of jsonb_set (jsonb_nested_set)

Requirements:

• PostgreSQL (>= 12)
• Rails 6.0.3.2

Usage

Jsonb Associations

jsonb_set based hash updates

When enabled, only keys present in the updated hash and with values changed in memory will be updated. To completely delete a key, value pair from an enabled attribute, set the key's value to nil.

e.g.

# given: instance#data == { "key_1"=>1,
#                           "key_2"=>2,
#                           "key_3"=> { "key_4"=>7,
#                                       "key_5"=>8,
#                                       "key_6"=>9 } }

instance.update({ key_1: "asdf", a: 1, key_2: nil, key_3: { key_5: nil }})
# instance#data => { "key_1"=>"asdf",
#                    "a"=>"asdf",
#                    "key_3"=> { "key_4"=>7,
#                                "key_6"=>9 } }

enabling/adding attribute types

first, create the sql function

rails g migration add_jsonb_nested_set_function

class CreateState < ActiveRecord::Migration[6.0]
  def up
    add_jsonb_nested_set_function
  end
end

then in an initializer, enable key based updates:

# config/initializers/associate_jsonb.rb
AssociateJsonb.enable_jsonb_set

Key based updates rely on inheritance for allowed attribute types. Any attributes that respond true to attr_type.is_a?(GivenClass) for any enabled type classes will use jsonb_nested_set

To add classes to the enabled list, pass them as arguments to AssociateJsonb.add_hash_type(*klasses). Any arguments passed to AssociateJsonb.enable_jsonb_set are forwarded to AssociateJsonb.add_hash_type

By default, calling AssociateJsonb.enable_jsonb_set(*klasses) without arguments, and no classes previously added, adds ActiveRecord::ConnectionAdapters::PostgreSQL::OID::Jsonb to the allowed classes list

disabling/removing attribute types

by default jsonb_nested_set updates are disabled.

if you've enabled them and need to disable, use: AssociateJsonb.disable_jsonb_set

To remove a class from the allowed list while leaving nested set updates enabled, use AssociateJsonb.remove_hash_type(*klasses). Any arguments passed to AssociateJsonb.disable_jsonb_set are forwarded to AssociateJsonb.remove_hash_type

Automatically delete nil value hash keys

When jsonb_set updates are disabled, jsonb columns are replaced with the current document (i.e. default rails behavior)

You are also given the option to automatically clear nil/null values from the hash automatically

in an initializer, enable stripping nil values:

# config/initializers/associate_jsonb.rb
AssociateJsonb.jsonb_delete_nil = true

Rules for classes to with this applies are the same as for jsonb_nested_set; add and remove classes through AssociateJsonb.(add|remove)_hash_type(*klasses)

License

The gem is available as open source under the terms of the MIT License.