Supertach - the coolest and best Rails 3 attachment plugin

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Author:: Jonathan Bartlett

Copyright:: Copyright 2011 New Medio ( http://www.newmedio.com )

License:: Distributed under the same terms as ruby

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To setup Supertach, just do the following:

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rails plugin install [email protected]:johnnyb/supertach.git

rails generate supertach_initialize

rake db:migrate

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Supertach is a Rails 3 attachment plugin. It has many features to make your life better.

It doesn't require you to make a new class - it comes with one prepackaged - Attachment.

You just link to the attachment using an active record extension. See below for examples.

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Unlike other attachment programs, it does not require that you pre-specify thumbnail sizes.

Thumbnails are part of the view, and therefore to specify thumbnail sizes in model code is

over-mixing between the model and the view. In supertach, just call

attachment.thumbnail!(:width => 150) to get a 150-pixel thumbnail. Other attachment programs

require that you decide on a file storage mechanism up-front and then stick with it. It defaults

to local filesystem storage, but lets say that someone uploaded a 3-gig video that you think would

be better handled by S3. If you've named your s3 storage "s3", then you can do

attachment.migrate_storage!("s3") and viola! it's now served up from s3 instead of the filesystem.

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The big feature that is implemented is that Attachment is a class of it's own. You don't "add it"

to other classes the same way you would Attachment-fu or Paperclip. Instead, attachment is a

poly-polymorphic associate (yes, I made up that term) which allows for all sorts of coolness. Let's

say that I am selling homes, and my Home class needs to attachments - an interior photo and an exterior

photo. With Supertach, here's what you do:

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class Home < ActiveRecord::Base

has_one_attachment :interior_photo

has_one_attachment :exterior_photo

end

That's it!

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In addition, each attachment already comes with several generic fields that you can use for whatever

you like, including: name, description, url, and extra_data. You can use them or not use them, it's

your choice. If you choose not to use them, then it is super-easy to attach stuff:

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<%= form_for @home do |f| %>

<%= f.file_field :interior_photo_upload %>

<%= f.file_field :exterior_photo_upload %>

<% end %>

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Then to do the attaching, just use @home.update_attributes(params[:home])

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If you want to use them, the just use it as a regular has_one association, and set uploaded_data to

be the file upload, like this:

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class HomeController < ApplicationController

def whatever

@home = Home.find(params[:id])

data = params[:my_file_field]

@home.create_interior_photo(:name => "My Name", :description => "Blah", :uploaded_data => data)

end

end

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Not only that, but you can have collections of attachments. Let's say that instead of one interior

image, you wanted a bunch! Then, just do:

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class Home

has_many_attachments :interior_photos

has_one_attachment :exterior_photo

end

Now interior_photos acts just like a has_many relationship, but with attachments!

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Let's now display our attachments:

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<% @home = Home.find(params[:id]) %>

<% @home.interior_photos.each do |photo| %>

<%= photo.name %>:

<%= link_to(image_tag(photo.thumbnail!(:width => 50)), photo.public_url %>

<% end %>

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Another cool part of Supertach is the ability to manage representations (a thumbnail is

an example of a representation). Supertach

does not assume anything about a representation, or how you want it. You can do video,

image, sound, or any other kind of representations for files. The default representation

manager makes external calls out to ImageMagick for resizing widths. But, literally,

the representation manager is less than 20 lines long, so if it doesn't work for you,

you can easily replace it!

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To get the standard thumbnailer to work, be sure you have ImageMagick installed and in

the PATH used by your rails process. It does not require any external library at this time.