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资源说明：Add rating support to Rails apps with this plugin
has_ratings
===========
Instalation
-----------
1) Install the plugin with `script/plugin install git://github.com/fnando/has_ratings.git`
2) Generate a migration with `script/generate migration create_ratings` and add the following code:
class CreateRatings < ActiveRecord::Migration
def self.up
create_table :ratings do |t|
t.integer :rating, :default => 0, :null => false
t.references :rateable, :polymorphic => true
t.references :user
t.timestamps
end
add_index :ratings, :rateable_type
add_index :ratings, :rateable_id
add_index :ratings, :user_id
end
def self.down
drop_table :ratings
end
end
3) Add two columns on each model you're going to use `has_ratings`: `ratings_count` and `rating`
class AddRatingToPhoto < ActiveRecord::Migration
def self.up
add_column :photos, :ratings_count, :integer,
:default => 0, :null => false
add_column :photos, :rating, :float,
:precision => 3,
:scale => 2,
:default => 0,
:null => false
add_index :photos, :rating
add_index :photos, :ratings_count
end
def self.down
remove_index :photos, :rating
remove_column :photos, :rating
remove_index :photos, :ratings_count
remove_column :photos, :ratings_count
end
end
4) Run the migrations with `rake db:migrate`
Usage
-----
1) Add the method call `has_rating` to your model.
class Photo < ActiveRecord::Base
has_ratings
end
2) Add this association on your User model:
class User < ActiveRecord::Base
has_many :ratings
end
photo = Photo.find(:first)
user = User.find(:first)
photo.rate(:user => user, :rating => 1) # =>
photo.rated?(user) # => true
photo.ratings # => []
photo.rating! # => 0.0 (will skip rating cache)
photo.rating # => will use non-cached rating attribute
photo.ratings_count # => ratings count
photo.find_users_that_rated # => []
photo.find_rating_by_user(user) # =>
# retrieve best rated objects (order by rating desc)
Photo.best_rated # => []
# retrieve most rated objects (order by ratings_count desc)
Photo.most_rated # => []
If you have [has_paginate](http://github.com/fnando/has_paginate) installed,
you can paginate the users that rated a given item:
photo.find_users_that_rated(:page => 2)
Use this view helper to display the rating system:
<%= rating_stars photo, current_user, rate_photo_path(photo) %>
Is based on [this article](http://www.thebroth.com/blog/119). You can get the
stars image at . The CSS you need:
ul.rating {
width: 80px;
height: 16px;
margin: 0 10px 0 0;
padding: 0;
list-style: none;
float:left;
position: relative;
background: url(../images/stars.gif) no-repeat 0 0;
}
ul.zero { background-position: 0 0; }
ul.zero-half { background-position: 0 -16px; }
ul.one { background-position: 0 -32px; }
ul.one-half { background-position: 0 -48px; }
ul.two { background-position: 0 -64px; }
ul.two-half { background-position: 0 -80px; }
ul.three { background-position: 0 -96px; }
ul.three-half { background-position: 0 -112px; }
ul.four { background-position: 0 -128px; }
ul.four-half { background-position: 0 -144px; }
ul.five { background-position: 0 -160px; }
ul.rating li {
cursor: pointer;
float: left;
text-indent: -999em;
}
ul.rated li {
cursor: default;
}
ul.rating li a,
ul.rating li span {
position: absolute;
left: 0;
top: 0;
width: 16px;
height: 16px;
text-decoration: none;
z-index: 200;
}
ul.rating li.one a, ul.rating li.one span { left:0; }
ul.rating li.two a, ul.rating li.two span { left:16px; }
ul.rating li.three a, ul.rating li.three span { left:32px; }
ul.rating li.four a, ul.rating li.four span { left:48px; }
ul.rating li.five a, ul.rating li.five span { left:64px; }
ul.rating li a:hover {
z-index: 2;
width: 80px;
height: 16px;
overflow: hidden;
left: 0;
background: url(../images/stars.gif) no-repeat 0 0
}
ul.rating li.one a:hover { background-position:0 -176px; }
ul.rating li.two a:hover { background-position:0 -192px; }
ul.rating li.three a:hover { background-position:0 -208px; }
ul.rating li.four a:hover { background-position:0 -224px; }
ul.rating li.five a:hover { background-position:0 -240px; }
NOTE: You should have a User model. Otherwise, **this won't work**!
Copyright (c) 2008 Nando Vieira, released under the MIT license
本源码包内暂不包含可直接显示的源代码文件，请下载源码包。
