Rails 6 ActionText 获取第一张图片

Question

我有 Post 模型：

class Post < ApplicationRecord
  belongs_to :user
  has_rich_text :content
end

在Post#index 我想显示一个带有标题、图像和描述的帖子。对于图像和描述，我如何从 ActionText 中获取它们？

我认为获取第一个图像〜获取第一个活动存储 blob（属于帖子），其 content_type 是图像。

irb(main):017:0> Post.last.content
  Post Load (22.6ms)  SELECT `posts`.* FROM `posts` ORDER BY `posts`.`id` DESC LIMIT 1
  ActionText::RichText Load (3.2ms)  SELECT `action_text_rich_texts`.* FROM `action_text_rich_texts` WHERE `action_text_rich_texts`.`record_id` = 12 AND `action_text_rich_texts`.`record_type` = 'Post' AND `action_text_rich_texts`.`name` = 'content' LIMIT 1
Traceback (most recent call last):
        1: from (irb):17
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 4.0ms | Allocations: 54)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.2ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.2ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.6ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.8ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.2ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.3ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.2ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/content/_layout.html.erb (Duration: 445.6ms | Allocations: 54464)
NoMethodError (undefined method `first' for #<ActionText::RichText:0x00007fb0a9e33620>)
irb(main):018:0> Post.last.content.body
  Post Load (1.6ms)  SELECT `posts`.* FROM `posts` ORDER BY `posts`.`id` DESC LIMIT 1
  ActionText::RichText Load (3.4ms)  SELECT `action_text_rich_texts`.* FROM `action_text_rich_texts` WHERE `action_text_rich_texts`.`record_id` = 12 AND `action_text_rich_texts`.`record_type` = 'Post' AND `action_text_rich_texts`.`name` = 'content' LIMIT 1
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 54)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.3ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.2ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.2ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.2ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.7ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/attachables/_remote_image.html.erb (Duration: 0.1ms | Allocations: 52)
  Rendered /Users/stronglong/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.rc2/app/views/action_text/content/_layout.html.erb (Duration: 115.7ms | Allocations: 53442)
=> #<ActionText::Content "<div class=\"trix-conte...">

参考：关于描述，我看到了这个question

Answer 1

你可以调用content.to_plain_text获取文本，调用content.embeds获取所有附件（玩关联获取第一张图片，因为它可以嵌入其他东西）

https://github.com/rails/rails/blob/master/actiontext/app/models/action_text/rich_text.rb

Answer 2

ActionText 模型提供了关联embeds，因此您可以使用方便的方法image? 调用find

Post.last
    .with_rich_text_text_and_embeds # to avoid N+1 queries
    .content
    .embeds
    .find{|embeds| embeds.image?} # to make sure embed is an image

Answer 3

感谢罗兰的回答，应该采纳了。

为避免 N+1 查询，请添加 with_rich_text_[ATTRIBUTE]_and_embeds。 https://edgeguides.rubyonrails.org/action_text_overview.html#avoid-n-1-queries

我的模型中的内容在 text 属性中。

posts_controller.rb

@post = Post.with_rich_text_text_and_embeds.find(params[:id])

show.html.erb

<% if !post.text.embeds.empty? %>
    <%= image_tag post.text.embeds.find{|embeds| embeds.image?}.variant(resize_to_limit: [200, 200]) %>
<% end %>

将欣赏任何更有效的解决方案。