Question

我遵循了Michael Hartl的“Rails Tutorial”一书，需要在自定义位置（/成员）而不是站点的根目录上呈现“微博提要”。

我已更新SessionsController，以便在用户登录时将其重定向到新的/成员URL，但成员视图上需要两个语句，这些语句会导致错误并阻止页面加载微博提要。

# app/views/members/index.html.erb
<%= render 'shared/micropost_form' %>
<%= render 'shared/feed' %>

第一个错误是：

ArgumentError in MembersController#index
First argument in form cannot contain nil or be empty

返回raise ArgumentError, "First argument in form cannot contain nil or be empty" unless object 第二个错误（在删除第一个render语句时看到）返回undefined method 'any?' for nil:NilClass

此问题的部分原因是，要在/members处呈现“微博提要”，app/views/members/index.html.erb似乎需要访问app/controllers/microposts_controller.rb，我不确定如何处理此问题。

更新

micropost_controller.rb

# controllers/micropost_controller.rb

class MicropostsController < ApplicationController
  before_action :logged_in_user, only: [:create, :destroy]
  before_action :correct_user,   only: :destroy

  def create
    @micropost = current_user.microposts.build(micropost_params)
    if @micropost.save
      flash[:success] = "Micropost created!"
      redirect_to '/members'
    else
      @feed_items = []
      render '/members'
    end
  end

  def destroy
    @micropost.destroy
    flash[:success] = "Micropost deleted"
    redirect_to request.referrer || '/members'
  end

  private

    def micropost_params
      params.require(:micropost).permit(:content, :picture)
    end

    def correct_user
      @micropost = current_user.microposts.find_by(id: params[:id])
      redirect_to '/members' if @micropost.nil?
    end
end

_micropost_form.html.erb

# shared/_micropost_form.html.erb

<%= form_for(@micropost, html: { multipart: true }) do |f| %>
  <%= render 'shared/error_messages', object: f.object %>
  <div class="field">
    <%= f.text_area :content, placeholder: "Compose new micropost (420 chars max)..." %>
  </div>
  <%= f.submit "Post", class: "btn btn-primary" %>
  <span class="picture">
    <%= f.file_field :picture, accept: 'image/jpeg,image/gif,image/png' %>
  </span>
<% end %>

<script type="text/javascript">
  $('#micropost_picture').bind('change', function() {
    size_in_megabytes = this.files[0].size/1024/1024;
    if (size_in_megabytes > 5) {
      alert('Maximum file size is 5MB. Please choose a smaller file.');
    }
  });
</script>

_feed.html.erb

# shared/_feed.html.erb

<% if @feed_items.any? %>
  <ol class="microposts">
    <%= render @feed_items %>
  </ol>
  <%= will_paginate @feed_items %>
<% end %>

MembersController（根据@ Mandeep的建议更新）

class MembersController < ApplicationController
  def index
    @micropost = current_user.microposts.build
    @feed_items = current_user.microposts
  end
end

Answer 1

你没有在你的部分中传递参数。您需要执行以下操作：

<%= render 'shared/micropost_form', :locals => { :micropost => @micropost }  %>
<%= render 'shared/feed', :locals => { :feed_items => @feed_items }  %>

请记住，您需要在index方法中包含这两个变量：@micropost和@feed_items。

Answer 2

将此代码添加到您的控制器：

class MembersController < ApplicationController
  def index
    @micropost = current_user.microposts.build
    @feed_items = current_user.microposts
  end
end

在自定义位置/视图中从Rails教程渲染“微博输入”？

2 个答案: