To install attachment_fu
ruby script/plugin install http://svn.techno-weenie.net/projects/plugins/attachment_fu/
Then u need to design table in migration like
here we will take user images
class CreateUserImages < ActiveRecord::Migration
def self.up
create_table "user_images",:force => true do |t|
t.column "user_id", :integer
t.column "primary", :boolean
t.column "created_at", :datetime
# Required attributes for attachment_fu plugin
t.column "filename", :string, :limit => 255
t.column "path", :string, :limit => 255
t.column "content_type", :string
t.column "size", :integer
t.column "width", :integer
t.column "height", :integer
t.column "parent_id", :integer
t.column "thumbnail", :string
end
def self.down
drop_table :user_images
end
end
In model we need to customize validations
class UserImage < ActiveRecord::Base
belongs_to :user
has_attachment :content_type => :image,
:storage => :file_system,
:min_size => 0,
:max_size => 1.megabytes,
:resize_to => '640x480',
:thumbnails => { :medium => '200x200', :small => '80x80', :tiny => '40x40' }
# Override the default AttachmentFu error messages.
def validate
if filename.nil?
errors.add_to_base("You must choose a file to upload")
else
# Images should only be GIF, JPEG, or PNG
enum = attachment_options[:content_type]
unless enum.nil? || enum.include?(send(:content_type))
errors.add_to_base("You can only upload images (GIF, JPEG, or PNG)")
end
# Images should be less than UPLOAD_LIMIT MB.
enum = attachment_options[:size]
unless enum.nil? || enum.include?(send(:size))
msg = "Images should be smaller than 1 MB"
errors.add_to_base(msg)
end
end
end
end
And in User model
class User < ActiveRecord::Base
has_many :user_images
…
def primary_image
user_images.find_by_primary(true)
end
end
Here in controller only to display and create
class UserImagesController < ApplicationController
def new
@image = UserImage.new
respond_to do |format|
format.html
end
end
def create
# Required for Windows machines. Uncomment if you using Windows
# sleep(1)
user_data = {:user => current_user, :primary => current_user.images.empty? }
@image = UserImage.new(params[:image].merge(user_data))
respond_to do |format|
if @image.save
flash[:success] = "image successfully uploaded"
format.html { redirect_to(edit_user_path(current_user)) }
else
format.html { render :action => "new" }
end
end
end
end
And in new.rhtml
Current Primary Photo
<% if(@current_user.image.nil?) %>
<%= image_tag("default.png") %>
<% else %>
<%= image_tag(@current_user.primary_image.public_filename(:medium)) %>
<% end %>
Upload a new photo
<%= error_messages_for :image %>
<% form_for(:image, :url => user_images_path,
:html => { :multipart => true }) do |f| %>
Select a photo to upload
Photo: <%= f.file_field 'uploaded_data' %>
<%= submit_tag 'Upload Photo' %>
<% end %>
Follow the steps
Rake db:migrate
Then Script/server
If u want ur own validation to image then here are some key points
has_attachment(options = {})
* :size
o Range of sizes allowed.
o (1..1.megabyte) is the default. This overrides the :min_size and :max_size
* :resize_too Used by RMagick to resize images.
o Pass either an array of width/height, or a geometry string.
* :thumbnails
o Specifies a set of thumbnails to generate.
o This accepts a hash of filename suffixes and RMagick resizing options.
o This option need only be included if you want thumbnailing.
o :thumbnail_class
o Set which model class to use for thumbnails.o This current attachment class is used by default.
* :path_prefix
o path to store the uploaded files.
o path to store the uploaded files.
o Uses public/#{table_name} by default for the filesystem, and just #{table_name} for the S3 backend.
o Setting this sets the :storage to :file_system.
* :storage
o Specifies the storage system to use.
o Defaults to :db_file. Options are :file_system, :db_file, and :s3.
* :processor
o Sets the image processor to use for resizing of the attached image.
o Options include ImageScience, Rmagick, and MiniMagick. Default is whatever is installed.
* :content_type
o Allowed content types.
o Allows all by default. Use :image to allow all standard image types.
* :min_size
o Minimum size allowed.
o 1 byte is the default.
* :max_size
o Maximum size allowed.
o 1.megabyte is the default.
Reference link is: http://www.jumbabox.com/2008/06/attachment_fu-tutorial/
