使用button_to将数据发送到控制器

Question

这是按钮：

<%= button_to "I want to understand this.", articles_want_to_understand_path, :id => @article.id, method: :post %>

这是控制器代码：

def want_to_understand
  @article.user_who_wants_to_understand << current_user
  redirect_to action: :show
end

private

def set_article
  @article = Article.find(params[:id])
end

这是错误：

undefined method `user_who_wants_to_understand' for nil:NilClass

Answer 1

控制器中的

： -

before_action :set_article, only: [:want_to_understand]
def want_to_understand
  @article.user_who_wants_to_understand << current_user
  redirect_to action: :show
end

private

def set_article
  @article = Article.find(params[:id])
end

并在您的视图页面中： -

<%= button_to "I want to understand this.", articles_want_to_understand_path(id: @article.id) %>

附注：使用按钮转换为html表单，默认情况下表单是邮政类型，因此您不需要为邮政类型的路线指定方法类型帖子。