javascript - 允许用户通过 ajax 志愿执行任务

Question

我的应用程序设置为用户拥有任务并且其他用户可以自愿完成这些任务。我的模型设置如下:

用户

class User < ActiveRecord::Base
  has_many :participations, foreign_key: :participant_id
  has_many :owned_tasks, class_name: "Task", foreign_key: :owner_id
end

参与(加入表)

class Participation < ActiveRecord::Base
  enum status: [:interested, :selected]

  belongs_to :task
  belongs_to :participant, class_name: "User"
end

任务

class Task < ActiveRecord::Base
  enum status: [:open, :in_progress, :complete]

  has_many :participations
  has_many :participants, through: :participations, source: :participant
  # Dynamically generates relations such as 'selected_participants'
  Participation.statuses.keys.each do |status|
    has_many "#{status}_participants".to_sym,
    -> { where(participations: { status: status.to_sym }) },
    through: :participations,
    source: :participant
  end

  belongs_to :owner, class_name: "User"
end

我想要做的只是允许用户单击一个按钮来自愿在特定任务的显示 View 中执行任务。

我可以在 Rails 控制台中轻松完成此操作:

user = User.first
task = Task.first
user.owned_tasks << task

user_2 = User.find(2)
task.participants << user_2

我陷入困境的是试图弄清楚如何设置必要的 Controller 代码以使其正常工作。我也不确定如何/在哪里创建检查用户是否已经参与任务 is_participating? 的条件。它是进入加入模式Participation 还是Task 表？

我想我对 View 应该是什么样子有一个模糊的想法:

任务 - 显示 View

<% unless current_user == @task.owner %>
  <div class="volunteer-form">
    <% if current_user.is_participating? %>
        <%= render 'cancel' %>
    <% else %>
        <%= render 'volunteer' %>
    <% end %>
 </div>
<% end %>

_volunteer.html.erb:

 <%= form_for(current_user.participations.build(participant_id: current_user), remote: true) do |f| %>
    <div><%= f.hidden_field :participant_id %></div>
    <%= f.submit "Volunteer" %>
 <% end %>

_cancel.html.erb:

<%= form_for(current_user.participations.find_by(participant_id: current_user), html: { method: :delete }, remote: true) do |f| %>
   <%= f.submit "Cancel" %>
<% end %>

JS

// create.js.erb
$(".volunteer-form").html("<%= escape_javascript(render('tasks/volunteer')) %>");

// destroy.js.erb
$(".volunteer-form").html("<%= escape_javascript(render('tasks/cancel')) %>");

Answer 1

从您看来，is_participating? 属于 User 模型，它可能应该是这样的:

def is_participating?(task_id)
  participations.where(task_id: task_id).exists?
end

至于 Controller 代码，您可能需要以下内容:

class ParticipationsController
  # Note I assume you have access to current_user here

  def create        
    participation = current_user.participations.create(participation_params)
    respond_to do |format|
      format.js
    end
  end

  def destroy
    participation = current_user.participations.find(params[:id])
    participation.destroy

    respond_to do |format|
      format.js
    end
  end 


  protected 

  def participation_params
    params.require(:participation).permit :task_id
  end
end

在_volunteer.html.erb上(请注意，您现在必须将任务传递到部分):

<%= form_for(current_user.participations.build, remote: true) do |f| %>
    <%= f.hidden_field :task_id, value: task.id %>
    <%= f.submit "Volunteer" %>
<% end %>