Specifying missing.png in Paperclip

问题

I am using Paperclip to handle profile photo uploads in my app. They upload well and resize to the specifications in my model. However, if a User's profile :photo is nil, no matter what I try I can't change the default. Here's the code I want to use:

<% if @profile.photo.nil? %>
<%= image_tag "public/images/example.jpg", :html => { :id => "noUserProfile" } %>
<% else %>
<%= image_tag @profile.photo.url(:normal) %>
<% end %>

I've tried "../public/images/example.jpg" and that doesn't work either even though I have "example.jpg" in my public images folder. When I copy image address in my view, I get:

http://localhost:3000/photos/normal/missing.png

I added those folders to my app and put a missing.png file in there and nothing. If I go to the above URL I get No route matches "/photos/normal/missing.png"

Does anyone have any ideas as to what's going on?

has_attached_file in Profile model:

has_attached_file :photo,
  :styles => {
  :normal => "153x220#",
  :small => "75x108#" }

add_attachment_photo_to_profile migration:

class AddAttachmentPhotoToProfile < ActiveRecord::Migration
  def self.up
    add_column :profiles, :photo_file_name, :string
    add_column :profiles, :photo_content_type, :string
    add_column :profiles, :photo_file_size, :integer
    add_column :profiles, :photo_updated_at, :datetime
  end

  def self.down
    remove_column :profiles, :photo_file_name
    remove_column :profiles, :photo_content_type
    remove_column :profiles, :photo_file_size
    remove_column :profiles, :photo_updated_at
  end
end

This is the HTML that's rendered for when the :photo exists:

<div class="userSnapshot">
  <div class="smFrame">
    <div class="smUserPhoto">
      <img alt="8217_667699353137_15600054_38423586_7789442_n" src="/system/photos/1/small/8217_667699353137_15600054_38423586_7789442_n.jpg?1316052048" />
    </div>
  </div>
  <div class="findinfo">
    <p><a href="/profiles/1">Name</a></p>
  </div>
</div>

This is the HTML that's rendered for when the :photo is nil:

<div class="userSnapshot">
  <div class="smFrame">
    <div class="smUserPhoto">
      <img alt="Missing" src="/photos/small/missing.png" />
    </div>
  </div>
  <div class="findinfo">
    <p><a href="/profiles/2">Name</a></p>
  </div>
</div>

回答1:

Check out the :default_url option in the rdocs, that's why it's rendering as it is. Paperclip handles the cases when there's no attached file.

You can set the default to something different and avoid the extra work in your template.

回答2:

I think you want the exists? method.

if @profile.photo.exists?

@profile.photo.nil? will always be false because it returns the default image when it's missing.

NOTE: This checks if the really file exists, and can be very slow if you host your images on a CDN.

As a work around you might be able to just check if the database thinks there is a file:

if @profile.photo_file_name.present?

来源：https://stackoverflow.com/questions/7425001/specifying-missing-png-in-paperclip

标签

ruby-on-rails-3

paperclip