asc_desc 
This gem adds two new methods to ActiveRecord (and ActiveRecord::Relation) that allows to sort SQL queries without using the "ASC" and "DESC" SQL keywords. It also adds a dynamic "order_by" mechanism (in the same way as dynamic finders).
Installation
Add to your Gemfile and run the bundle command to install it.
gem 'asc_desc'Requirements
- Ruby 1.8.7 or later
- Ruby on Rails 3.0 or later
Usage
asc
Call asc on an ActiveRecord object or on an ActiveRecord::Relation object to sort the column(s) in an ascending way.
# using a symbol for the name of the column
Candy.where(:sugar => true).asc(:name)
# using a string for the name of the column
Candy.where(:sugar => true).asc('name')
# using multiple parameters to specify more than one column for the sort clause
Candy.where(:sugar => true).asc(:classification, :name)
# using an array to pass mutliple arguments
Candy.where(:sugar => true).asc([:classification, :name])
# using a string to specify more than one column for the sort clause
Candy.where(:sugar => true).asc('classification, name')
# without argument, the method generates a sort by id (custom primary key supported)
# SELECT "candies".* FROM "candies" ORDER BY id ASC
Candy.where(:sugar => true).asc
# the method is chainable
Candy.where(:sugar => true).asc(:classification).asc(:name)ascending and ascending_order are aliases of asc.
desc
Call desc on an ActiveRecord object or on an ActiveRecord::Relation object to sort the column(s) in a descending way.
# using a symbol for the name of the column
Candy.where(:sugar => true).desc(:name)
# using a string for the name of the column
Candy.where(:sugar => true).desc('name')
# using multiple parameters to specify more than one column for the sort clause
Candy.where(:sugar => true).desc(:classification, :name)
# using an array to pass mutliple arguments
Candy.where(:sugar => true).desc([:classification, :name])
# using a string to specify more than one column for the sort clause
Candy.where(:sugar => true).desc('classification, name')
# without argument, the method generates a sort by id (custom primary key supported)
# SELECT "candies".* FROM "candies" ORDER BY id DESC
Candy.where(:sugar => true).desc
# the method is chainable
Candy.where(:sugar => true).desc(:classification).desc(:name)descending and descending_order are aliases of desc.
dynamic order_by
The dynamic order_by mechanism is built the same way as the dynamic finders present from the beginning of Ruby On Rails and allows to easely write the order clause for ActiveRecord queries.
# a call to order_by just acts like the standard built-in "order" method (alias)
Candy.where(:sugar => true).order_by('classification ASC, name ASC')
# using a column as part of the method name
Candy.where(:sugar => true).order_by_name
# using a column and a sort direction (asc|desc) as part of the method name
Candy.where(:sugar => true).order_by_name_asc
Candy.where(:sugar => true).order_by_name_desc
# using multiple columns as part of the method name
Candy.where(:sugar => true).order_by_classification_and_name
Candy.where(:sugar => true).order_by_classification_and_name_and_sugar
# using multiple columns and sort directions (asc|desc) as part of the method name
Candy.where(:sugar => true).order_by_classification_asc_and_name_desc
Candy.where(:sugar => true).order_by_classification_desc_and_name_asc
Candy.where(:sugar => true).order_by_classification_asc_and_name_desc_and_sugar_asc
# using multiple columns with or without sort direction (asc|desc) as part of the method name
Candy.where(:sugar => true).order_by_classification_and_name_desc
Candy.where(:sugar => true).order_by_classification_desc_and_name
```
## Development
Questions or problems? Please post them on the [issue tracker](https://github.com/dwerlen/asc_desc/issues).
You can contribute changes by forking the project and submitting a pull request.
You can ensure the tests passing by running `bundle` and `rake`.
This gem is created by David Werlen and is under the MIT License.
## Remark
`asc_desc` was developed in order to experiment the creation of a ruby gem.
It was conducted on the basis of the excellent tutorials from Ryan Bates, namely:
* ["#301 Extracting a Ruby Gem"](http://railscasts.com/episodes/301-extracting-a-ruby-gem)
* ["#303 Publishing a Gem"](http://railscasts.com/episodes/303-publishing-a-gem)