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# frozen-string-literal: true
module Sequel
module Plugins
# The update_refresh plugin makes the model class refresh
# the object after updating. By default, Sequel only
# refreshes automatically after inserting new rows, not
# after updating. However, if you are using triggers
# to modify the contents of updated rows, it can be
# helpful to immediately get the current data after
# updating.
#
# If the dataset supports UPDATE RETURNING, this
# plugin will use it so that it can retrieve the current
# data in the same query it uses for the update.
#
# Usage:
#
# # Make all model subclasses refresh after update
# Sequel::Model.plugin :update_refresh
#
# # Make the Album class refresh after update
# Album.plugin :update_refresh
#
# As a performance optimisation, if you know only specific
# columns will have changed, you can specify them to the
# +columns+ option. This can be a performance gain if it
# would avoid pointlessly comparing many other columns.
# Note that this option currently only has an effect if the
# dataset supports RETURNING.
#
# # Only include the artist column in RETURNING
# Album.plugin :update_refresh, columns: :artist
#
# # Only include the artist and title columns in RETURNING
# Album.plugin :update_refresh, columns: [:artist, :title]
module UpdateRefresh
# Set the specific columns to refresh, if the :columns option
# is provided.
def self.configure(model, opts=OPTS)
model.instance_exec do
@update_refresh_columns = Array(opts[:columns]) || []
end
end
module ClassMethods
# The specific columns to refresh when updating, if UPDATE RETURNING is supported.
attr_reader :update_refresh_columns
# Freeze the update refresh columns when freezing the model class.
def freeze
@update_refresh_columns.freeze
super
end
end
module InstanceMethods
# If the dataset does not support UPDATE RETURNING, then refresh after an update.
def after_update
super
unless this.supports_returning?(:update)
refresh
end
end
private
# If the dataset supports UPDATE RETURNING, use it to do the refresh in the same
# query as the update.
def _update_without_checking(columns)
ds = _update_dataset
if ds.supports_returning?(:update)
ds = ds.opts[:returning] ? ds : ds.returning(*self.class.update_refresh_columns)
rows = ds.update(columns)
n = rows.length
if n == 1
@values.merge!(rows.first)
end
n
else
super
end
end
end
end
end
end
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