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

classWidgetsController < ApplicationControllerdefindexrespond_todo |format|
format.csv{rendercsv: Widget.all}endenddefshowrespond_todo |format|
format.csv{rendercsv: Widget.find(params[:id])}endendend

By default, you don't need to change your models at all.

classWidget < ActiveRecord::Base# attributes :code, :description, :nameend

> 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.

classWidget < ActiveRecord::Base# attributes :code, :description, :namedefas_csv(options={})attributes.slice('name','code')endend

> 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:

classWidgetsController < ApplicationControllerrespond_to:csvdefindexrespond_withWidget.all,style: :shortendend

classWidget < ActiveRecord::Baseattr_accessible:code,:description,:namedefas_csv(options={})ifoptions[:style] == :shortattributes.slice('name','code')elseattributesendendend

Heterogenous Arrays

You can render any Array of objects that respond to as_csv.

classFoo < ActiveRecord::Base# attributes: name, description, codeend

classBar < ActiveRecord::Base# attributes: name, description, barcodeend

> 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

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Ensure you've got development dependencies: (bundle)
4. Ensure existing tests run: (bundle exec rspec)
5. Make your changes, including new specs
6. Commit your changes (git commit -am 'Add some feature')
7. Push to the branch (git push origin my-new-feature)
8. Create new Pull Request