Paperclip fails on a validates_presence_of

Question

Ok so i have a model and in that model i have

class User < ActiveRecord::Base
  validates_presence_of :name
  has_attached_file :picture, :styles => { :medium => "300x300>", :thumb => "100x100>",:tiny => "25x25>" }
end

when i create an user and upload a picture and not enter a name I get the expected message

1 error prohibited this user from being saved.
There were problems with the following fields:
    * Name can't be blank

But the image is gone...when i look at my console i see

        [paperclip] identify -format %wx%h '/var/folders/QK/QK+tCPT-Gx8yGDxVQbDuF++++TI/-Tmp-/stream20110113-19714-1ucz75p-0.jpg[0]' 2>/dev/null
        [paperclip] convert '/var/folders/QK/QK+tCPT-Gx8yGDxVQbDuF++++TI/-Tmp-/stream20110113-19714-1ucz75p-0.jpg[0]' -resize "25x25>" '/var/folders/QK/QK+tCPT-Gx8yGDxVQbDuF++++TI/-Tmp-/stream20110113-19714-1ucz75p-020110113-19714-r839l2-0' 2>/dev/null

but the image is gone on the new page....is there a way to preserve this image so anyone using the page doesnt have to browse for the image again

Answer 1

本文通过了以下过程： http: //ryantownsend.co.uk/articles/storing-paperclip-file-uploads-when-validation-fails.html就我个人而言，我还没有尝试过。

Answer 2

A better idea might be to add client-side validations to the form, so that if the user enters invalid data, they are immediately prompted to correct it. If you're only supporting IE10+, you can use HTML5 validations, otherwise you'll have to use Javascript validations.

Answer 3

Basically, no. This is browser behaviour that the server has no control over. If you're worried about validations elsewhere in your model causing the user to have to reselect and re-upload their images then I'd suggest making the file attachment a separate step.

Answer 4

The browser resets the form when they come back to it. You might be able to simulate something that looks like a single step by uploading the file using ajax in the background, and having javascripty goodness keep the form from submitting until the file is uploaded.