Moving pagination to the Model

rubyonrails-talk
1

I'm using will_paginate in a Post class method;

[code]def self.list(page)   paginate :per_page => 10,            :page => page,            :include => :user end[/code]

I can happily use the method on my posts controller index action;

[code] class PostsController < ApplicationController

def index   @posts = Post.list(params[:page])

   respond_to do |format|      format.html # index.html.erb      format.js    end end [/code]

But I haven't worked out how to do it on my Users controller show action;

[code] class UsersController < ApplicationController

  def show     @user = User.find(params[:id])     @posts = @user.posts.paginate :per_page => 10,                                   :page => params[:page]   end [/code]

How I do I go about using the post.list class method on the post object within the @posts variable (therefore DRYing up the pagination and leaving it in the model)?

2

Neil wrote:

But I haven't worked out how to do it on my Users controller show action;

[code] class UsersController < ApplicationController

  def show     @user = User.find(params[:id])     @posts = @user.posts.paginate :per_page => 10,                                   :page => params[:page]   end [/code]

How I do I go about using the post.list class method on the post object within the @posts variable (therefore DRYing up the pagination and leaving it in the model)?

The 1 to many association between posts can users that AR builds for you (as an array) can be extended with :extend

check out ActiveRecord::Base::has_many() :extend

module PaginationExtension   def paginate     #your code here   end end

class User < ActiveRecord::Base   has_many :posts, :extend PaginationExtension end

@some_user.posts.paginate

hth

ilan

3

Thanks ilan. Just checked out the AP on associated extensions, but I have one question; where should I keep the PaginationExtension module? Posts are the only thing being paginated, so I presume I'd put the extension at the top of the post.rb. Is this correct? Or should I create a pagination_extension.rb?

4

Neil Cauldwell wrote:

Thanks ilan. Just checked out the AP on associated extensions, but I have one question; where should I keep the PaginationExtension module? Posts are the only thing being paginated, so I presume I'd put the extension at the top of the post.rb. Is this correct? Or should I create a pagination_extension.rb?

Should read 'Just checked out the API on associated extensions'.

5

Neil Cauldwell wrote:

Thanks ilan. Just checked out the AP on associated extensions, but I have one question; where should I keep the PaginationExtension module? Posts are the only thing being paginated, so I presume I'd put the extension at the top of the post.rb. Is this correct? Or should I create a pagination_extension.rb?

If that is the only model using it, then it's fine to keep it in that model file.. If on the other hand, it is to be used by more than one model then it should be in it's own file withing app/model or lib/

I like to embed my extension modules within the model itself as: class Foo < ActiveRecord::Base   module SomeExtension

6

Neil Cauldwell wrote:

module PaginationExtension   def pagination(page)     paginate :per_page => 10,              :page => page   end end

But I currently need to keep a class method on the Post.rb to keep it paginating on itself;

class Post < ActiveRecord::Base

  def self.pagination(page)     paginate :per_page => 10,              :page => page,              :include => :user   end

end

Any way round this?

class Post < ActiveRecord::Base

  module PaginationExtension     def pagination(page, options ={})       paginate {:per_page => 10,:page => page}.merge options     end   end

  has_many :whatevers, :extend => PaginationExtension

  extend PaginationExtension # no reason we can't extend it ourselves,   def pagination(page, options = {})     super(page, {:include => :user}.merge options   end

end

NOT TESTED,NOT TESTED.. use at your own risk.. I believe this may be a little drier and meets your criteria..

hth

ilan

7

Ilan Berci wrote:

Neil Cauldwell wrote:

module PaginationExtension   def pagination(page)     paginate :per_page => 10,              :page => page   end end

But I currently need to keep a class method on the Post.rb to keep it paginating on itself;

class Post < ActiveRecord::Base

  def self.pagination(page)     paginate :per_page => 10,              :page => page,              :include => :user   end

end

Any way round this?

class Post < ActiveRecord::Base

  module PaginationExtension     def pagination(page, options ={})       paginate {:per_page => 10,:page => page}.merge options     end   end

  has_many :whatevers, :extend => PaginationExtension

  extend PaginationExtension # no reason we can't extend it ourselves,   def pagination(page, options = {})     super(page, {:include => :user}.merge options   end

end

NOT TESTED,NOT TESTED.. use at your own risk.. I believe this may be a little drier and meets your criteria..

hth

ilan

My 'has_many :posts, :extend => PaginationExtension' lives in the User.rb, but the post model is the one being extended with pagination.

I tried putting 'module PaginationExtension' and the 'extend PaginationExtension' in the Post.rb whilst keeping the 'has_many :posts, :extend => PaginationExtension' in the User.rb, but I get a syntax error;

app/models/post.rb:5: syntax error, unexpected tASSOC, expecting '}'       paginate {:per_page => 10, :page => page}.merge options