Question

初学者错误我试图在文章更新时向所有当前用户发送电子邮件。

我有sendgrid和devise设置我的应用程序，并能够让邮件通过rails控制台工作。但是，出于某种原因，我在更新文章时收到了undefined method email for #<User::ActiveRecord_Relation:0x007f8685aebec0>。

ArticleNotificationMailer

    class ArticleNotificationMailer < ApplicationMailer
        default from: 'you@example.com'

      def new_article(user, article)
        @user = user
        @article = article

        mail(
          to: @user.email,
          subject: "New update to article #{article.title}"
          )
      end
    end

new_article.html.erb

    <!DOCTYPE html>
    <html>
      <head>
        <meta content="text/html; charset=UTF-8" http-equiv="Content-type" />
      </head>
      <body>
        <h1>New article on website "<%= @article.title %>"</h1>
        <p>
          <%= @article.body %>
        </p>
        <p>
          <%= link_to "View Comment on site", article_url(@article, anchor: "updates=#{@article.id}") %>
        </p>
      </body>
    </html>

ArticleController 我正在使用ArticleNotificationMailer.new_article(@user, @article).deliver

      def update
        respond_to do |format|
          if @article.update(article_params)
            ArticleNotificationMailer.new_article(@user, @article).deliver
            format.html { redirect_to @article, notice: 'Article was successfully updated.' }
            format.json { render :show, status: :ok, location: @article }
          else
            format.html { render :edit }
            format.json { render json: @article.errors, status: :unprocessable_entity }
          end
        end
      end

错误消息

NoMethodError in ArticlesController#update
undefined method `email' for #<User::ActiveRecord_Relation:0x007f8685aebec0>

mail(
  to: @user.email,
  subject: "New post to articles #{article.title}"
  )
end

Rails控制台

>> u = User.last
>> a = Article.first
>> ActionNotificationMailer.new_article(u, a).deliver_now

Answer 1

 ArticleNotificationMailer.new_article(@user, @article).deliver

似乎 @user 由控制器中的 User.where（）初始化。 User.where 会返回 User :: ActiveRecord_Relation 的实例，实际上是rails-enhanced数组。当您尝试在此阵列上调用电子邮件时会出现错误。

如果您只需要查找一条记录，只需使用 User.find 。

Answer 2

尝试传入元素的id。

class ArticleNotificationMailer < ApplicationMailer
        default from: 'you@example.com'

      def new_article(user_id, article_id)
        @user = User.where(id: user_id)
        @article = Article.where(id: article_id)

        mail(
          to: @user.email,
          subject: "New update to article #{article.title}"
          )
      end
    end


In your console 
>> u = User.last
>> a = Article.first
>> ActionNotificationMailer.new_article(u.id, a.id).deliver_now

Answer 3

我想出了如何解决这个问题。

我将以下代码添加到article.rb并添加了@ article.send_notifications！到我的更新控制器。

def send_notifications!
 user = User.all
 user.each do |user|
   ArticleNotificationMailer.new_article(user, self).deliver_now
 end
end

Rails ActionMailer错误未定义的电子邮件

3 个答案: