Griddle: GridFileSystem made simple

Griddle is a file attachment gem for use with mongo-ruby-driver.

Installation

Install the gem:

gem install griddle

Usage

A class with a grid attachment:

class Document

  include Griddle::HasGridAttachment

  has_grid_attachment :image, :styles=>{
    :thumb => "50x50#"
  }

end

Or, alternately if you're using an object model

class Document

  include MongoMapper::Document
  include Griddle::HasGridAttachment

  has_grid_attachment :image, :styles=>{
    :thumb => "50x50#"
  }

end

Create a document:

@document = Document.new
@document.image = File.new("attached_file.jpg", 'rb')
@document.save_attached_files

Or, if you're using an object model, saved_attached_files is called after_save:

image = File.new("attached_file.jpg", 'rb')
@document = Document.new(:image => image)
@document.save

Retrieving A File

The contents of a file stored in GridFileSystem can be retrieved using Mongo::GridIO accessed by the file method:

@document.image.file
=> <#Mongo::GridIO>

@document.image.file.read
=> contents of file

Some other methods that may be helpful to know:

# does the attachment exist?
@document.image.exist?
=> true

# attachment file name
@document.image.file_name
=> attached_file.jpg

# attachment grid key
@document.image.grid_key
=> document/12345/image/attached_file.jpg

Styles

Griddle makes use of ImageMagik processor to fit and/or crop images and store different image styles:

@document.image.styles
=> {:thumb => '50x50#'}

Each style is saved as a Griddle::Attachment as well:

@document.image.thumb.exist?
=> true

@document.image.thumb.file_name
=> attached_file.jpg

@document.image.thumb.grid_key
=> documents/12345/images/attached_file.jpg

Note on Patches/Pull Requests