Module: ROM::Plugins::Relation::SQL::AutoRestrictions

Defined in:
lib/rom/plugins/relation/sql/auto_restrictions.rb

Overview

Generates methods for restricting relations by their indexed attributes

This plugin must be enabled for the whole adapter, use won’t work as schema is not yet available, unless it was defined explicitly.

Examples:

rom = ROM.container(:sql, 'sqlite::memory') do |config|
  config.create_table(:users) do
    primary_key :id
    column :email, String, null: false, unique: true
  end

  config.plugin(:sql, relations: :auto_restrictions)

  config.relation(:users) do
    schema(infer: true)
  end
end

# now `by_email` is available automatically
rom.relations[:users].by_email('[email protected]')

Constant Summary collapse

EmptySchemaError = 
Class.new(ArgumentError) do
  def initialize(klass)
    super("#{klass} relation has no schema. " \
          "Make sure :auto_restrictions is enabled after defining a schema")
  end
end

Class Method Summary collapse

Class Method Details

.included(klass) ⇒ Object

Raises:



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# File 'lib/rom/plugins/relation/sql/auto_restrictions.rb', line 36

def self.included(klass)
  super
  schema = klass.schema
  raise EmptySchemaError, klass if schema.nil?
  methods, mod = restriction_methods(schema)
  klass.include(mod)
  methods.each { |meth| klass.auto_curry(meth) }
end

.restriction_methods(schema) ⇒ Object 



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# File 'lib/rom/plugins/relation/sql/auto_restrictions.rb', line 45

def self.restriction_methods(schema)
  mod = Module.new

  indexed_attrs = schema.select { |attr| attr.meta[:index] }

  methods = indexed_attrs.map do |attr|
    meth_name = :"by_#{attr.name}"

    mod.module_eval do
      define_method(meth_name) do |value|
        where(attr.is(value))
      end
    end

    meth_name
  end

  [methods, mod]
end