git memo

github 不知道為為啥我複製出來的網址是https 的
所以跑出 remote HEAD refers to nonexistent ref, unable to checkout. 的錯誤

git clone git@github.com:ooxx 這樣的才對

Railscast skill(9)

Complex Partials
Rendering partials with layouts
view 重複的部份 不只是裡面 也有可能是外面, render 的參數也可以代layout
Partials can have their own layouts applied to them. These layouts are different than the ones that are specified globally
for the entire action, but they work in a similar fashion. Imagine a list with two types of users:
<br /> <% render(:layout => "administrator", :locals => { :user => chief }) do %> <br /> Title: <%= chief.title %> <br /> <% end %> <br /><br /><br /> <!-- app/views/users/_administrator.html.erb --> <br /> <div id="administrator"> <br /> Budget: $<%= user.budget %> <br /> <%= yield if block_given? %><br /> </div> <br />

Customize Field Error
可以自訂error msg 的格式
# environment.rb<br />ActionView::Base.field_error_proc = Proc.new do |html_tag, instance_tag|<br /> "<span class='field_error'>#{html_tag}</span>"<br />end<br />

Railscast skill(8)

Logging Variables

eval 執行後面的 ruby code
binding 可以把當時的環境存起來
<br />irb(main):003:0> eval('1 + 2')<br />=> 3<br />irb(main):004:0> eval('[1] + [2]')<br />=> [1, 2]<br /><br /><br /># models/product.rb<br />logger.debug_variables(binding)<br /><br />#想替logger object 加 method, 可是因為需要當時的環境 來拿它的 local_variables 和 instance_variables<br /># config/initializers/logger_additions.rb<br />logger = ActiveRecord::Base.logger<br />def logger.debug_variables(bind)<br /> vars = eval('local_variables + instance_variables', bind)<br /> vars.each do |var|<br /> debug "#{var} = #{eval(var, bind).inspect}"<br /> end<br />end<br />

The Logger
message 四個等級 debug, info , error, fatal
development default 是 debug, 表示debug 以上的都可以看到, mysql instruction message 是在debug mode 所以 production 看不到
production 是 info
<br /># 可以自己overwrite message format<br /># environment.rb<br />Rails::Initializer.run do |config|<br /> config.active_record.colorize_logging = false<br />end<br /><br />class Logger<br /> def format_message(level, time, progname, msg)<br /> "#{time.to_s(:db)} #{level} -- #{msg}\n"<br /> end<br />end<br /><br /># 可以自己設定自己想看的level<br /># 或者是overwrite 掉 logger object<br /># environments/production.rb<br />config.log_level = :debug<br />config.logger = Logger.new(...) # or log4r<br /><br /><br />#讓你在console執行指令也可以看到 mysql output<br /># ~/.irbrc<br />if ENV.include?('RAILS_ENV') && !Object.const_defined?('RAILS_DEFAULT_LOGGER')<br /> require 'logger'<br /> RAILS_DEFAULT_LOGGER = Logger.new(STDOUT)<br />end<br />

YAML Configuration File

整理變數的好方法, 放在yml 裡, 還可以靠程式根據不同的環境load 進不同的變數
# config/initializers/load_config.rb<br />APP_CONFIG = YAML.load_file("#{RAILS_ROOT}/config/config.yml")[RAILS_ENV]<br /><br /># config/config.yml<br />development:<br /> perform_authentication: false<br /><br />test:<br /> perform_authentication: false<br /><br />production:<br /> perform_authentication: true<br /> username: admin<br /> password: secret<br />

Railscast skill (7)

in_groups_of
定量分組時在用的
<br /><!-- tasks/index.rhtml --><br /><table><br /><% @tasks.in_groups_of(4, false) do |row_tasks| %><br /> <tr><br /> <% for task in row_tasks %><br /> <td><%= task.name %></td><br /> <% end %><br /> </tr><br /><% end %><br /></table><br />

group_by Month
group_by 好棒, 想用啥分類就分
# tasks_controller.rb<br />def index<br /> @tasks = Task.find(:all, :order => 'due_at, id', :limit => 50)<br /> @task_months = @tasks.group_by { |t| t.due_at.beginning_of_month }<br />end<br /><br /><br /><!-- tasks/index.rhtml --><br /><% @task_months.sort.each do |month, tasks| %><br /> <h2><%= month.strftime('%B') %></h2><br /> <% for task in tasks %><br /> <div class="task"><br /> <strong><%= task.name %></strong><br /> due on <%= task.due_at.to_date.to_s(:long) %><br /> </div><br /> <% end %><br /><% end %><br />

Railscast skill (6)

Restricting Access

helper_method 可以把某些controller 的method 弄到helper 一起用
<br /><!-- episodes/index.rhtml --><br /><% if admin? %><br /> <%= link_to 'New Episode', new_episode_path %><br /><% end %><br /><br /># controllers/application.rb<br />helper_method :admin?<br /><br />protected<br /><br />def admin?<br /> false<br />end<br /><br />def authorize<br /> unless admin?<br /> flash[:error] = "unauthorized access"<br /> redirect_to home_path<br /> false<br /> end<br />end<br /><br /># episodes_controller.rb<br />before_filter :authorize, :except => :index<br />

Console Tricks<br /># 好一個 sandbox<br />ruby script/console --sandbox<br />Loading development environment in sandbox (Rails 2.2.2)<br />Any modifications you make will be rolled back on exit<br />>><br /><br /># 好一個 y<br />>> y User.first<br />--- !ruby/object:User <br />attributes: <br /> updated_at: 2009-09-10 06:45:46<br /> email_notify: "1"<br /> remember: "0"<br /> nickname: shlee<br /> id: "1"<br /><br /># helper<br />>> helper.text_field_tag :foo<br />=> "<input id=\"foo\" name=\"foo\" type=\"text\" />"<br /><br /># app 好物, hash_for_............ 好物<br />>> app.methods.grep(/_path$/)<br />>> app.homepage_path<br />=> "/"<br />>> app.hash_for_homepage_path<br />=> {:action=>"index", :only_path=>true, :controller=>"tc2", :use_route=>:homepage}<br /><br /># 可以自訂method 在 ~/.irbrc 裡<br />

Handling Exceptions
<br />#除了在 在product.rb 裡的設定<br />config.action_controller.consider_all_requests_local = false<br /><br />#還必須在application controller裡overwrite 掉 local_request? 這樣你在那邊用localhost:3000 它才會認出你是localhost 來的, 這樣才會丟500那種頁面給你<br /># 所以其實也可以在裡面多加上 admin 的判斷 如果是admin 的話 就讓它丟那種詳細的 error message<br /># application.rb<br />def local_request?<br /> false<br />end<br /><br />#要overwirte 一些exception 就可以在這用<br />def rescue_action_in_public(exception)<br /> case exception<br /> when ActiveRecord::RecordNotFound<br /> render :file => "#{RAILS_ROOT}/public/404.html", :status => 404<br /> else<br /> super<br /> end<br />end<br />

Catch-all Route
可以利用這招把所有奇怪的route 路徑都拿去 在controller 裡面在做些有的沒的處理
<br /># routes.rb<br />map.connect '*path', :controller => 'redirect', :action => 'index'<br /><br /># redirect_controller.rb<br />def index<br /> product = Product.find(:first, :conditions => ["name LIKE ?", "#{params[:path].first}%"])<br /> redirect_to product_path(product)<br />end<br />

Railscast skill (5)

Refactoring Out Helper Object

某些 method 需要很多其他的小 method 可是放在application helper 裡 又不是算大家都會用到的東西, 這時候就可以把它搬到外面弄成一個class,

<br /># application_helper.rb<br />def render_stars(rating)<br /> #傳self 進去<br /> StarsRenderer.new(rating, self).render_stars<br />end<br /><br /># helpers/stars_renderer.rb<br />class StarsRenderer<br /> def initialize(rating, template)<br /> @rating = rating<br /> @template = template<br /> end<br /> <br /> def render_stars<br /> content_tag :div, star_images, :class => 'stars'<br /> end<br /><br /> private<br /> <br /> def star_images<br /> (0...5).map do |position|<br /> star_image(((@rating-position)*2).round)<br /> end.join<br /> end<br /> <br /> def star_image(value)<br /> image_tag "/images/#{star_type(value)}_star.gif", :size => '15x15'<br /> end<br /> <br /> def star_type(value)<br /> if value <= 0<br /> 'empty'<br /> elsif value == 1<br /> 'half'<br /> else<br /> 'full'<br /> end<br /> end<br /> <br /> #好技巧<br /> def method_missing(*args, &block)<br /> @template.send(*args, &block)<br /> end<br />end<br />


Site Wide Announcements
又用了controller 的 javascripts 的技巧 不過這邊這個要注意一下 route 要加上format

<br /><!-- layouts/application.html.erb --><br /># helper method 後面直接可以接method ㄟ 棒<br /><% unless current_announcements.empty? %><br /><div id="announcement"><br /> <% for announcement in current_announcements %><br /> <p><%=h announcement.message %></p><br /> <% end %><br /> <p><%= link_to_remote "Hide this message", :url => "/javascripts/hide_announcement.js" %></p><br /></div><br /><% end %><br /><br /># models/announcement.rb<br /># 注意一下with_scope 用法<br />def self.current_announcements(hide_time)<br /> with_scope :find => { :conditions => "starts_at <= now() AND ends_at >= now()" } do<br /> if hide_time.nil?<br /> find(:all)<br /> else<br /> find(:all, :conditions => ["updated_at > ? OR starts_at > ?", hide_time, hide_time])<br /> end<br /> end<br />end<br /><br /># application_helper.rb<br /># 直接用session 來記有沒有看過 GOOD<br />def current_announcements<br /> @current_announcements ||= Announcement.current_announcements(session[:announcement_hide_time])<br />end<br /><br /># javascripts_controller.rb<br />def hide_announcement<br /> session[:announcement_hide_time] = Time.now<br />end<br /><br /># hide_announcement.js.rjs<br />page[:announcement].hide<br /><br /># routes.rb<br />map.connect ":controller/:action.:format"<br />

Railscast skill (4)

Pretty Page Title

把content_for 弄簡潔了, yield 也要有default
<br /># application_helper.rb<br />def title(page_title)<br /> content_for(:title) { page_title }<br />end<br /><br /><br /><!-- layouts/application.rhtml --><br /><[title>Shoppery - <%= yield(:title) || "The Place to Buy Stuff" %></title]><br />

Markaby in Helper
也可以在helper 裡用render :partial 或者是用content_tag 去拼view
<br /># in helper<br />def simple_error_messages_for(object_name)<br /> object = instance_variable_get("@#{object_name}")<br /> return if object.errors.empty?<br /> <br /> markaby do<br /> div.error_messages! do<br /> h2 "#{pluralize(object.errors.count, 'error')} occurred"<br /> p "There were problems with the following fields:"<br /> ul do<br /> object.errors.each_full do |msg|<br /> li msg<br /> end<br /> end<br /> end<br /> end<br />end<br /><br />def markaby(&block)<br /> Markaby::Builder.new({}, self, &block)<br />end<br />