Posts Tagged ‘active record’

Rails Plugin Acts as Taggable on Steriods

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Posted 02 Mar 2010 — by admin
Category Ruby on Rails

You can download it here http://github.com/suitmymind/acts-as-taggable-on-steroids as well as read usage info (which is for the most part reprinted here). 

./script/plugin install http://svn.viney.net.nz/things/rails/plugins/acts_as_taggable_on_steroids
./script/generate acts_as_taggable_migration
rake db:migrate

Then in your model 

class Post < ActiveRecord::Base
    acts_as_taggable
 end

And usage is as follows

p = Post.find(:first)
p.tag_list # []
p.tag_list = "Funny, Silly"
p.save
p.tag_list # ["Funny", "Silly"]
p.tag_list.add("Great", "Awful")
p.tag_list.remove("Funny")

#to find...
Post.find_tagged_with('Funny, Silly')
Post.find_tagged_with('Funny, Silly', :match_all => true)

To use this in a form and let users enter a comma separated list of tag names... 

form_for @post do |f|
f.text_field :tag_list

And to get a tag cloud

  #controller
  class PostController < ApplicationController
    def tag_cloud
      @tags = Post.tag_counts
    end
  end

  # and in view...
  <style>
  .css1 { font-size: 1.0em; }
  .css2 { font-size: 1.2em; }
  .css3 { font-size: 1.4em; }
  .css4 { font-size: 1.6em; }
  </style>

  <% tag_cloud @tags, %w(css1 css2 css3 css4) do |tag, css_class| %>
    <%= link_to tag.name, { :action => :tag, :id => tag.name }, :class => css_class %>
  <% end %>

*Note. If you have a controller "tags_controller.rb" and the auto generated (if you used ./script/generate) helper file "tags_helper.rb" you'll need to make sure to copy the contents of the plugin lib module of the same name, into the helper file. You'll get an error otherwise.

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Descending Sort By in Model For Active Record Hash on Created_at attribute

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Posted 10 Nov 2009 — by admin
Category Ruby on Rails

If you have a couple collections from the database and you want to sort it without the help of Active Record, take a look at the sort_by method on Array type. I’ve used this before when I have a couple of collections which are slightly different but I need them in a chronological order.


  @posts_group_a = Post.find :all, :conditions => ["user_id = ?", current_user.id]
  @posts_group_b = Post.find :all, :conditions => ["user_id = ?", friend_user.id]

  #merge the two arrays here
  @posts = @posts_group_a + @posts_group_b

  # notice the "-" is for descending order and the "to_i" casts the date time to an integer (required)
  @posts.sort_by {|post| - post.created_at.to_i}
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Output Logger and SQL to the Rails Console in Development Mode

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Posted 10 Nov 2009 — by admin
Category Ruby on Rails

If you want to take a look at the SQL being generated by active record while your using the console, you can either type this into the console when it loads

ActiveRecord::Base.logger = Logger.new(STDOUT)

Or you can add it to your environment so that it’ll be the default behavior
rails_root/config/environments/development.rb

#...
ActiveRecord::Base.logger = Logger.new(STDOUT)

It’s a nice way to keep you away of any expensive queries you may unknowingly be writing!

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Acts_as_versioned Rails Plugin

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Posted 17 Sep 2009 — by admin
Category Ruby on Rails

Versioning models with the acts_as_versioned plugin

cd rails/app
./script/plugin install git://github.com/technoweenie/acts_as_versioned.git
./script/generate model post title:string body:text

In your model

class Post < ActiveRecord::Base
  acts_as_versioned
end

In db/migrate/****_create_posts.rb

  def self.up
    create_table :posts do |t|
      t.string :title
      t.text :body
      t.timestamps
    end
    Post.create_versioned_table
  end

  def self.down
    drop_table :posts
    Post.drop_versioned_table
  end

Migrate your db

rake db:migrate

Usage

p = Post.create :body => "hello world"
p.body = "HELLO WORLD"
p.save

p.versions.size
p.versions.last
p.revert_to(p.versions.first)
p.body # => hello world

*Quick Note If you want to revert to an older version in a controller or something, don't do 

@post = @post.revert_to(2)

Revert_to method will return a TrueClass, Boolean type. Instead use

@post.revert_to(2)

This method will update the attributes for you and when you call them you'll get that version.

More information is available here http://ar-versioned.rubyforge.org/ and http://www.urbanhonking.com/ideasfordozens/archives/2006/02/learns_to_use_a_1.html

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