.gitignore spec/from_param_spec.rb spec/schema.rb spec/spec_helper.rb @@ -1,11 +1,17 @@ FromParam ========= -This plugin is a tiny addition to ActiveRecord::Base that establishes a better +This plugin is an addition to ActiveRecord::Base that establishes a better convention for finding records based on parameters. It adds a "from_param" class method to ActiveRecord::Base as a convention for fetching a model from a URL parameter. By default it will find a record based on the to_i of the passed in -parameter, but the real use is by overriding it. +parameter, but storing a parameter in a column is where it becomes especially useful. + +If you create a 'param' column in your table (or any other column using set_param_column), +the to_param of your record will automatically be saved to that column whenever +you save the record, and you will be able to retrieve it using just a simple +Model.from_param call with the generated to_param. It is probably wise to add an index +to the param column if you use one. It's time to move away from generated-key-dependence, and this plugin is an attempt to make that easy, painless, and work easily within the existing systems. @@ -16,31 +22,35 @@ Example # default behavior class User < ActiveRecord::Base - + def to_param + "#{id}-#{first_name.downcase}-#{last_name.downcase}" + end end class UsersController < ApplicationController - # GET /users/1 + # GET /users/1-bobby-mcfarin def show - @user = User.from_param(params[:id]) # => <User id=1 login=mbleigh> + @user = User.from_param(params[:id]) # => <User id=1 first_name="Bobby" last_name="McFarin"> end end - # overriding + # using a 'param' column, in this case 'slug' - class User < ActiveRecord::Base + class Post < ActiveRecord::Base + set_param_column "slug" # defaults to "param" def to_param - login - end - - def self.from_param(parameter) - User.find_by_login(parameter) + "#{created_at.strftime("%Y-%m-%d")}-#{title.gsub(" ","-").downcase.gsub(/[^a-z0-9-]/,"")}" end end - class UsersController < ApplicationController - # GET /users/mbleigh - @user = User.from_param(params[:id]) # => <User id=1 login=mbleigh> + class PostsController < ApplicationController + # GET /posts/2008-04-26-from-param-plugin-released + @post = Post.from_param(params[:id]) # => <Post title="From Param: Plugin Released" created_at="2008-04-26"> end + +Resources +========= + +Lighthouse: Copyright (c) 2008 Michael Bleigh, released under the MIT license README @@ -1,2 +1 @@ -require 'from_param' -ActiveRecord::Base.send :include, FromParam \ No newline at end of file +require 'from_param' \ No newline at end of file init.rb @@ -1,11 +1,52 @@ -module FromParam - def self.included(base) - base.extend ClassMethods - end - - module ClassMethods +class ActiveRecord::Base + # Class Methods + class << self + # The column that is currently set to be used with + # the from_param method. + def param_column + "param" + end + alias :param_column= :param_column + + # Allows you to set the column that will be used + # by from_param by default. + def set_param_column(val) + define_attr_method :param_column, val + end + + # Returns true if the param_column is one of the + # currently defined columns of your table. + def param_column? + column_names.include?(param_column) + end + + # Takes a parameter generated by to_param and + # tried to find a matching record. If param_column + # is set and exists, uses that as the finder, otherwise + # uses the id such as in the default Rails to_param. def from_param(parameter) - find(parameter.to_i) + if param_column? + send "find_by_#{param_column}", parameter + else + find_by_id(parameter.to_i) + end end end + + # Calls param_column? on the class + def param_column? + self.class.param_column? + end + + # Calls param_column on the class + def param_column + self.class.param_column + end + + before_save :set_param + # Automatically called before saving, sets + # the param_column to the current to_param + def set_param + send "#{param_column}=", to_param if param_column? + end end \ No newline at end of file lib/from_param.rb 722c4c7b276501ff3db10f2a59b0d197f9f7e59f Michael Bleigh michael@intridea.com http://github.com/ffmike/from_param/commit/0317cb7e6e089d3bfd18546a353fc577c232a4b0 0317cb7e6e089d3bfd18546a353fc577c232a4b0 2008-04-26T20:10:57-07:00 2008-04-26T20:10:57-07:00 Complete rewrite to include automatic storing and retrieval from a 'param' column along with the default functionality. Should make parameterizing models a snap! 14751cf6c4ff2bdfe4ec91521de8a87dc711f093 Michael Bleigh michael@intridea.com