Module: Sequel::Plugins::DefaultsSetter

Defined in:

lib/sequel/plugins/defaults_setter.rb

Overview

The defaults_setter plugin makes the column getter methods return the default values for new objects, if the values have not already been set. Example:

# column a default NULL
# column b default 2
album = Album.new
album.a # => nil
album.b # => 2
album = Album.new(a: 1, b: 3)
album.a # => 1
album.b # => 3

You can manually set default values as well:

Album.default_values[:a] = 4
Album.new.a # => 4

You can also provide procs to set default values:

Album.default_values[:a] = lambda{Date.today}
Album.new.a # => Date.today

If the proc accepts a single argument, it is passed the instance, allowing default values to depend on instance-specific state:

Album.default_values[:a] = lambda{|album| album.b + 1}
Album.new(b: 10).a # => 11

By default, default values returned are not cached:

Album.new.a.equal?(Album.new.a) # => false

However, you can turn on caching of default values:

Album.plugin :defaults_setter, cache: true
Album.new.a.equal?(Album.new.a) # => false

Note that if the cache is turned on, the cached values are stored in the values hash:

Album.plugin :defaults_setter, cache: true
album = Album.new
album.values # => {}
album.a
album.values # => {:a => Date.today}

Usage:

# Make all model subclass instances set defaults (called before loading subclasses)
Sequel::Model.plugin :defaults_setter

# Make the Album class set defaults
Album.plugin :defaults_setter

Defined Under Namespace

Modules: ClassMethods, InstanceMethods

Class Method Summary

• .configure(model, opts = OPTS) ⇒ Object

  Set the default values based on the model schema.

Class Method Details

.configure(model, opts = OPTS) ⇒ Object

Set the default values based on the model schema. Options:

:cache

Cache default values returned in the model’s values hash.

# File 'lib/sequel/plugins/defaults_setter.rb', line 63

def self.configure(model, opts=OPTS)
  model.instance_exec do
    set_default_values
    @cache_default_values = opts[:cache] if opts.has_key?(:cache)
  end
end