按类别id rails排序

Question

我创建了一个应用程序，您可以对主题进行排序并相应地下载学术文件。 我首先创建了一个用户可以查看所有类别的应用程序，并且有一个下拉框可以对所有类别进行排序并相应地显示它。

现在，我的客户只希望主题相关用户只查看他们各自的材料。其他类别不得为他们所见。

例如，如果我的用户表上有教师=“Ruby”。我必须只能查看所有Ruby文件，不能显示其他文件。请帮我将此功能集成到我的应用程序中。

这是我当前工作的index.html.erb和assignment_controller（这里我们可以根据类别进行排序，但它会显示所有文件）

class AssignmentsController < ApplicationController
  before_action :authenticate_user!
  before_action :set_assignment, only: [:show, :edit, :update, :destroy]


  def index
    if params[:category].blank?
      @assignments = Assignment.all.order("created_at DESC")
    else
      @category_id = Category.find_by(name: params[:category]).id
      @assignments = Assignment.where(:category_id => @category_id).order("created_at DESC")
    end
  end


  def show
  end

  def new
    @assignment = current_user.assignments.build
    @categories = Category.all.map{ |c| [c.name, c.id]}
  end


  def edit
    @categories = Category.all.map{ |c| [c.name, c.id]}
  end


  def create

    @assignment = current_user.assignments.build(assignment_params)
    @assignment.category_id = params[:category_id]

    respond_to do |format|
      if @assignment.save
        format.html { redirect_to @assignment, notice: 'Assignment was successfully created.' }
        format.json { render :show, status: :created, location: @assignment }
      else
        format.html { render :new }
        format.json { render json: @assignment.errors, status: :unprocessable_entity }
      end
    end
  end


  def update
    authorize @assignment
    @assignment.category_id = params[:category_id]
    respond_to do |format|
      if @assignment.update(assignment_params)
        format.html { redirect_to @assignment, notice: 'Assignment was successfully updated.' }
        format.json { render :show, status: :ok, location: @assignment }
      else
        format.html { render :edit }
        format.json { render json: @assignment.errors, status: :unprocessable_entity }
      end
    end
  end


  def destroy
    authorize @assignment
    @assignment.destroy
    respond_to do |format|
      format.html { redirect_to assignments_url, notice: 'Assignment was successfully destroyed.' }
      format.json { head :no_content }
    end
  end
rescue_from Pundit::NotAuthorizedError, with: :user_not_authorized
  private

    def user_not_authorized
      flash[:warning] = "You are not authorized to perform this action."
      redirect_to(request.referrer || root_path)
    end
    # Use callbacks to share common setup or constraints between actions.
    def set_assignment
      @assignment = Assignment.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def assignment_params
      params.require(:assignment).permit(:title, :detail, :due_date, :category_id, :attachment)
    end
end

ERB档案：

<% if !flash[:notice].blank? %>
  <div class="alert alert-info">
  <%= flash[:notice] %>
  </div>
  <% end %>
<br />
<div class="dropdown">
  <button class="btn btn-default dropdown-toggle" type="button" id="dropdownMenu1" data-toggle="dropdown" aria-haspopup="true" aria-expanded="true">
    Sort By Model Name
    <span class="caret"></span>
  </button>
  <ul class="dropdown-menu" aria-labelledby="dropdownMenu1">
    <% Category.all.each do |category| %>
          <li class="<%= 'active' if params[:category] == category.name %>">
            <%= link_to category.name, assignments_path(category: category.name), class: "link" %>
          </li>
        <% end %>
  </ul>
</div>

<h1 class="current-category"><%= params[:category] %></h1>
<% if @assignments.count == 0 %>

  <h1>There are no file uploaded for this Model</h1>
  <% else %>  
<br />
<h1>Listing Assignments</h1>

<%= current_user.faculty %>
<table class="table table-bordered table-striped">
  <thead>
    <tr>
      <th>Title</th>
      <th>Detail</th>
      <th>Due date</th>
      <th>Days Remaining</th>
      <th>Latest Updated</th>
      <th>Download Link</th>
      <th colspan="3"></th>
    </tr>
  </thead>

  <tbody>
    <% @assignments.each do |assignment| %>
      <tr>
        <td><%= assignment.title %></td>
        <td><%= assignment.detail %></td>
        <td><%= assignment.due_date %></td>
        <td> <%= (assignment.due_date.to_i - Time.now.to_i)/86400%></td>
        <td><%= distance_of_time_in_words(assignment.updated_at, Time.now)  %> ago</td>
        <td><%= link_to "Download File", assignment.attachment_url %></td>
        <td><%= link_to 'Show', assignment %></td>
        <% if policy(assignment).destroy? %>
        <td><%= link_to 'Edit', edit_assignment_path(assignment) %></td>

        <td><%= link_to 'Destroy', assignment, method: :delete, data: { confirm: 'Are you sure?' } %></td><% end %>
      </tr>
    <% end %>
  </tbody>
</table>

<br>
<% end %> 

<%= link_to 'New Assignment', new_assignment_path %>