Ever wanted to offer users the possibility to define their very own image sizes for uploaded pictures?<\/p>\n
Here’s how you can quickly do that.<\/p>\n
You will have a class acting as a an attachment such as:<\/p>\n
class AssetImage < ActiveRecord::Base\r\n\r\nhas_attachment :content_type => :image,\r\n:storage => :file_system,\r\n:max_size => 1.megabytes,\r\n:path_prefix => \"public\/system\/images\/#{ActiveRecord::Base.configurations[RAILS_ENV]['domain_name']}\/assets\/images\",\r\n:thumbnails => { :large => '450>', :normal => '300', :medium => '200', :thumbnail => [100,75] },\r\n:processor => :rmagick\r\n\r\nvalidates_as_attachment\r\n\r\n...<\/pre>\nFirst add a cattr_accessor to store your custom size in the class:<\/p>\n
cattr_accessor :custom_size<\/pre>\nNow, add a before_save callback which takes the assigned value and adds it to the list of requested image sizes. It is using the value as a minimum size while keeping aspect ratio.<\/p>\n
#store custom size\r\ndef before_save\r\n return if AssetImage.custom_size.nil?\r\n attachment_options[:thumbnails][:custom] = AssetImage.custom_size.to_s + \">\"\r\nend<\/pre>\nIn your controller do something like this: Take a value from your parameters and store it in your model to have your image customized.<\/p>\n
def add_image\r\n AssetImage.custom_size = params[:custom_size].to_i.to_s rescue \"100\"\r\n a = AssetImage.new(params[:asset_image])\r\n a.save\r\n redirect_to :action => :index\r\nend<\/pre>\n","protected":false},"excerpt":{"rendered":"Ever wanted to offer users the possibility to define their very own image sizes for uploaded pictures? Here’s how you can quickly do that. You will have a class acting as a an attachment such as: class AssetImage < ActiveRecord::Base has_attachment :content_type => :image, :storage => :file_system, :max_size => 1.megabytes, :path_prefix => “public\/system\/images\/#{ActiveRecord::Base.configurations[RAILS_ENV][‘domain_name’]}\/assets\/images”, :thumbnails => … <\/p>\n