Rails

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have setup this HABTM relationship in the past and its worked before....Now it isnt and I'm at my wits end trying to figure out whats wrong. I've looking through the rails guides all day and cant seem to figure out what I'm doing wrong, so help would really be appreciated. I have 2 models connected through a join model and I'm trying to find records based an attribute of the associated model. Event.rb has_and_belongs_to_many :interests Interest.rb has_and_belongs_to_many :events and a join table migration that was created like create_table

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: Used https://rvm.beginrescueend.com/rvm/install/ to install ruby (ruby 1.9.2p290) & gems (no problems), then installed rails via gem install rails (Rails 3.2.0). But when I try and create a rails app (or issue rails -v ) in another directory other than my /user directory I get "The program 'rails' is currently not installed. You can install it by typing: sudo apt-get install rails" I also noticed that if I issue ruby -v I get "The program 'ruby' is currently not installed. You can install it by typing: sudo apt-get install ruby ". Obviously,

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I've tried to find some solution for this, but I really couldn't find anything related with the errors that is appearing to me when I run the rails command: rails generate model Book title:string summary:text isbn:string /home/vmu/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/gems/activesupport-5.0.1/lib/active_support/xml_mini.rb:51: warning: constant ::Fixnum is deprecated /home/vmu/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/gems/activesupport-5.0.1/lib/active_support/xml_mini.rb:52: warning: constant ::Bignum is deprecated /home/vmu/.rbenv

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm trying to install ROR on my notebook (Debian Wheezy 64 bit). On first I had this issue ( enter link description here ) solved by the first answer. Now the rails server starts, but surfing on the browser at localhost:3000 I get the following error: Could not load 'active_record/connection_adapters/sqlite3_adapter'. Make sure that the adapter in config/database.yml is valid. If you use an adapter other than 'mysql', 'mysql2', 'postgresql' or 'sqlite3' add the necessary adapter gem to the Gemfile. I've installed ruby 2.0.0 compiling the

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: None of the questions on this forum seem to address my specific need. Basically, I have a "Details" button. I want it that when it clicks, a modal dialog shows up with information drawn from the show.html.erb of the model. I have a book.rb model. In the index page I have: <div class="detail_button"><%= link_to "Details", book %></div> Clicking this button normally would take me to the book/id page, using the show action. But I don't want it to leave the page, rather I want a modal popup which can be closed. I've tried all the jquery and

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have a standard many-to-many relationship between users and roles in my Rails app: class User < ActiveRecord::Base has_many :user_roles has_many :roles, :through => :user_roles end I want to make sure that a user can only be assigned any role once. Any attempt to insert a duplicate should ignore the request, not throw an error or cause validation failure. What I really want to represent is a "set", where inserting an element that already exists in the set has no effect. {1,2,3} U {1} = {1,2,3}, not {1,1,2,3}. I realize that I can do it

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have read the documentation at http://api.rubyonrails.org/classes/ActiveRecord/Callbacks.html , but don't understand when the around_* callbacks are triggered in relation to before_* and after_* . Any help much appreciated. Thanks. 回答1: around_* callbacks are invoked before the action, then when you want to invoke the action itself, you yield to it, then continue execution. That's why it's called around The order goes like this: before , around , after . So, a typical around_save would look like this: def around_save #do something... yield

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: In my gemfile I have: gem 'mysql2' My database.yml is as follows: default: &default adapter: mysql2 database: <%= ENV['db_name'] %> username: <%= ENV['db_user'] %> password: <%= ENV['db_pass'] %> host: <%= ENV['db_host'] %> pool: 32 socket: <%= ENV['socket'] %> development: <<: *default production: <<: *default I've run both bundle update and bundle install and my Gemfile.lock shows mysql2. However when I run rake db:migrate I get this on both my computer and on the staging server: myproject.com(master)$ rake db:migrate WARNING: Use strings

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm trying to re-use an html component that i've written that provides panel styling. Something like: <div class="v-panel"> <div class="v-panel-tr"></div> <h3>Some Title</h3> <div class="v-panel-c"> .. content goes here </div> <div class="v-panel-b"><div class="v-panel-br"></div><div class="v-panel-bl"></div></div> </div> So I see that render takes a block. I figured then I could do something like this: # /shared/_panel.html.erb <div class="v-panel"> <div class="v-panel-tr"></div> <h3><%= title %></h3> <div class="v-panel-c"> <%= yield %> <

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: This question already has an answer here: What is the difference between in ERB in Rails? 5 answers I have started some rails tutorials and noticed that some of the view code blocks are like and other code blocks are like What is the difference between -%> and %> If you know of some good syntax references you can point me to, that would also be helpful. 回答1: The extra dash makes ERB not output the newline after the closing tag. There's no difference in your example, but if you have something like this: Hi It'll produce: Hi and not this: Hi