couchrest_model/lib/couchrest/model/designs.rb
2011-04-27 13:30:08 +02:00

91 lines
2.3 KiB
Ruby

#### NOTE Work in progress! Not yet used!
module CouchRest
module Model
# A design block in CouchRest Model groups together the functionality of CouchDB's
# design documents in a simple block definition.
#
# class Person < CouchRest::Model::Base
# property :name
# timestamps!
#
# design do
# view :by_name
# end
# end
#
module Designs
extend ActiveSupport::Concern
module ClassMethods
# Add views and other design document features
# to the current model.
def design(*args, &block)
mapper = DesignMapper.new(self)
mapper.create_view_method(:all)
mapper.instance_eval(&block) if block_given?
end
# Override the default page pagination value:
#
# class Person < CouchRest::Model::Base
# paginates_per 10
# end
#
def paginates_per(val)
@_default_per_page = val
end
# The models number of documents to return
# by default when performing pagination.
# Returns 25 unless explicitly overridden via <tt>paginates_per</tt>
def default_per_page
@_default_per_page || 25
end
end
#
class DesignMapper
attr_accessor :model
def initialize(model)
self.model = model
end
# Define a view and generate a method that will provide a new
# View instance when requested.
def view(name, opts = {})
View.create(model, name, opts)
create_view_method(name)
end
# Really simple design function that allows a filter
# to be added. Filters are simple functions used when listening
# to the _changes feed.
#
# No methods are created here, the design is simply updated.
# See the CouchDB API for more information on how to use this.
def filter(name, function)
filters = (self.model.design_doc['filters'] ||= {})
filters[name.to_s] = function
end
def create_view_method(name)
model.class_eval <<-EOS, __FILE__, __LINE__ + 1
def self.#{name}(opts = {})
CouchRest::Model::Designs::View.new(self, opts, '#{name}')
end
EOS
end
end
end
end
end