Ruby-on-rails 验证附件内容类型回形针
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Validate Attachment Content Type Paperclip
提问by Kevin Sylvestre
Is it possible to enforce a 'content type' validation in paperclipwithout enforcing a 'presence' validation (i.e. allow blanks)? I currently have:
是否可以在不强制执行“存在”验证（即允许空白）的情况下在回形针中强制执行“内容类型”验证？我目前有：
class Person < ActiveRecord::Base
has_attached_file :picture
validates_attachment_content_type :picture, :content_type => ['image/jpeg', 'image/jpg', 'image/png']
end
However, this fails if no attachment is present. For example:
但是，如果不存在附件，这将失败。例如：
>> @person = Person.new
>> @person.save
>> @person.errors.first
=> ["picture_content_type", "is not one of image/jpeg, image/jpg, image/png"]
Is it possible to do the validation only if an attachment is included.
是否可以仅在包含附件的情况下进行验证。
回答by Jesse Wolgamott
I'm not sure that method is the cause of your failure; Here's my simple class
我不确定该方法是否是您失败的原因；这是我的简单课程
class Image < ActiveRecord::Base
has_attached_file :photo, {
:styles => { :large => "700x400#", :medium=>"490x368#", :thumbnail=>"75x75#" },
:default_url => "/images/thumbnail/blank-recipe.png"}
validates_attachment_content_type :photo, :content_type => /image/
end
Then, if I:
那么，如果我：
Image.new.valid?
#this is true
You might be doing other paperclip validations, though. Can you post a simple example?
不过，您可能正在进行其他回形针验证。你能贴一个简单的例子吗？
回答by mcls
Working example
工作示例
In the following model only image/png, image/gif and image/jpegare valid content types for the image attachment.
在以下模型中，只有image/png、image/gif 和 image/jpeg是图像附件的有效内容类型。
class Photo
has_attached_file :image
validates_attachment_content_type :image,
:content_type => /^image\/(png|gif|jpeg)/
end
Specs
眼镜
describe Photo do
it { should validate_attachment_content_type(:image).
allowing('image/png', 'image/gif', 'image/jpeg').
rejecting('text/plain', 'text/xml', 'image/abc', 'some_image/png') }
end
More info
更多信息
You could also take a look at the AttachmentContentTypeValidatorclass with is responsible for doing the validation.
您还可以查看负责进行验证的AttachmentContentTypeValidator类。
Or take a look at its testswhich contain more examples.
或者看看它包含更多示例的测试。
回答by Tim Snowhite
validates_content_type accepts :if => Proc.new{|r| !r.content_type.blank?}in it's options hash, perhaps that would solve your problem.
validates_content_type:if => Proc.new{|r| !r.content_type.blank?}在它的选项哈希中接受，也许这会解决你的问题。
回答by Bernard Banta
This worked for me;
这对我有用；
validates_attachment :image1, :presence => true,
:content_type => { :content_type => "image/jpg" },
:size => { :in => 0..10.kilobytes }
