Resort provides sorting capabilities to your Rails 3 models.
$ gem install resort
Or in your Gemfile:
Most other sorting plugins work with an absolute
position attribute that sets
the weight of a given element within a tree. This field has no semantic sense,
since "84" by itself gives you absolutely no information about an element's
position or its relations with other elements of the tree.
Resort is implemented like a linked list,
rather than relying on absolute position values. This way, every model
next element, which seems a bit more sensible :)
You must add two fields (
first) to your model's table:
class AddResortFieldsToProducts < ActiveRecord::Migration def self.up add_column :products, :next_id, :integer add_column :products, :first, :boolean add_index :products, :next_id add_index :products, :first end def self.down remove_column :products, :next_id remove_column :products, :first end end
Then in your Product model:
class Product < ActiveRecord::Base resort! end
NOTE: By default, Resort will treat all products as a single big tree.
If you wanted to limit the tree scope, i.e. treating every ProductLine as a
separate tree of sortable products, you must override the
class Product < ActiveRecord::Base resort! def siblings # Tree contains only products from my own product line self.product_line.products end end
Multiple users modifying the same list at the same time could be a problem, so it's always a good practice to wrap the changes in a transaction:
Product.transaction do my_product.append_to(another_product) end
Every time a product is created, it will be appended after the last element.
Moreover, now a
product responds to the following methods:
first?— Returns true if the element is the first of the tree.
append_to(other_element)— Appends the element after another element.
And the class Product has a new scope named
ordered that returns the
products in order.
Under the hood
Run the test suite by typing:
You can also build the documentation with the following command:
Note on Patches/Pull Requests
- Fork the project.
- Make your feature addition or bug fix.
- Add tests for it. This is important so I don't break it in a future version unintentionally.
- Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
- Send us a pull request. Bonus points for topic branches.
Copyright (c) 2011 Codegram. See LICENSE for details.