Rails ActionMailer 错误未定义电子邮件

Question

初学者 rails 错误 我正在尝试在文章更新时向所有当前用户发送电子邮件。

我已经使用我的应用程序设置了 sendgrid 和设计，并且能够让邮件程序通过 rails 控制台工作。但是，出于某种原因，我在更新文章时收到 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>

文章控制器 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

错误信息

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 在您的控制器中由 User.where() 初始化。 User.where returns User::ActiveRecord_Relation 的实例实际上是 rails - 增强数组。当您尝试在此数组上调用 email 时出现错误。

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

我想出了解决办法。

我在article.rb中添加了下面的代码，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 错误未定义电子邮件

Rails ActionMailer error undefined email

ruby-on-rails

actionmailer

sendgrid