module Sequel::Plugins

Empty namespace that plugins should use to store themselves, so they can be loaded via Model.plugin.

Plugins should be modules with one of the following conditions:

Constants

SEQUEL_METHOD_NAME

Return a unique method name symbol for the given suffix.

Public Class Methods

after_set_dataset(mod, meth) click to toggle source

Add method to mod that overrides set_dataset to call the method afterward.

Calls superclass method
# File lib/sequel/model/plugins.rb, line 46
def self.after_set_dataset(mod, meth)
  mod.send(:define_method, :set_dataset) do |*a|
    r = super(*a)
    # Allow calling private class methods as methods this specifies are usually private
    send(meth)
    r
  end
end
def_dataset_methods(mod, meths) click to toggle source

In the given module mod, define methods that are call the same method on the dataset. This is designed for plugins to define dataset methods inside ClassMethods that call the implementations in DatasetMethods.

This should not be called with untrusted input or method names that can't be used literally, since it uses class_eval.

# File lib/sequel/model/plugins.rb, line 31
def self.def_dataset_methods(mod, meths)
  Array(meths).each do |meth|
    mod.class_eval("def #{meth}(*args, &block); dataset.#{meth}(*args, &block) end", __FILE__, __LINE__)
  end
end
def_sequel_method(model, meth, expected_arity, &block) click to toggle source

Define a private instance method using the block with the provided name and expected arity. If the name is given as a Symbol, it is used directly. If the name is given as a String, a unique name will be generated using that string. The expected_arity should be either 0 (no arguments) or 1 (single argument).

If a block with an arity that does not match the expected arity is used, a deprecation warning will be issued. The method defined should still work, though it will be slower than a method with the expected arity.

Sequel only checks arity for regular blocks, not lambdas. Lambdas were already strict in regards to arity, so there is no need to try to fix arity to keep backwards compatibility for lambdas.

Blocks with required keyword arguments are not supported by this method.

# File lib/sequel/model/plugins.rb, line 77
def self.def_sequel_method(model, meth, expected_arity, &block)
  if meth.is_a?(String)
    meth = SEQUEL_METHOD_NAME.call(meth)
  end
  call_meth = meth

  unless block.lambda?
    required_args, optional_args, rest, keyword = _define_sequel_method_arg_numbers(block)

    if keyword == :required
      raise Error, "cannot use block with required keyword arguments when calling define_sequel_method with expected arity #{expected_arity}"
    end

    case expected_arity
    when 0
      unless required_args == 0
        # SEQUEL6: remove
        Sequel::Deprecation.deprecate("Arity mismatch in block passed to define_sequel_method. Expected Arity 0, but arguments required for #{block.inspect}. Support for this will be removed in Sequel 6.")
        b = block
        block = lambda{instance_exec(&b)} # Fallback
      end
    when 1
      if required_args == 0 && optional_args == 0 && !rest
        # SEQUEL6: remove
        Sequel::Deprecation.deprecate("Arity mismatch in block passed to define_sequel_method. Expected Arity 1, but no arguments accepted for #{block.inspect}.  Support for this will be removed in Sequel 6.")
        temp_method = SEQUEL_METHOD_NAME.call("temp")
        model.class_eval("def #{temp_method}(_) #{meth =~ /\A\w+\z/ ? "#{meth}_arity" : "send(:\"#{meth}_arity\")"} end", __FILE__, __LINE__)
        model.send(:alias_method, meth, temp_method)
        model.send(:undef_method, temp_method)
        model.send(:private, meth)
        meth = :"#{meth}_arity"
      elsif required_args > 1
        # SEQUEL6: remove
        Sequel::Deprecation.deprecate("Arity mismatch in block passed to define_sequel_method. Expected Arity 1, but more arguments required for #{block.inspect}.  Support for this will be removed in Sequel 6.")
        b = block
        block = lambda{|r| instance_exec(r, &b)} # Fallback
      end
    else
      raise Error, "unexpected arity passed to define_sequel_method: #{expected_arity.inspect}"
    end
  end

  model.send(:define_method, meth, &block)
  model.send(:private, meth)
  call_meth
end
inherited_instance_variables(mod, hash) click to toggle source

Add method to mod that overrides ::inherited_instance_variables to include the values in this hash.

Calls superclass method
# File lib/sequel/model/plugins.rb, line 39
def self.inherited_instance_variables(mod, hash)
  mod.send(:define_method, :inherited_instance_variables) do ||
    super().merge!(hash)
  end
end

Private Class Methods

_define_sequel_method_arg_numbers(callable) click to toggle source

Return the number of required argument, optional arguments, whether the callable accepts any additional arguments, and whether the callable accepts keyword arguments (true, false or :required).

# File lib/sequel/model/plugins.rb, line 128
def self._define_sequel_method_arg_numbers(callable)
  optional_args = 0
  rest = false
  keyword = false
  callable.parameters.map(&:first).each do |arg_type, _|
    case arg_type
    when :opt
      optional_args += 1
    when :rest
      rest = true
    when :keyreq
      keyword = :required
    when :key, :keyrest
      keyword ||= true
    end
  end
  arity = callable.arity
  if arity < 0
    arity = arity.abs - 1
  end
  required_args = arity
  arity -= 1 if keyword == :required

  if callable.is_a?(Proc) && !callable.lambda?
    optional_args -= arity
  end

  [required_args, optional_args, rest, keyword]
end