如何在Feed中添加多态注释? [英] How to Add Polymorphic Comments to Feed?
问题描述
我试图允许用户直接在其活动供稿上添加和查看评论，而不是必须转到显示页面，这是我通过此railscast剧集所做的事情:
I'm trying to allow users to add and see comments directly on their activities feed, instead of having to go to a show page, which is what I got up to with this railscast episode: http://railscasts.com/episodes/154-polymorphic-association-revised.
我从头开始创建了活动供稿.
I created the activities feed from scratch.
下面是我所做的尝试之一.我将逻辑直接添加到索引操作中:
Below is one of the attempt's I made. I added the logic directly into the index action:
class ActivitiesController < ApplicationController
def index
@activities = Activity.order("created_at desc").where(current_user.following_ids)
@activity = Activity.find(params[:id])
@commentable = @activity
@comments = @commentable.comments
@comment = Comment.new
end
end
告诉我:ActiveRecord::RecordNotFound in ActivitiesController#index
Couldn't find Activity with 'id'=
which tells me: ActiveRecord::RecordNotFound in ActivitiesController#index
Couldn't find Activity with 'id'=
我试图直接在活动索引中呈现评论的部分内容:
I attempted to render the comments partials directly in the activities index:
<% @activities.each do |activity| %>
<%= link_to activity.user.name, activity.user %>
<%= render "activities/#{activity.trackable_type.underscore}/#{activity.action}", activity: activity %>
<%= render "comments/comments" %>
<%= render "comments/form" %>
<% end %>
评论/评论& 评论/表格
<% @comments.each do |comment| %>
<%= User.find(comment.user_id).name %>
<%= simple_format comment.content %>
<% end %>
<%= form_for [@commentable, @comment] do |f| %>
<%= f.text_area :content, rows: 4, class: 'form-control', placeholder: 'Enter Comment' %>
<%= button_tag(type: 'submit', class: "btn") do %>
<span class="glyphicon glyphicon-plus"></span> Comment
<% end %>
<% end %>
activity.rb
class Activity < ActiveRecord::Base
belongs_to :user
has_many :comments, as: :commentable
belongs_to :trackable, polymorphic: true
end
感谢您的专业知识！
comments_controller.rb
class CommentsController < ApplicationController
before_action :load_commentable
before_action :set_comment, only: [:show, :edit, :update, :destroy, :like]
before_action :logged_in_user, only: [:create, :destroy]
def index
@comments = @commentable.comments
end
def new
@comment = @commentable.comments.new
end
def create
@comment = @commentable.comments.new(comment_params)
if @comment.save
redirect_to @commentable, notice: "comment created."
else
render :new
end
end
def edit
@comment = current_user.comments.find(params[:id])
end
def update
@comment = current_user.comments.find(params[:id])
if @comment.update_attributes(comment_params)
redirect_to @commentable, notice: "Comment was updated."
else
render :edit
end
end
def destroy
@comment = current_user.comments.find(params[:id])
@comment.destroy
redirect_to @commentable, notice: "comment destroyed."
end
def like
@comment = Comment.find(params[:id])
@comment_like = current_user.comment_likes.build(comment: @comment)
if @comment_like.save
@comment.increment!(:likes)
flash[:success] = 'Thanks for liking!'
else
flash[:error] = 'Two many likes'
end
redirect_to(:back)
end
private
def set_comment
@comment = Comment.find(params[:id])
end
def load_commentable
resource, id = request.path.split('/')[1, 2]
@commentable = resource.singularize.classify.constantize.find(id)
end
def comment_params
params[:comment][:user_id] = current_user.id
params.require(:comment).permit(:content, :commentable, :user_id, :like)
end
end
模式
create_table "activities", force: true do |t|
t.integer "user_id"
t.string "action"
t.integer "trackable_id"
t.string "trackable_type"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
add_index "activities", ["trackable_id"], name: "index_activities_on_trackable_id"
add_index "activities", ["user_id"], name: "index_activities_on_user_id"
activities GET /activities(.:format) activities#index
POST /activities(.:format) activities#create
new_activity GET /activities/new(.:format) activities#new
edit_activity GET /activities/:id/edit(.:format) activities#edit
activity GET /activities/:id(.:format) activities#show
PATCH /activities/:id(.:format) activities#update
PUT /activities/:id(.:format) activities#update
DELETE /activities/:id(.:format) activities#destroy
推荐答案
您可以执行以下操作:
# activites/index.html.erb
<% @activities.each do |activity| %>
# etc.
<%= render "comments/comments", comments: activity.comments %>
<%= render "comments/form" %>
<% end %>
# comments/_comments.html.erb
<% comments.each do |comment| %>
# your code to display each comment
<% end %>
您可以看到我向render方法传递了一个参数:
You can see that I passed an argument to the render method:
render "comments/comments", comments: activity.comments
它将给_comments部分局部变量comments，它等于activity.comments.
It will give to the _comments partial the local variable comments which will be equal to activity.comments.
您甚至可以使用form部分执行几乎相同的操作:
You can even do the almost-same-thing with the form partial:
# activites/index.html.erb
<%= render "comments/form", new_comment: Comment.new(commentable_id: activity.id, commentable_type: activity.class.model_name) %>
# comments/_form.html.erb
<% form_for new_comment do |f| %>
此外，Ruby on Rails中的一个好习惯是不要创建多个实例变量@like_this_one.将其保持在最低限度，因为它可能会造成混淆.我还要补充一点，您的变量命名也很重要.
Also, a good practice in Ruby on Rails is to not create several instance variables @like_this_one. Keep it to the minimum because it can be confusing. I will add that your variable naming is important too.
以下内容:
@activity = Activity.find(params[:id])
@commentable = @activity
@comments = @commentable.comments
可以重构为:
@activity = Activity.find(params[:id])
然后在您的视图中，您可以通过以下方式访问评论:
And then in your views you could access to the comments by doing:
@activity.comments
这篇关于如何在Feed中添加多态注释?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
