这是关于Rails 4: new instance is created and saved to database but not displayed in view的后续问题。
在我们的Rails 4应用程序中，有四种模式：
class User < ActiveRecord::Base
has_many :administrations, dependent: :destroy
has_many :calendars, through: :administrations
end
class Administration < ActiveRecord::Base
belongs_to :user
belongs_to :calendar
end
class Calendar < ActiveRecord::Base
has_many :administrations, dependent: :destroy
has_many :users, through: :administrations
end
class Post < ActiveRecord::Base
belongs_to :calendar
end
以下是相应的迁移：
class CreateUsers < ActiveRecord::Migration
def change
create_table :users do |t|
t.string :first_name
t.string :last_name
t.string :email
t.integer :total_calendar_count
t.integer :owned_calendar_count
t.timestamps null: false
end
end
end
class CreateAdministrations < ActiveRecord::Migration
def change
create_table :administrations do |t|
t.references :user, index: true, foreign_key: true
t.references :calendar, index: true, foreign_key: true
t.string :role
t.timestamps null: false
end
end
end
class CreateCalendars < ActiveRecord::Migration
def change
create_table :calendars do |t|
t.string :name
t.timestamps null: false
end
end
end
class CreatePosts < ActiveRecord::Migration
def change
create_table :posts do |t|
t.references :calendar, index: true, foreign_key: true
t.date :date
t.time :time
t.string :focus
t.string :format
t.string :blog_title
t.text :long_copy
t.text :short_copy
t.string :link
t.string :hashtag
t.string :media
t.float :promotion
t.string :target
t.integer :approval
t.text :comment
t.timestamps null: false
end
end
end
我们有以下表格来创建帖子：
<h2>Create a new post</h2>
<%= form_for(@post) do |f| %>
<%= render 'shared/error_messages', object: f.object %>
<tr>
<%= f.hidden_field :calendar_id, value: @calendar.id %>
<td class="field"><%= f.date_field :date, placeholder: "When do you want to publish this post?" %></td>
<td class="field"><%= f.time_field :time, placeholder: "What time do you want to publish this post?" %></td>
<td class="field"><%= f.text_field :focus, placeholder: "What is this post about?" %></td>
<td class="field"><%= f.text_field :format, placeholder: "What type of post is this?" %></td>
<td class="field"><%= f.text_field :blog_title, placeholder: "If this post is about a blog post, what is the title of the blog post?" %></td>
<td class="field"><%= f.text_area :long_copy, placeholder: "What is the copy of the post?" %></td>
<td class="field"><%= f.text_area :short_copy, placeholder: "What is the short copy of the post (to be used on Twitter for instance)?" %></td>
<td class="field"><%= f.url_field :link, placeholder: "Which link to you want to embed in this post?" %></td>
<td class="field"><%= f.text_field :hashtag, placeholder: "Which hashtag(s) do you want to you in this post?" %></td>
<td class="field"><%= f.text_field :media, placeholder: "Which media file (image, video) do you want to include in this post?" %></td>
<td class="field"><%= f.number_field :promotion, placeholder: "What advertising budget should be allocated to this post?" %></td>
<td class="field"><%= f.text_field :target, placeholder: "Who do you want to target with this post?" %></td>
<td class="field"><%= f.select(:approval, %w['Approved' 'Needs edits' 'To be deleted'], {prompt: 'How does this post look?'}) %></td>
<td class="field"><%= f.text_area :comment, placeholder: "Any comment?" %></td>
<td><%= f.submit "Create", class: "btn btn-primary" %></td>
</tr>
<% end %>
此表单已嵌入Calendars#Show视图中，因此只要创建帖子，它就会显示在相应的日历中。
这是我们的PostsController：
class PostsController < ApplicationController
def create
@post = Post.create(post_params)
if @post.save
redirect_to root_url
else
render root_url
end
end
end
目前，每当我们提交表单时，都不会发生任何事情：
编辑：这是服务器日志：
Started GET "/calendars/1" for ::1 at 2015-07-07 22:21:07 -0700
Processing by CalendarsController#show as HTML
Parameters: {"id"=>"1"}
Calendar Load (0.1ms) SELECT "calendars".* FROM "calendars" WHERE "calendars"."id" = ? LIMIT 1 [["id", 1]]
Post Exists (0.1ms) SELECT 1 AS one FROM "posts" WHERE "posts"."calendar_id" = ? LIMIT 1 [["calendar_id", 1]]
Post Load (0.1ms) SELECT "posts".* FROM "posts" WHERE "posts"."calendar_id" = ? [["calendar_id", 1]]
Rendered posts/_post.html.erb (0.7ms)
Rendered shared/_error_messages.html.erb (0.0ms)
Rendered shared/_post_form.html.erb (5.1ms)
Rendered calendars/show.html.erb within layouts/application (13.7ms)
Rendered layouts/_shim.html.erb (0.1ms)
User Load (0.1ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1 [["id", 1]]
Rendered layouts/_header.html.erb (0.9ms)
Rendered layouts/_footer.html.erb (0.4ms)
Completed 200 OK in 145ms (Views: 144.0ms | ActiveRecord: 0.4ms)
编辑2 ：这是新的服务器日志，在实现了@ miler350在他的回答中推荐的内容之后：
Started POST "/posts" for ::1 at 2015-07-08 09:09:58 -0700
Processing by PostsController#create as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"+LS+B2/KiUq09cypZSQnzwj5xHbNnkYR6EC5hfjNCwc3/NfFkbWi3FJe0Zw3Mumsdnubnip5piQHXZ00eV1W2A==", "post"=>{"calendar_id"=>"", "date"=>"2015-08-20", "time"=>"12:04", "focus"=>"Test", "format"=>"Test", "blog_title"=>"Test", "long_copy"=>"Test", "short_copy"=>"Test", "link"=>"http://www.google.com", "hashtag"=>"Test", "media"=>"Test", "promotion"=>"50", "target"=>"Test", "approval"=>"'Approved'", "comment"=>"Test"}, "commit"=>"Create"}
Unpermitted parameter: calendar_id
(0.1ms) begin transaction
SQL (0.7ms) INSERT INTO "posts" ("date", "time", "focus", "format", "blog_title", "long_copy", "short_copy", "link", "hashtag", "media", "promotion", "target", "approval", "comment", "created_at", "updated_at") VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?) [["date", "2015-08-20"], ["time", "2000-01-01 12:04:00.000000"], ["focus", "Test"], ["format", "Test"], ["blog_title", "Test"], ["long_copy", "Test"], ["short_copy", "Test"], ["link", "http://www.google.com"], ["hashtag", "Test"], ["media", "Test"], ["promotion", 50.0], ["target", "Test"], ["approval", 0], ["comment", "Test"], ["created_at", "2015-07-08 16:09:58.605712"], ["updated_at", "2015-07-08 16:09:58.605712"]]
(0.6ms) commit transaction
(0.0ms) begin transaction
(0.0ms) commit transaction
Redirected to http://localhost:3000/
Completed 302 Found in 9ms (ActiveRecord: 1.5ms)
Started GET "/" for ::1 at 2015-07-08 09:09:58 -0700
Processing by StaticPagesController#home as HTML
User Load (0.1ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1 [["id", 1]]
Rendered static_pages/home.html.erb within layouts/static_pages (1.8ms)
Rendered layouts/_shim.html.erb (0.0ms)
Rendered layouts/_static_header.html.erb (1.0ms)
Rendered layouts/_footer.html.erb (0.3ms)
Completed 200 OK in 148ms (Views: 147.5ms | ActiveRecord: 0.1ms)
Started GET "/users/1" for ::1 at 2015-07-08 09:10:02 -0700
Processing by UsersController#show as HTML
Parameters: {"id"=>"1"}
User Load (0.1ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1 [["id", 1]]
User Load (0.1ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1 [["id", 1]]
Rendered shared/_error_messages.html.erb (0.7ms)
Rendered shared/_calendar_form.html.erb (5.0ms)
Administration Exists (0.5ms) SELECT 1 AS one FROM "administrations" WHERE "administrations"."user_id" = ? LIMIT 1 [["user_id", 1]]
Administration Load (0.5ms) SELECT "administrations".* FROM "administrations" WHERE "administrations"."user_id" = ? [["user_id", 1]]
Calendar Load (0.1ms) SELECT "calendars".* FROM "calendars" WHERE "calendars"."id" = ? LIMIT 1 [["id", 1]]
Calendar Load (0.1ms) SELECT "calendars".* FROM "calendars" WHERE "calendars"."id" = ? LIMIT 1 [["id", 2]]
Calendar Load (0.1ms) SELECT "calendars".* FROM "calendars" WHERE "calendars"."id" = ? LIMIT 1 [["id", 3]]
Calendar Load (0.1ms) SELECT "calendars".* FROM "calendars" WHERE "calendars"."id" = ? LIMIT 1 [["id", 4]]
Calendar Load (0.1ms) SELECT "calendars".* FROM "calendars" WHERE "calendars"."id" = ? LIMIT 1 [["id", 5]]
Rendered administrations/_administration.html.erb (4.1ms)
Rendered users/show.html.erb within layouts/application (32.1ms)
Rendered layouts/_shim.html.erb (0.3ms)
Rendered layouts/_header.html.erb (0.9ms)
Rendered layouts/_footer.html.erb (0.7ms)
Completed 200 OK in 150ms (Views: 135.3ms | ActiveRecord: 1.8ms)
Started GET "/calendars/1" for ::1 at 2015-07-08 09:10:04 -0700
Processing by CalendarsController#show as HTML
Parameters: {"id"=>"1"}
Calendar Load (0.1ms) SELECT "calendars".* FROM "calendars" WHERE "calendars"."id" = ? LIMIT 1 [["id", 1]]
Post Exists (0.1ms) SELECT 1 AS one FROM "posts" WHERE "posts"."calendar_id" = ? LIMIT 1 [["calendar_id", 1]]
Post Load (0.1ms) SELECT "posts".* FROM "posts" WHERE "posts"."calendar_id" = ? [["calendar_id", 1]]
Rendered posts/_post.html.erb (1.1ms)
Rendered shared/_error_messages.html.erb (0.0ms)
Rendered shared/_post_form.html.erb (5.3ms)
Rendered calendars/show.html.erb within layouts/application (13.9ms)
Rendered layouts/_shim.html.erb (0.1ms)
User Load (0.1ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1 [["id", 1]]
Rendered layouts/_header.html.erb (0.8ms)
Rendered layouts/_footer.html.erb (0.3ms)
Completed 200 OK in 113ms (Views: 111.2ms | ActiveRecord: 0.4ms)
编辑3 ：当我将:calendar_id添加到PostsControllers中允许的post_params时，这是服务器日志：
Started GET "/calendars/1" for ::1 at 2015-07-08 11:07:39 -0700
Processing by CalendarsController#show as HTML
Parameters: {"id"=>"1"}
Calendar Load (0.1ms) SELECT "calendars".* FROM "calendars" WHERE "calendars"."id" = ? LIMIT 1 [["id", 1]]
Post Exists (0.2ms) SELECT 1 AS one FROM "posts" WHERE "posts"."calendar_id" = ? LIMIT 1 [["calendar_id", 1]]
Post Load (0.2ms) SELECT "posts".* FROM "posts" WHERE "posts"."calendar_id" = ? [["calendar_id", 1]]
Rendered posts/_post.html.erb (0.7ms)
Rendered shared/_error_messages.html.erb (0.0ms)
Rendered shared/_post_form.html.erb (5.2ms)
Rendered calendars/show.html.erb within layouts/application (17.9ms)
Rendered layouts/_shim.html.erb (0.0ms)
User Load (0.1ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1 [["id", 1]]
Rendered layouts/_header.html.erb (0.8ms)
Rendered layouts/_footer.html.erb (0.3ms)
Completed 200 OK in 160ms (Views: 147.4ms | ActiveRecord: 0.8ms)
问题可能来自哪里：模型，表格，控制器或其他地方？
答案 0 :(得分：1)
你必须创建你的邮政参数。
class PostsController < ApplicationController
def create
@post = Post.create(post_params)
if @post.save
redirect_to root_url
else
render root_url
end
end
protected
def post_params
params.require(:post).permit(:date, :time, :focus....) #put all columns that you want to submit via form here.
end
end
您获得的内容很可能是验证错误，因为您可能需要为帖子提交至少一个字段。当rails没有收到此消息时，您会将其告知render而不是redirect，因此您可能不会注意到重新加载。