Ruby 在 Rails - 添加评论到 post
Ruby on Rails - Adding comments to post
正在尝试学习 RoR。当前由用户向帖子添加评论。到目前为止，我有一个帖子模型、评论模型和 post_comments 模型（将两者关联起来）。所以在 'rails console' 中我可以 运行：（假设我设置 p = Post.first 和 c = Comment.first）
p.comments << c
这形成了一个关联，因此它可以在控制台中工作。我似乎无法从 UI 获得形成该协会的评论。到目前为止，我正在 "comments/new" 创建评论（不确定这是否是问题所在。是否需要在 "show view" 上为 "post" 创建评论）。
这是一些代码片段
Controllers
comments_controller.rb
class CommentsController < ApplicationController
def index
@comment = Comment.all
end
def new
@comment = Comment.new
end
def create
@comment = Comment.new(commentParams)
if @comment.save
flash[:success] = "Comment successfully added"
redirect_to comments_path(@comment)
else
render 'new'
end
end
def show
@comment = Comment.find(params[:id])
end
private
def commentParams
params.require(:comment).permit(:comment)
end
end
posts_controller
class PostsController < ApplicationController
before_action :setPost, only: [:edit, :update, :show, :destroy, :sold]
before_action :requireUser, except: [:index, :show]
before_action :requireSameUser, only: [:edit, :update, :destroy, :sold]
def index
@posts = Post.paginate(page: params[:page], per_page: 20)
end
def new
@post = Post.new
end
def create
@post = Post.new(postParams)
@post.user = currentUser
if @post.save
flash[:success] = "Post successfully added."
redirect_to post_path(@post)
else
render 'new'
end
end
def update
if @post.update(postParams)
flash[:success] = "Post successfully updated."
redirect_to post_path(@post)
else
render 'edit'
end
end
def show
end
def edit
end
def sold
@post.toggle(:sold)
@post.save
redirect_to post_path(@post)
end
def destroy
@post.destroy
flash[:danger] = "Item successfully deleted."
redirect_to posts_path
end
private
def postParams
params.require(:post).permit(:title, :price, :description, category_ids:[])
end
def setPost
@post = Post.find(params[:id])
end
def requireSameUser
if currentUser != @post.user and !currentUser.admin
flash[:danger] = "You can only edit or delete your own items"
redirect_to root_path
end
end
end
Models
comment.rb
class Comment < ActiveRecord::Base
belongs_to :post_comments
belongs_to :user
belongs_to :post
end
post_comment.rb
class PostComment < ActiveRecord::Base
belongs_to :post
belongs_to :comment
end
post.rb
class Post < ActiveRecord::Base
belongs_to :user
has_many :post_categories
has_many :categories, through: :post_categories
has_many :post_comments
has_many :comments, through: :post_comments
validates :title, presence: true,
length: { minimum: 4, maximum: 20 }
validates :description, presence: true,
length: { maximum: 1000 }
validates :user_id, presence: true
结束
Views
posts/show.html.erb
<p>Comments: <%= render @post.comments %></p>
这呈现了下面的部分
comments/_comment.html.erb
<%= link_to comment.name, comment_path(comment) %>
终于是新的评论页面了
comments/new.html.erb
<h1>New Comment</h1>
<%= render 'shared/errors', obj: @comment %>
<div class="row">
<div class="col-xs-12">
<%= form_for(@comment, :html => {class: "form-horizontal", role: "form"}) do |f| %>
<div class="form-group">
<div class="control-label col-sm-2">
<%= f.label :comment %>
</div>
<div class="col-sm-8">
<%= f.text_area :comment, rows: 3, class: "form-control", placeholder: "Please enter a comment", autofocus: true %>
</div>
</div>
<div class="form-group">
<div class="center col-sm-offset-1 col-sm-10">
<%= f.submit class: "btn btn-primary btn-lg" %>
</div>
</div>
<% end %>
如有任何帮助，我们将不胜感激。
更新
Log
Started GET "/posts/2" for ::1 at 2016-01-15 12:39:55 +0000
Processing by PostsController#show as HTML
Parameters: {"id"=>"2"}
[1m[36mPost Load (0.1ms)[0m [1mSELECT "posts".* FROM "posts" WHERE "posts"."id" = ? LIMIT 1[0m [["id", 2]]
[1m[35mUser Load (0.1ms)[0m SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1 [["id", 1]]
[1m[36m (0.1ms)[0m [1mSELECT COUNT(*) FROM "posts" WHERE "posts"."user_id" = ?[0m [["user_id", 1]]
[1m[35mCategory Exists (0.1ms)[0m SELECT 1 AS one FROM "categories" INNER JOIN "post_categories" ON "categories"."id" = "post_categories"."category_id" WHERE "post_categories"."post_id" = ? LIMIT 1 [["post_id", 2]]
[1m[36mCategory Load (0.0ms)[0m [1mSELECT "categories".* FROM "categories" INNER JOIN "post_categories" ON "categories"."id" = "post_categories"."category_id" WHERE "post_categories"."post_id" = ?[0m [["post_id", 2]]
Rendered categories/_category.html.erb (0.2ms)
[1m[35mComment Load (0.1ms)[0m SELECT "comments".* FROM "comments" WHERE "comments"."post_id" = ? [["post_id", 2]]
Rendered comments/_comment.html.erb (0.1ms)
Rendered posts/show.html.erb within layouts/application (6.5ms)
[1m[36mCategory Load (0.1ms)[0m [1mSELECT "categories".* FROM "categories"[0m
Rendered layouts/_navigation.html.erb (0.9ms)
Rendered layouts/_messages.html.erb (0.1ms)
Rendered layouts/_footer.html.erb (0.1ms)
Completed 200 OK in 52ms (Views: 50.3ms | ActiveRecord: 0.5ms)
由于评论只能属于单个 post，因此您不需要关联 table (post_comments)。你只需要一个简单的 one-to-many 关系。
您的 post 评论将是：
class Post < ActiveRecord::Base
has_many :comments
...
end
评论会是这样的：
class Comment < ActiveRecord::Base
belongs_to :post
...
end
只需确保 comments table 中有必要的 post_id 列（您可以检查 db/schema.rb 文件）。如果缺少，您可以使用以下迁移来添加它：
class AddPostIdToComments < ActiveRecord::Migration
def change
add_column :comments, :post_id, :integer
add_index :comments, :post_id
end
end
您还需要确保在某处保留对 post 的引用，每当用户尝试对 post 创建评论时。您可以将其添加到 comments/new.html.erb 模板的隐藏字段中。在通过 URL.
传递后，您可以在 PostsController 的 new 操作中设置隐藏字段
因此，在您的 posts/show.html.erb 模板中，您将拥有：
<%= link_to "Add Comment", new_comment_path(post_id: @post.id) %>
在您的 new 操作中，在 PostsController:
def new
@comment = Comment.new(post_id: params[:post_id])
end
最后，您表单中的隐藏字段将是：
<%= f.hidden_field :post_id %>
最后，将 post_id 参数添加到 CommentsController 中允许的参数列表中。
而不是
在您的新操作中，在 PostsController 中：
def new
@comment = Comment.new(post_id: params[:post_id])
end
您可以在表单视图中使用它
<%= form.hidden_field :post_id, value: "#{params[:post_id]}" %>
正在尝试学习 RoR。当前由用户向帖子添加评论。到目前为止，我有一个帖子模型、评论模型和 post_comments 模型（将两者关联起来）。所以在 'rails console' 中我可以 运行：（假设我设置 p = Post.first 和 c = Comment.first）
p.comments << c
这形成了一个关联，因此它可以在控制台中工作。我似乎无法从 UI 获得形成该协会的评论。到目前为止，我正在 "comments/new" 创建评论（不确定这是否是问题所在。是否需要在 "show view" 上为 "post" 创建评论）。
这是一些代码片段
Controllers comments_controller.rb
class CommentsController < ApplicationController
def index
@comment = Comment.all
end
def new
@comment = Comment.new
end
def create
@comment = Comment.new(commentParams)
if @comment.save
flash[:success] = "Comment successfully added"
redirect_to comments_path(@comment)
else
render 'new'
end
end
def show
@comment = Comment.find(params[:id])
end
private
def commentParams
params.require(:comment).permit(:comment)
end
end
posts_controller
class PostsController < ApplicationController
before_action :setPost, only: [:edit, :update, :show, :destroy, :sold]
before_action :requireUser, except: [:index, :show]
before_action :requireSameUser, only: [:edit, :update, :destroy, :sold]
def index
@posts = Post.paginate(page: params[:page], per_page: 20)
end
def new
@post = Post.new
end
def create
@post = Post.new(postParams)
@post.user = currentUser
if @post.save
flash[:success] = "Post successfully added."
redirect_to post_path(@post)
else
render 'new'
end
end
def update
if @post.update(postParams)
flash[:success] = "Post successfully updated."
redirect_to post_path(@post)
else
render 'edit'
end
end
def show
end
def edit
end
def sold
@post.toggle(:sold)
@post.save
redirect_to post_path(@post)
end
def destroy
@post.destroy
flash[:danger] = "Item successfully deleted."
redirect_to posts_path
end
private
def postParams
params.require(:post).permit(:title, :price, :description, category_ids:[])
end
def setPost
@post = Post.find(params[:id])
end
def requireSameUser
if currentUser != @post.user and !currentUser.admin
flash[:danger] = "You can only edit or delete your own items"
redirect_to root_path
end
end
end
Models comment.rb
class Comment < ActiveRecord::Base
belongs_to :post_comments
belongs_to :user
belongs_to :post
end
post_comment.rb
class PostComment < ActiveRecord::Base
belongs_to :post
belongs_to :comment
end
post.rb
class Post < ActiveRecord::Base
belongs_to :user
has_many :post_categories
has_many :categories, through: :post_categories
has_many :post_comments
has_many :comments, through: :post_comments
validates :title, presence: true,
length: { minimum: 4, maximum: 20 }
validates :description, presence: true,
length: { maximum: 1000 }
validates :user_id, presence: true
结束
Views posts/show.html.erb
<p>Comments: <%= render @post.comments %></p>
这呈现了下面的部分
comments/_comment.html.erb <%= link_to comment.name, comment_path(comment) %>
终于是新的评论页面了
comments/new.html.erb
<h1>New Comment</h1>
<%= render 'shared/errors', obj: @comment %>
<div class="row">
<div class="col-xs-12">
<%= form_for(@comment, :html => {class: "form-horizontal", role: "form"}) do |f| %>
<div class="form-group">
<div class="control-label col-sm-2">
<%= f.label :comment %>
</div>
<div class="col-sm-8">
<%= f.text_area :comment, rows: 3, class: "form-control", placeholder: "Please enter a comment", autofocus: true %>
</div>
</div>
<div class="form-group">
<div class="center col-sm-offset-1 col-sm-10">
<%= f.submit class: "btn btn-primary btn-lg" %>
</div>
</div>
<% end %>
如有任何帮助，我们将不胜感激。
更新
Log
Started GET "/posts/2" for ::1 at 2016-01-15 12:39:55 +0000
Processing by PostsController#show as HTML
Parameters: {"id"=>"2"}
[1m[36mPost Load (0.1ms)[0m [1mSELECT "posts".* FROM "posts" WHERE "posts"."id" = ? LIMIT 1[0m [["id", 2]]
[1m[35mUser Load (0.1ms)[0m SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1 [["id", 1]]
[1m[36m (0.1ms)[0m [1mSELECT COUNT(*) FROM "posts" WHERE "posts"."user_id" = ?[0m [["user_id", 1]]
[1m[35mCategory Exists (0.1ms)[0m SELECT 1 AS one FROM "categories" INNER JOIN "post_categories" ON "categories"."id" = "post_categories"."category_id" WHERE "post_categories"."post_id" = ? LIMIT 1 [["post_id", 2]]
[1m[36mCategory Load (0.0ms)[0m [1mSELECT "categories".* FROM "categories" INNER JOIN "post_categories" ON "categories"."id" = "post_categories"."category_id" WHERE "post_categories"."post_id" = ?[0m [["post_id", 2]]
Rendered categories/_category.html.erb (0.2ms)
[1m[35mComment Load (0.1ms)[0m SELECT "comments".* FROM "comments" WHERE "comments"."post_id" = ? [["post_id", 2]]
Rendered comments/_comment.html.erb (0.1ms)
Rendered posts/show.html.erb within layouts/application (6.5ms)
[1m[36mCategory Load (0.1ms)[0m [1mSELECT "categories".* FROM "categories"[0m
Rendered layouts/_navigation.html.erb (0.9ms)
Rendered layouts/_messages.html.erb (0.1ms)
Rendered layouts/_footer.html.erb (0.1ms)
Completed 200 OK in 52ms (Views: 50.3ms | ActiveRecord: 0.5ms)
由于评论只能属于单个 post，因此您不需要关联 table (post_comments)。你只需要一个简单的 one-to-many 关系。
您的 post 评论将是：
class Post < ActiveRecord::Base
has_many :comments
...
end
评论会是这样的：
class Comment < ActiveRecord::Base
belongs_to :post
...
end
只需确保 comments table 中有必要的 post_id 列（您可以检查 db/schema.rb 文件）。如果缺少，您可以使用以下迁移来添加它：
class AddPostIdToComments < ActiveRecord::Migration
def change
add_column :comments, :post_id, :integer
add_index :comments, :post_id
end
end
您还需要确保在某处保留对 post 的引用，每当用户尝试对 post 创建评论时。您可以将其添加到 comments/new.html.erb 模板的隐藏字段中。在通过 URL.
new 操作中设置隐藏字段
因此，在您的 posts/show.html.erb 模板中，您将拥有：
<%= link_to "Add Comment", new_comment_path(post_id: @post.id) %>
在您的 new 操作中，在 PostsController:
def new
@comment = Comment.new(post_id: params[:post_id])
end
最后，您表单中的隐藏字段将是：
<%= f.hidden_field :post_id %>
最后，将 post_id 参数添加到 CommentsController 中允许的参数列表中。
而不是
在您的新操作中，在 PostsController 中：
def new
@comment = Comment.new(post_id: params[:post_id])
end
您可以在表单视图中使用它
<%= form.hidden_field :post_id, value: "#{params[:post_id]}" %>