在 ruby rails 上通过回形针根据用户名的第一个字符添加缺失的图像

Question

我使用回形针gem上传和显示图片。

我想根据用户名字的第一个字符显示丢失的图像。假设用户名是 "Foo"，丢失的图像上应该显示字母 F。

同样，如果用户的名字是 "Bar"，丢失的图像应该是带有字母 "B" 的图像。通用缺失图像工作正常。我有所有 26 张图片，上面有 26 个单独的字母。谁能帮忙。这是我在用户模型中的代码。

 has_attached_file :avatar, styles: { medium: "300x300", thumb: "100x100", small: "50x50", mini: "25x25>", xsmall: "15x15" },
                default_url: ":style/missingdp.jpeg",
                url: "/assets/users/:id/:style/:basename.:extension",
                path: ":rails_root/public/assets/users/:id/:style/:basename.:extension"
 validates_attachment_content_type :avatar, { content_type: ["image/jpeg", "image/jpg", "image/gif", "image/png"] }
 validates_attachment_size :avatar, less_than: 3.megabytes

Answer 1

您需要一种方法来查看它们是否有缩略图，如果没有，则为它们选择合适的缺失缩略图。按照这些思路，您可以调整它以使用适当的路径和方法名称。

class User < ActiveRecord::Base

  def avatar_or_missing_path
    if self.avatar
      self.avatar.public_path #or whatever the method is to get the path to the avatar image
    else
      "/images/avatars/missing/#{self.first_name[0].upcase}.jpg"
    end
  end
end

然后在视图中你可以说

<%= image_tag user.avatar_or_missing_path %>

或其他什么。

Answer 2

based on the first character of the user's first name

一种更有效的方法是将 CSS 与 :before 伪 class 一起使用，并填充 attr function (JSFiddle):

#app/views/users/show.html.erb
<%= content_tag :div, class: "user_image", data: { name: @user.name[0] } do %>
  <%= image_tag ... if @user.avatar %>
<% end %>

#app/assets/stylesheets/application.css
.user_image {
  display: block;
  position: relative;
  width:  50px;
  height: 50px;
  margin: 1px;
  background: #f00;
}

.user_image:before {
  content: attr(data-name);
  color: #fff;
  position: absolute;
  font-size: 18px;
  left: 40%;
  top: 30%;
}

这意味着您应该从 User 头像中删除 missing 功能：

#app/models/user.rb
class User < ActiveRecord::Base
    has_attached_file :avatar, styles: { medium: "300x300", thumb: "100x100", small: "50x50", mini: "25x25>", xsmall: "15x15" },
                url: "/assets/users/:id/:style/:basename.:extension",
                path: ":rails_root/public/assets/users/:id/:style/:basename.:extension"
    validates_attachment :avatar, content_type: { content_type: ["image/jpeg", "image/jpg", "image/gif", "image/png"] }, size: { less_than: 3.megabytes }
end

插值

如果你想让 "missing" 图像使用用户名的第一个字母，你需要查看 Paperclip Interpolation:

#app/models/user.rb
class User < ActiveRecord::Base
    has_attached_file :avatar, default_url: ":style/missing/:missing_user.jpeg"
    validates_attachment :avatar, content_type: { content_type: ["image/jpeg", "image/jpg", "image/gif", "image/png"] }, size: { less_than: 3.megabytes }
end

#config/initializers/paperclip.rb
Paperclip.interpolates :missing_user do |attachment, style|
  attachment.instance.user.name[0] #-> might be attachment.instance.name[0]
end

最后，如果你想清理回形针模型，你应该查看 default_options 散列（可以在模型中覆盖）：

#config/application.rb
config.paperclip.defaults = {
  styles: { medium: "300x300", thumb: "100x100", small: "50x50", mini: "25x25>", xsmall: "15x15" },
  url: "/assets/users/:id/:style/:basename.:extension",
  path: ":rails_root/public/assets/users/:id/:style/:basename.:extension"
}

#app/models/user.rb
class User < ActiveRecord::Base
  has_attached_file :avatar
end

Answer 3

我自己的生成带有用户首字母的头像的解决方案：https://github.com/igorkasyanchuk/avatarro

  <%= image_tag Avatarro.image(current_user.full_name), size: '24x24' %>
  <%= image_tag Avatarro.image("Igor Kasyanchuk", solid: true), size: '24x24' %>
  <%= image_tag Avatarro.image("IK"), size: '32x32' %>
  <%= raw Avatarro.svg("IK") %>

在 ruby rails 上通过回形针根据用户名的第一个字符添加缺失的图像

Add missing images based on user name's first character through paper clip in ruby on rails

ruby-on-rails

paperclip