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# File 'lib/class_table_inheritance.rb', line 41
def has_extra_columns_from(options, &block)
table_name = options[:table]
primary_key_name = options[:foreign_key] || "#{name.demodulize.underscore}_id"
proxy_class_name = options[:proxy_class_name] || "ExtraColumnsFor#{table_name.camelize}"
proxy_class_namespace = (options[:proxy_class_namespace] || name).constantize
proxy_symbol = "extra_columns_for_#{table_name}".to_sym
proxy_class = proxy_class_namespace.const_get(proxy_class_name) rescue nil
unless proxy_class
proxy_class = proxy_class_namespace.const_set(proxy_class_name, Class.new(ActiveRecord::Base))
proxy_class.class_eval do
set_table_name table_name
set_primary_key primary_key_name
def self.reloadable?; false; end
end
proxy_class.class_eval(&block) if block_given?
end
has_one_without_cti proxy_symbol, :class_name => proxy_class.name, :foreign_key => primary_key_name, :dependent => :destroy
validates_associated proxy_symbol
if options[:save_before_superclass_callbacks] || true
proxy_save_callback = @inheritable_attributes[:after_save].pop
@inheritable_attributes[:after_create] ||= []
@inheritable_attributes[:after_create].unshift(proxy_save_callback)
@inheritable_attributes[:after_update] ||= []
@inheritable_attributes[:after_update].unshift(proxy_save_callback)
end
self.default_eager_loading = [proxy_symbol] unless options[:default_eager_loading] == false
class_eval <<-EOV
alias_method :#{proxy_symbol}_old, :#{proxy_symbol}
def #{proxy_symbol}
#{proxy_symbol}_old or self.#{proxy_symbol} = #{proxy_class.name}.new
end
def save(*args)
self.#{proxy_symbol} ||= #{proxy_class.name}.new
super
end
# this doesn't happen automatically on update, so we'll make it:
after_update {|record| record.#{proxy_symbol}.save }
alias_method :write_attribute_super, :write_attribute
def write_attribute(attr_name, attr_value)
if self.class.columns.find {|c| c.name == attr_name}
write_attribute_super(attr_name, attr_value)
else
self.#{proxy_symbol}.write_attribute(attr_name, attr_value)
end
end
alias_method :old_attributes, :attributes
def attributes
all_attributes = old_attributes.update(self.#{proxy_symbol}.attributes)
all_attributes.delete(#{proxy_class_name}.primary_key) if self.class.primary_key != #{proxy_class_name}.primary_key
all_attributes
end
class << self
alias_method :method_missing_super, :method_missing
def method_missing(method_symbol, *parameters)
if method_symbol.to_s =~ /^find_by_(.+)/
attributes = $1.split('_and_')
super_attributes = attributes & columns.map {|c| c.name}
sub_attributes = attributes - super_attributes
if super_attributes.size > 0
# TODO (uwe): Only use super attributes first
# then filter by sub_attributes
method_missing_super(method_symbol, *parameters)
else
result = #{proxy_class_name}.method_missing(method_symbol, parameters)
if result
if result.is_a? Array
result.map {|entry| entry.base}
else
result = result.base
end
else
result
end
end
else
method_missing_super(method_symbol, *parameters)
end
end
# TODO (uwe): validates_uniqueness_of should only be delegated for colimns not in super class???
delegate :validates_uniqueness_of, {:to => #{proxy_class_name}}
delegate :foreign_keys, {:to => #{proxy_class_name}}
end
EOV
delegate_methods = proxy_class.column_names
delegate_methods += proxy_class.column_names.map {|name| "#{name}=".to_sym }
delegate_methods += proxy_class.column_names.map {|name| "#{name}?".to_sym }
proxy_class.reflect_on_all_associations.each do |reflection|
delegate_methods += case reflection.macro
when :has_many, :has_and_belongs_to_many
[reflection.name, "#{reflection.name}=".to_sym, "#{reflection.name.to_s.singularize}_ids=".to_sym]
when :has_one
[reflection.name, "#{reflection.name}=".to_sym, "build_#{reflection.name}".to_sym, "create_#{reflection.name}".to_sym]
when :belongs_to
[reflection.name, "#{reflection.name}=".to_sym, "#{reflection.name}?".to_sym, "build_#{reflection.name}".to_sym, "create_#{reflection.name}".to_sym]
end
end
delegate(*(delegate_methods << {:to => proxy_symbol}))
proxy_class.belongs_to(:base, :class_name => options[:proxy_class_belongs_to], :foreign_key => primary_key_name) if options[:proxy_class_belongs_to]
if options[:delegate_new_associations]
class_eval <<-EOV
# associations on this subclass get added to the proxy class, and then the relevant methods delegated to the proxy object
def self.belongs_to(name, *params)
ExtraColumns.belongs_to(name, *params)
delegate name, "\#{name}=".to_sym, "\#{name}?".to_sym, "build_\#{name}".to_sym, "create_\#{name}".to_sym, :to => :#{proxy_symbol}
end
def self.has_one(name, *params)
ExtraColumns.has_one(name, *params)
delegate name, "\#{name}=".to_sym, "build_\#{name}".to_sym, "create_\#{name}".to_sym, :to => :#{proxy_symbol}
end
def self.has_many(name, *params)
ExtraColumns.has_many(name, *params)
delegate name, "\#{name}=".to_sym, "\#{name.to_s.singularize}_ids=".to_sym, :to => :#{proxy_symbol}
end
def self.has_and_belongs_to_many(name, *params)
ExtraColumns.has_and_belongs_to_many(name, *params)
delegate name, "\#{name}=".to_sym, "\#{name.to_s.singularize}_ids=".to_sym, :to => :#{proxy_symbol}
end
EOV
end
end
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