AsCSV
This gem allows you to expose CSV in your apps as you'd expose JSON or XML.
Rails is not strictly required, but currently the magic only works with Rails > 3.x.x.
Installation
Add this line to your application's Gemfile:
gem 'as_csv', '~> 3.0'Basic Usage
Simply render CSV in a controller
class WidgetsController < ApplicationController
def index
respond_to do |format|
format.csv { render csv: Widget.all }
end
end
def show
respond_to do |format|
format.csv { render csv: Widget.find(params[:id]) }
end
end
endBy default, you don't need to change your models at all.
class Widget < ActiveRecord::Base
# attributes :code, :description, :name
end> puts Widget.all.to_csv
id,name,description,code
1,widget-1,widget-description-1,1001
2,widget-2,widget-description-2,1002
3,widget-3,widget-description-3,1003
4,widget-4,widget-description-4,1004
=> nil
> puts Widget.where(code: [1001, 1002]).to_csv
id,name,description,code
1,widget-1,widget-description-1,1001
2,widget-2,widget-description-2,1002
> puts Widget.first.to_csv
id,name,description,code
1,widget-1,widget-description-1,1001
=> nil
Behind the scenes, any classes that include ActiveModel::Serialization will expose their attributes with to_csv.
Advanced Usage
Customizing the CSV
To change what's included in the CSV, define an as_csv method. This method must return a Hash.
class Widget < ActiveRecord::Base
# attributes :code, :description, :name
def as_csv(options={})
attributes.slice('name', 'code')
end
end> puts Widget.all.to_csv
name,code
widget-1,1001
widget-2,1002
widget-3,1003
widget-4,1004
=> nil
>
You can also accept options:
class WidgetsController < ApplicationController
respond_to :csv
def index
respond_with Widget.all, style: :short
end
endclass Widget < ActiveRecord::Base
attr_accessible :code, :description, :name
def as_csv(options={})
if options[:style] == :short
attributes.slice('name', 'code')
else
attributes
end
end
endHeterogenous Arrays
You can render any Array of objects that respond to as_csv.
class Foo < ActiveRecord::Base
# attributes: name, description, code
endclass Bar < ActiveRecord::Base
# attributes: name, description, barcode
end> puts (Foo.all + Bar.all).to_csv
name,description,code,barcode
foo1,foo1-description,111,
foo2,foo2-description,222,
bar1,bar1-description,,acb12345
bar2,bar2-description,,xyz98765
Stdlib CSV options
If you need to pass any options to the underlying CSV library:
> puts (Foo.all + Bar.all).to_csv csv_options: {col_sep:'|'}
name|description|code|barcode
foo1|foo1-description|111|
foo2|foo2-description|222|
bar1|bar1-description||acb12345
bar2|bar2-description||xyz98765
Contributing
- Fork it
- Create your feature branch (
git checkout -b my-new-feature) - Ensure you've got development dependencies: (
bundle) - Ensure existing tests run: (
bundle exec rspec) - Make your changes, including new specs
- Commit your changes (
git commit -am 'Add some feature') - Push to the branch (
git push origin my-new-feature) - Create new Pull Request