如果contenttype是image,如何设置Paperclip样式？

Question

我使用以下内容:

has_attached_file :file,:styles => { :thumbnail => '320x240!'},:url => "/images/:attachment/:id/:style/:basename.:extension",:path => ":rails_root/public/images/:attachment/:id/:style/:basename.:extension"

validates_attachment_content_type :file, :content_type => [ 'image/gif', 'image/png', 'image/x-png', 'image/jpeg', 'image/pjpeg', 'image/jpg' ]

上传图片和视频.如果我使用:style =>{}那么图像不上传.我想:style只在文件的内容类型是图像时才使用方法.

Answer 1

你可以在lambda中使用condition,抱歉丑陋的格式:

has_attached_file :file, :styles => lambda 
{ |a| 
      if a.instance.is_image?
        {:thumbnail => "320x240!"}
      end
}


def is_image?
    return false unless asset.content_type
    ['image/jpeg', 'image/pjpeg', 'image/gif', 'image/png', 'image/x-png', 'image/jpg'].include?(asset.content_type)
end