我正在研究RailsGuides教程(创建一个博客应用程序).当我运行服务器并打开时:/posts/new一切看起来都很好.但是,当我尝试创建帖子时,我收到此错误:
帖子#show中的NoMethodError
显示/home/darek/rails_projects/blog/app/views/posts/show.html.erb在行#3提出:
nil的未定义方法`title':NilClass
提取的来源(第3行):
1 <p>
2 <strong>Title:</strong>
3 <%= @post.title %>
4 </p>
5 <p>
事实上post已创建,我可以在/ posts看到标题和内容但是当我尝试使用show特定帖子时,我收到此错误.我的第一个线索就是换线
<%= @post.title %>
至
<%= @post.try(:title) %>
错误消失了,但问题没有解决.
当我尝试显示特定帖子时,我获得了标题,而文本形式为空.这不是我想要看到的;)
好的,这是代码
Show.html.erb
<p>
<strong>Title:</strong>
<%= @post.title %>
</p>
<p>
<strong>Text:</strong>
<%= @post.text %>
</p>
<h2>Add a comment:</h2>
<%= form_for([@post, @post.comments.build]) do |f| %>
<p>
<%= f.label :commenter %><br />
<%= f.text_field :commenter %>
</p>
<p>
<%= f.label :body %><br />
<%= f.text_area :body %>
</p>
<p>
<%= f.submit %>
</p> …当我运行:rake db:setup
我得到:
fe_sendauth: no password supplied
Couldn't create database for {"adapter"=>"postfresql", "encoding"=>"unicode",
"host"=>"localhost", "pool"=>5, "username"=>"my_user", "password"=>nil,
"database"=>"my_db_test"}
-- enable_extension("plpgqsl")
rake aborted
Tasks: TOP => db:schema:load
我的database.yml:
connection: &connection
adapter: postgresql
encoding: unicode
host: localhost
pool: 5
username: my_user
password:
development:
<<: *connection
database: my_db_development
test: &test
<<: *connection
database: my_db_test
已经在这个问题中更改了我的pg_hba.conf:尝试为ror应用程序设置postgres,收到错误 - fe_sendauth:没有提供密码 但它根本没有帮助.
这是我的问题.我正在尝试创建一个博客.我运行'rails new blog'.Everythign没问题,直到我尝试'rake db:create'.它返回一个错误:
rake aborted!
Please install the postgresql adapter: `gem install activerecord-postgresql-adap
ter` (pg is not part of the bundle. Add it to Gemfile.)
当我尝试安装pg适配器时,我得到了这个:
Temporarily enhancing PATH to include DevKit...
Building native extensions. This could take a while...
ERROR: Error installing activerecord-postgresql-adapter:
ERROR: Failed to build gem native extension.
F:/Ruby200-x64/bin/ruby.exe extconf.rb
checking for pg_config... no
No pg_config... trying anyway. If building fails, please try again with
--with-pg-config=/path/to/pg_config
checking for libpq-fe.h... no
Can't find the 'libpq-fe.h header
*** …当我运行服务器浏览器时显示如下:
Routing Error
No route matches [GET] "/static_pages/home"
Try running rake routes for more information on available routes.
耙路线告诉我这个:
root / static_pages#home
help /help(.:format) static_pages#help
about /about(.:format) static_pages#about
contact /contact(.:format) static_pages#contact
我的routes.rb文件:
MyApp::Application.routes.draw do
root :to => 'static_pages#home'
match '/help', :to => 'static_pages#help'
match '/about', :to => 'static_pages#about'
match '/contact', :to =>'static_pages#contact'
end
有人有个主意吗？
我的问题可能很简单,但我无法在任何地方找到答案.
创建类时,例如:
class Book
@author = "blabla"
@title = "blabla"
@number_of_pages"
我想创建一个方法来打印我的变量.我尝试时遇到问题:
def Print
puts @author, @title, @number_of_pages
end
我一无所获.
当我尝试:
def Print
puts "@author, @title, @number_of_pages"
end
我直截了当:"@ author,@ title,@ number_of_pages"
如何使Print方法打印出变量的值？
我需要创建一个包含 20 个随机数的文件。我试过这个：
for i in {1..20}; do n=$RANDOM; echo "no $i $n">random number;done
影响：
生成了数字，但它们不在文件中。我的错误在哪里？
我和Michael Hartl的教程一起工作.目前我在第10章.在第10.28部分,当我尝试运行测试时:
bundle exec rspec spec/requests/authentication_pages_spec.rb
我收到此错误:
Failures:
2) Authentication authorization for non-signed-in users in the Microposts
controller submitting to the destroy action Failure/Error: before { delete
microposts_path (FactoryGirl.create(:micropost)) } ActionController::RoutingError:
No route matches [DELETE] "/microposts.1"
# ./spec/requests/authentication_pages_spec.rb:115:in`block(6 levels) in
<top required)>'
这是我的authentication_pages_spec.rb:
require 'spec_helper'
describe "Authentication" do
let(:user) { FactoryGirl.create(:user) }
subject { page }
describe "signin page" do
before { visit signin_path }
it { should have_selector('h1', text: 'Sign in') }
it { should have_selector('title', text: …我有一个像这样的字符串:
"John Godson Michael Meyer Ludovicio Sforza Cezar Borgia Alessandro Batista"
如何将此字符串转换为字符串数组
# ["John", "Godson", "Michael Meyer" (...)]