ubuntu, ror, jQuery, css, website memo

RuntimeError: !!! Missing the mysql2 gem

2011-04-25T11:09:00.001+08:00

Rails 3 install mysql2 gem fail

production:
adapter: mysql2
encoding: utf8
reconnect: false
database: blog
pool: 5
username: root
password:
socket: /var/run/mysqld/mysqld.sock

Change the adapter, and find your socket file

rails + rubber + github + amazon ec2 free tier step by step

2011-04-20T15:45:00.017+08:00

Reference:
Rubber wiki : https://github.com/wr0ngway/rubber/wiki/

How to deploy a Rails app to EC2 in less than an hour using Rubber

http://ginzametrics.com/deploy-rails-app-to-ec2-with-rubber.html

Step 1: Amazon Registration
http://www.amazon.com/gp/aws/registration/registration-form.html

reference: http://www.inside.com.tw/2010/11/02/amazon-aws-1

Step 2: Check
You could check your amazon account status here, your billing
https://aws-portal.amazon.com/gp/aws/developer/account/index.html

Amazon service console
https://console.aws.amazon.com/ec2/home

Amazon Security Credentials, you could get your keys here
https://aws-portal.amazon.com/gp/aws/developer/account/index.html?ie=UTF8&action=access-key

Step 3: Get your key pair
https://console.aws.amazon.com/ec2/home?region=us-east-1#s=KeyPairs
You will download a private key here like : keyname.pem

Step 4: Install rubber in your project
sudo gem install rubber
rails generate vulcanize complete_passenger_mysql

Step 5: Generate your public key in ~/.ec2
Change keyname.pem to keyname
chmod 400 keyname
ssh-keygen -y -f keyname > exviewkey.pub

Step 6: Edit your config/rubber/rubber.yml

1)
cloud_providers → aws → access_key
cloud_providers → aws → secret_access_key
cloud_providers → aws → account
cloud_providers → aws → keyname
cloud_providers → aws → keyname_file_location

access_key: ABCDEFGHIJKLMNOPQRST
secret_access_key: ABCDEFGHIJKLMNOPQRSTUVWXY1234567890+zabc
account: 123456789012 #account original would show like 1234-5678-9012
key_name: exviewkey #the name of private key you download
key_file: "#{Dir[(File.expand_path('~') rescue '/root') + '/.ec2/*' + cloud_providers.aws.key_name].first}"

2) Change the server timezone, and domain
timezone: US/Pacific
domain: webiste.com

3) Change your image type
image_type: t1.micro
image_id: 'ami-3e02f257'

It is my image type, you could find more in

http://uec-images.ubuntu.com/releases/10.10/release/
http://uec-images.ubuntu.com/releases/10.04/release/
http://aws.amazon.com/amis/Linux?browse=1
http://cloud.ubuntu.com/ami/

Reference:
http://groups.google.com/group/rubber-ec2/browse_thread/thread/dfff07e016a28896

4) Change the app_user, app_name
app_user: www-data
app_name: websitename

Step 7: Edit deploy.rb
ssh_options[:forward_agent] = true #optional : for deploy from github
set :repository, "git@github.com:yourname/projectname.git"
set :scm, "git"
set :deploy_via, :remote_cache
set :branch, 'master'

Reference:
http://groups.google.com/group/rubber-ec2/browse_thread/thread/bdf75bebb38eec2a/23fac77708767390?lnk=gst&q=github#23fac77708767390

Step 8: set ssh-agent (optional : for deploy from github)
eval `ssh-agent -s`
ssh-add

Reference:
http://groups.google.com/group/rubber-ec2/browse_thread/thread/73e50e32264768f6/ee1b4f497d621797?lnk=gst&q=github#ee1b4f497d621797
http://www.josephj.com/article/understand-ssh-key/

Step 9: deploy (Finally Gook Luck :p )
cap rubber:create_staging

fb comment

2010-12-13T12:32:00.002+08:00

http://developers.facebook.com/docs/reference/plugins/comments

Unique ID 填了反而不行用是怎樣 = =

rails 設定多個 smtp account 寄信

2010-06-30T17:38:00.002+08:00

Using multiple SMTP accounts with Rails & ActionMailer

可利用此技巧, 達到多SMTP 寄信的目的

#action_mailer.yml production: website1: domain: "gary@superfriends.com" user_name: gary password: superduper address: smtp.gmail.com port: 587 authentication: :plain website2: domain: mysupercooldomain.com user_name: ABCDEF password: blahblah address: mail.authsmtp.com port: 25 authentication: :plain #app/models/mailer1.rb class Website1 < ActionMailer::Base def load_settings options = YAML.load_file("#{RAILS_ROOT}/config/action_mailer.yml")[RAILS_ENV]["website1"] @@smtp_settings = { :address => options["address"], :port => options["port"], :domain => options["domain"], :authentication => options["authentication"], :user_name => options["user_name"], :password => options["password"] } end def welcome_email(recipient, sent_at = Time.now) load_settings @subject = 'Thank you for visiting website 1' @recipients = RAILS_ENV == "production" ? recipient : "cavneb@gmail.com" @from = 'gary@superfriends.com' @sent_on = sent_at end end

haproxy nginx passenger munin

2010-06-24T17:37:00.007+08:00

step1: nginx need stub_status_module
compile with [--with-http_stub_status_module]

step2: install munin
sudo apt-get install munin munin-node

 
#/etc/munin/munin.conf
#This will tell munin to connect to munin-node at 127.0.0.1 on the same machine.
[foo.net]
    address 127.0.0.1
    use_node_name yes


#Edit the file /etc/munin/munin-node.conf and change # Which port to bind to set
host 127.0.0.1

#Make sure that this is present in the file

allow ^127\.0\.0\.1$

http://github.com/barttenbrinke/munin-plugins-rails
http://www.alfajango.com/blog/how-to-monitor-your-railspassenger-app-with-munin/
http://github.com/jnstq/munin-nginx-ubuntu

 
#haproxy setting
reqisetbe       ^Host:\ munin.foo.net        foomunin

#nginx config
server {
   listen 6166; 
   server_name munin.foo.net;
   root /home/foo/deploy/shared/directory/munin;   
}


#/etc/munin/plugin-conf.d/munin-node
[foo_*]
env.log_file '/home/foo/app/production.log'
user foo
command /opt/ruby-enterprise-1.8.7-2010.02/bin/ruby %c
env.graph_category Foo

rails ip 辨識國家

2010-06-22T17:09:00.004+08:00

how-to-know-user-location-with-rails
github geoip
Super fast IP to lat/lng in Rails

下載點 http://geolite.maxmind.com/download/geoip/database/

haproxy rails ip

2010-06-22T14:49:00.003+08:00

haproxy不能正確記錄客戶端的IP
關於 rails 的扔remote_ip
http://kkito.cn/index.php/blog/getArticle/102/rails%E4%B8%AD%E5%BA%94%E6%B3%A8%E6%84%8F%E5%8F%AF%E8%83%BD%E5%AE%A2%E6%88%B7%E7%AB%AFip%E5%9C%B0%E5%9D%80%E6%98%AF%E4%BC%AA%E8%A3%85%E7%9A%84

capistrano path rake fail

2010-06-21T15:35:00.006+08:00

http://blog.zerobearing.com/2009/04/27/capistrano-rake-command-not-found/
http://stackoverflow.com/questions/588934/using-ruby-enterprise-edition-gems-are-not-installed-where-i-would-expect
http://forum.slicehost.com/comments.php?DiscussionID=3657
http://stackoverflow.com/questions/257616/sudo-changes-path-why
http://groups.google.com/group/emm-ruby/browse_thread/thread/d0c685bbd096823a#msg_effa7d6ad42c541c
http://www.f15ijp.com/2009/11/30/sudo-no-tty-present-and-no-askpass-program-specified/

/etc/ssh/sshd_config:

PermitUserEnvironment yes
/etc/init.d/sshd restart

~/.ssh/environment
PATH=/opt/ruby-enterprise-1.8.7-2010.02/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games

http://formatinternet.wordpress.com/2009/07/06/sudo-rake-command-not-found/
~/.bashrc
alias sudo='sudo env PATH=$PATH'

sudo ln -s `which rake` /usr/local/bin/

#sudo: no tty present and no askpass program specified error
the /etc/sudoers file.
#commend sudo visudo
Defaults visiblepw

delayed_job capistrano production fail

2010-06-13T17:12:00.002+08:00

主要參考
http://railscasts.com/episodes/171-delayed-job
http://www.magnionlabs.com/2009/2/28/background-job-processing-in-rails-with-delayed_job

不知道哪邊弄錯了用capistrano deploy 想啟動delayed_job 卻好像都沒反應
後來終於看到有script/delayed_job run的指令這個動作才可以讓你看到你錯在哪, start 只會無聲無息

rmagic cannot open shared object file: No such file or directory

2010-06-10T18:30:00.003+08:00

libMagickCore.so.* cannot open shared object file: No such file or directory

http://github.com/jnstq/rails-nginx-passenger-ubuntu

To get rid of this error i executed

ldconfig /usr/local/lib

nginx passenger config

2010-06-03T14:04:00.006+08:00

nginx, worker_processes, and passenger_max_pool_size
Production Rails Tuning with Passenger: PassengerMaxProcesses

 
worker_processes 4;    <= Setting the number of Nginx workers to the number of CPU cores should be sufficient. 

http { 
passenger_max_pool_size 20; # memory 256M should be 2,  2G should be 30, max_pool 不要設太大, 不要讓它吃到swap,  free -ml ;  vmstat 2  都可以看到現在memory 的情況
passenger_max_instances_per_app 15; #每種ap 能用到最多的instance, 所以如果跑兩個app 就會再少一點

# PassengerPoolIdleTime
# Recommended to be avg time per page * 2
# In Google Analytics... (Avg time on site / Avg page views) * 2
# Default: 300
passenger_pool_idle_time 144

 }

超小型web server 設定
How to save MUCH RAM when running rails (linode/slicehost) and mod_rails passenger

改變預設的cache 目錄

2010-05-07T14:40:00.004+08:00

http://railsforum.com/viewtopic.php?id=11033

[Ptt][心得] Restful下遇到params[:id]含有.的解法

2010-04-20T17:49:00.000+08:00

在restful的前提下, 遇到class的to_param是字串, 而剛好某筆
紀錄的to_param欄位含有.

一般情形下會發生錯誤, 因為restful會把.後的東西當成format
這時的解法, 變成要在routes.rb中的xxx.resources加上參數

ex:

paramter change permanently, header status

2010-04-20T16:39:00.003+08:00

Practical Rails Social Networking Site memo (2)

2010-04-16T01:59:00.002+08:00

Practical Rails Social Networking Site memo

2010-04-15T15:00:00.003+08:00

#Ch2 def to_param "#{id}-#{permalink}" end def show @page = Page.find(params[:id].to_i) end #Some database servers (including MySQL) will automatically do this conversion for you. However,PostgreSQL and some others do not, so it is a good idea to add this to your controllers. You could also overridean ActiveRecord method #Ch3 module LoginSystem protected def is_logged_in? @logged_in_user = User.find(session[:user]) if session[:user] end def logged_in_user return @logged_in_user if is_logged_in? end def logged_in_user=(user) if !user.nil? session[:user] = user.id @logged_in_user = user end end def self.included(base) base.send :helper_method, :is_logged_in?, :logged_in_user end end map.show_user '/user/:username',:controller => 'users',:action => 'show_by_username' map.resources :users, :member => { :enable => :put } <ul><%= render :partial => 'role', :collection => @user.roles %></ul> <h2>Roles available:</h2> <ul><%= render :partial => 'role', :collection => (@all_roles - @user.roles) %></ul> #Ch4 def self.up create_table :categories do |t| t.column :name, :string end news_category = Category.create(:name => 'Site News') change_column :articles, :category_id, :integer, :default => news_category end def self.down change_column :articles, :category_id, :integer, :default => 0 drop_table :categories end def get_http_auth_data username, password = nil, nil auth_headers = ['X-HTTP_AUTHORIZATION', 'Authorization', 'HTTP_AUTHORIZATION', 'REDIRECT_REDIRECT_X_http_AUTHORIZATION'] auth_header = auth_headers.detect { |key| request.env[key] } auth_data = request.env[auth_header].to_s.split if auth_data && auth_data[0] == 'Basic' username, password = Base64.decode64(auth_data[1]).split(':')[0..1] end return [username, password] end @request.env['HTTP_ACCEPT'] = 'application/xml' @request.env['Authorization'] = 'Basic ' + Base64::b64encode('editor:12345')

check timezone valid

2010-04-06T10:51:00.001+08:00

migration

2010-03-21T22:43:00.003+08:00

rjs page

2010-03-10T10:33:00.001+08:00

page['foo']['style']
# => $('foo').style;
page['foo']['style']['color']
# => $('blank_slate').style.color;
page['foo']['style']['color'] = 'red'
# => $('blank_slate').style.color = 'red';
page['foo']['style'].color = 'red'
# => $('blank_slate').style.color = 'red';

respond_to jsonp

2010-03-10T10:28:00.001+08:00

respond_to recognizes • JSON.
render :json => @person.to_json automatically sets the content type and takes a :callback option to specify a client-side function to call using the rendered JSON as an argument. #4185 [Scott Raymond, eventualbuddha]

Bootstrap Initializer

2010-03-10T10:08:00.001+08:00

Bootstrap Initializer
The files in config/initializers are loaded after Rails' environment is loaded (including environment.rb). However, there's a pre-environment
hook provided for you should you need to do things prior to Rails' environment getting in the mix: just create a config/preinitializer.rb file.

This file is loaded after the Rails classes are loaded but before the environment file and the environment configuration.

rescue_from Exception Handlers

2010-03-09T17:01:00.002+08:00

rescue_from Exception Handlers

class PostsController < ApplicationController def rescue_action_in_public(exception) case(exception) when ActiveRecord::RecordNotFound render :file => '/bad_record' when NoMethodError render :file => '/no_method' else render :file => '/error' end end end #====================================== class PostsController < ApplicationController # Declare exception to handler methods rescue_from ActiveRecord::RecordNotFound, :with => :bad_record rescue_from NoMethodError, :with => :show_error # Define handler methods def bad_record render :file => '/bad_record' end def show_error(exception) render :text => exception.message end end #====================================== class PostsController < ApplicationController rescue_from(ActiveRecord::RecordNotFound) do |exception| render :file => '/bad_record' end rescue_from NoMethodError, :with => proc do |e| render :text => e.message end end

Top 8 SQL Best Practices

2010-03-05T16:53:00.002+08:00

Top 8 SQL Best Practices

1) Always use explicit joins. If I mean INNER JOIN, then I use INNER JOIN. No use of just plain "JOIN". Never, ever, ever use a comma join -- I consider that a mistake. If I explicitly state "CROSS JOIN" then I know I have consciously made that decision. Also, keep join conditions in an ON or USING clause; they should not go in the WHERE clause. I also put my join conditions in parentheses; for whatever reason, I find:
ON (foo=bar AND baz=bop) WHERE a=b
is easier to see that the join condition contains 2 conditions than
ON foo=bar AND baz=bop WHERE a=b

SQL Server TSQL Coding Conventions, Best Practices, and Programming Guidelines

2010-03-05T16:14:00.002+08:00

SQL Server TSQL Coding Conventions, Best Practices, and Programming Guidelines

Try to avoid wildcard characters at the beginning of a word while searching using the LIKE keyword, as that results in an index scan, which defeats the purpose of an index. The following statement results in an index scan, while the second statement results in an index seek:

SELECT LocationID FROM Locations WHERE Specialities LIKE '%pples'
SELECT LocationID FROM Locations WHERE Specialities LIKE 'A%s'

Also avoid searching using not equals operators (<> and NOT) as they result in table and index scans.

Use 'Derived tables' wherever possible, as they perform better. Consider the following query to find the second highest salary from the Employees table:

SELECT MIN(Salary)
FROM Employees
WHERE EmpID IN
(
SELECT TOP 2 EmpID
FROM Employees
ORDER BY Salary Desc
)

The same query can be re-written using a derived table, as shown below, and it performs twice as fast as the above query:

SELECT MIN(Salary)
FROM
(
SELECT TOP 2 Salary
FROM Employees
ORDER BY Salary DESC
) AS A

This is just an example, and your results might differ in different scenarios depending on the database design, indexes, volume of data, etc. So, test all the possible ways a query could be written and go with the most efficient one.

While designing your database, design it keeping "performance" in mind. You can't really tune performance later, when your database is in production, as it involves rebuilding tables andindexes, re-writing queries, etc. Use the graphical execution plan in Query Analyzer or SHOWPLAN_TEXT or SHOWPLAN_ALL commands to analyze your queries. Make sure your queries do an "Index seek" instead of an "Index scan" or a "Table scan." A table scan or an index scan is a very bad thing and should be avoided where possible. Choose the right indexes on the right columns.

Use the more readable ANSI-Standard Join clauses instead of the old style joins. With ANSI joins, the WHERE clause is used only for filtering data. Where as with older style joins, the WHERE clause handles both the join condition and filtering data. The first of the following two queries shows the old style join, while the second one shows the new ANSI join syntax:

SELECT a.au_id, t.title
FROM titles t, authors a, titleauthor ta
WHERE
a.au_id = ta.au_id AND
ta.title_id = t.title_id AND
t.title LIKE '%Computer%'

SELECT a.au_id, t.title
FROM authors a
INNER JOIN
titleauthor ta
ON
a.au_id = ta.au_id
INNER JOIN
titles t
ON
ta.title_id = t.title_id
WHERE t.title LIKE '%Computer%'

rails performance memo

2010-03-05T12:23:00.001+08:00

That’s Not a Memory Leak, It’s Bloat; refactor

2010-03-03T15:00:00.002+08:00

That’s Not a Memory Leak, It’s Bloat

respond_to

2010-03-03T12:08:00.002+08:00

#=============================================== class ApplicationController < ActionController::Base before_filter :adjust_format_for_iphone helper_method :iphone_user_agent? protected def adjust_format_for_iphone request.format = :iphone if iphone_user_agent? || iphone_subdomain? end # Request from an iPhone or iPod touch? # (Mobile Safari user agent) def iphone_user_agent? request.env["HTTP_USER_AGENT" ] && request.env["HTTP_USER_AGENT" ][/(Mobile\/.+Safari)/] end def iphone_subdomain? return request.subdomains.first == "iphone" end end # ======================= # custom format # config/initializers/mime_types.rb Mime::Type.register ‘audio/mpeg’, :mp3?Mime::Type.register ‘audio/mpegurl’, :m3u def show @mp3 = Mp3.find(params[:id]) respond_to do |format| format.html format.mp3 { redirect_to @mp3.url } format.m3u { render :text => @mp3.url } end end #======================== def index @users = User.find(:all) respond_to do |format| format.js { render :update do |page| page.replace_html ‘content’, ‘blah’ end } format.html #index.html.erb end end

Restful memo

2010-03-03T10:55:00.007+08:00

#RESTful controller 一定是複數結尾 map.resources :events do |event| event.resource :map, :controller => ‘event_maps’ end #============================================= # 之前用的笨方法 map.resources :orders, :path_prefix => "/admin", :controller => "admin/orders" # 其實有namespace map.namespace :admin do |admin| admin.resources :events end # /app/controllers/admin/events_controller.rb class Admin::EventsController < ApplicationController before_filter :require_admin def index .... end end #============================================ =begin Considerations(1) a REST resource does not map directly to model. It’s high-level abstractions of what’s available through your web app. (Not always 1-to-1, maybe 1-to-many or 1-to-zero) • You don’t need to use all 7 actions if you don’t need them. Considerations(2) a RESTful controller may represent the creation or delete of only a concept. For example, a SpamsController create spam by changing a comment’s status to spam without adding any records to the DB. Considerations(3) one resources should be associated with one controller. (well, you can use one controller handle more than one resources) • offload privileged views into either a different controller or action. =end #================================== #for event manager map.resources :attendees class AttendeeController < ApplicationController before_filter :manager_required def show @person = @event.attendees.find(params[:id]) end end #for attendeeing user map.resources :registers class RegistersController < ApplicationController before_filter :login_required def show @person = current_user.registers.find(params[:id]) end end 1 attendee Model 2 Resources related (2 Controller) #============================================== # http://ryandaigle.com/articles/2008/11/27/what-s-new-in-edge-rails-no-more-formatted-routes # Old => New formatted_article_path(article, :xml) => article_path(article, :format => :xml) formatted_new_article_path(:json) => new_article_path(:format => :json) # etc...

Rails Best Practices

2010-03-02T10:34:00.002+08:00

Rails Best Practices

#Before <% form_for @user do |f| %> <%= f.text_field :email %> <% for role in Role.all %> <%= check_box_tag 'role_id[]', role.id, @user.roles.include?(role) %> <%= role.name %> <% end %> <% end %> class User < ApplicationController def update @user = User.find(params[:id]) if @user.update_attributes(params[:user]) @user.roles.delete_all (params[:role_id] || []).each { |i| @user.roles << Role.find(i) } end end end #After <% form_for @user do |f| %> <% for role in Role.all %> <%= check_box_tag 'user[role_ids][]', role.id, @user.roles.include?(role) <%= role.name %> <% end %> <%= hidden_field_tag 'user[role_ids][]', '' %> <% end %> class User < ApplicationController def update @user = User.find(params[:id]) @user.update_attributes(params[:user]) # @user.role_ids = params[:user][:role_ids] end end #========================================== #Nested Model Forms (one-to-one) Before class Product < ActiveRecord::Base has_one :detail end class Detail < ActiveRecord::Base belongs_to :product end <% form_for :product do |f| %> <%= f.text_field :title %> <% fields_for :detail do |detail| %> <%= detail.text_field :manufacturer %> <% end %> <% end %> class Product < ApplicationController def create @product = Product.new(params[:product]) @details = Detail.new(params[:detail]) Product.transaction do @product.save! @details.product = @product @details.save! end end end # ~~~~~~~~~~~~~~~~~~~~~~~~~ # Nested Model Forms (one-to-one) After Rails 2.3 new feature class Product < ActiveRecord::Base has_one :detail accepts_nested_attributes_for :detail end <% form_for :product do |f| %> <%= f.text_field :title %> <% f.fields_for :detail do |detail| %> <%= detail.text_field :manufacturer %> <% end %> <% end class Product < ApplicationController def create @product = Product.new(params[:product]) @product.save end end #Nested Model Forms (one-to-many) class Project < ActiveRecord::Base has_many :tasks accepts_nested_attributes_for :tasks end class Task < ActiveRecord::Base belongs_to :project end <% form_for @project do |f| %> <%= f.text_field :name %> <% f.fields_for :tasks do |tasks_form| %> <%= tasks_form.text_field :name %> <% end %> <% end %> #=========================================== #Extract into Module Before class User < ActiveRecord::Base validates_presence_of :cellphone before_save :parse_cellphone def parse_cellphone # do something end end # /lib/has_cellphone.rb module HasCellphone def self.included(base) base.validates_presence_of :cellphone base.before_save :parse_cellphone base.send(:include,InstanceMethods) base.send(:extend, ClassMethods) end module InstanceMethods def parse_cellphone # do something end end module ClassMethods end end class User < ActiveRecord::Base include HasCellphone end #======================================= # Extract to composed class Before # == Schema Information # address_city :string(255) # address_street :string(255) class Customer < ActiveRecord::Base def adddress_close_to?(other_customer) address_city == other_customer.address_city end def address_equal(other_customer) address_street == other_customer.address_street && address_city == other_customer.address_city end end #Extract to composed class (value object) After class Customer < ActiveRecord::Base composed_of :address, :mapping => [ %w(address_street street), %w(address_city city) ] end class Address attr_reader :street, :city def initialize(street, city) @street, @city = street, city end def close_to?(other_address) city == other_address.city end def ==(other_address) city == other_address.city && street == other_address.street end end # Isolating Seed Data # Before class CreateRoles < ActiveRecord::Migration def self.up create_table "roles", :force => true do |t| t.string :name end #Move this to db/seeds.rb ["admin", "author", "editor","account"].each do |name| Role.create!(:name => name) end end def self.down drop_table "roles" end end # After # /db/seeds.rb (Rails 2.3.4) ["admin", "author", "editor","account"].each do |name| Role.create!(:name => name) end rake db:seed

Advanced Active Record Techniques: Best Practice Refactoring

2010-03-01T17:39:00.003+08:00

Advanced Active Record Techniques: Best Practice Refactoring

#p54 class ArticleVersion < ActiveRecord::Base before_validation_on_create :set_version_number before_create :mark_related_links_not_current, :if => :current_version private def current_version article.current_version end #下面兩個method 都會call 到 article.current_version #這樣就可以抽出來 #然後mark_related_linkers_not_current 會需要判斷 article.current_version 的存在與否這也可以利用 Conditional Callback 來判斷 def set_version_number self.version = (current_version ? current_version.version : 0) + 1 end def mark_related_links_not_current current_version.relateds.each do |rel| rel.update_attribute(:current, false) end end end #================================================================ #p74 class ArticleVersion < ActiveRecord::Base STATES = { :edit => 'Edit', :edit_check => 'Edit Check', :sub_edit => 'Sub Edit', :publish_ready => 'Publish Ready', :published => 'Published' } STATES.each do |key, value| define_method "#{key}?", { self.state == "#{value}" } end end #========================================================= # p84 class Role < ActiveRecord::Base has_and_belongs_to_many :users validates_presence_of :name validates_uniqueness_of :name def name=(value) write_attribute("name", value.downcase) end # 想用symbol 拿值 def self.[](name) # Get a role quickly by using: Role[:admin] self.find(:first, :conditions => ["name = ?", name.id2name]) end def add_user(user) self.users << user end def delete_user(user) self.users.delete(user) end end #==================================================== # p91 class User < ActiveRecord::Base has_many :roles end class Role < ActiveRecord::Base TYPES = %w(admin editor writer guest) validates_inclusion_of :name, :in => TYPES # 生成 class method class << self TYPES.each do |role_type| define_method "#{role_type}?" do # Exists? http://api.rubyonrails.org/classes/ActiveRecord/Base.html#M002268 roles.exists?(:name => role_type) end end end end # ===================================================== # p96 # Step 1 class User < ActiveRecord::Base include Addressable end class Order < ActiveRecord::Base include Addressable end module Addressable def self.included(base) base.validates_presence_of :billing_address_one, :billing_city, :billing_state, :billing_zip, :billing_country base.validates_presence_of :shipping_address_one, :shipping_city, :shipping_state, :shipping_zip, :shipping_country base.validates_format_of :billing_zip, :with => /\d{5}(-\d{4})?/, :if => Proc.new { |klass| klass.billing_country == "US" } base.validates_format_of :shipping_zip, :with => /\d{5}(-\d{4})?/, :if => Proc.new { |klass| klass.shipping_country == "US" } base.validates_format_of :billing_zip, :with => /[a-zA-Z]\d[a-zA-Z] \d[a-zA-Z]\d/, :if => Proc.new { |klass| klass.billing_country == "CA" } base.validates_format_of :shipping_zip, :with => /[a-zA-Z]\d[a-zA-Z] \d[a-zA-Z]\d/, :if => Proc.new { |klass| klass.shipping_country == "CA" } end end # Step 2 class User < ActiveRecord::Base has_address :shipping has_address :billing has_many :orders end module Addressable class << self def included(base) base.extend ClassMethods end end module ClassMethods def has_address(name = "") name = "#{name}_" unless name.blank? validates_presence_of "#{name}address_one", "#{name}city", "#{name}state_province", "#{name}postal_code", "#{name}country" validates_format_of "#{name}postal_code", :with => /\d{5}(-\d{4})?/, :if => Proc.new { |user| user["#{name}country"] == "US" } validates_format_of "#{name}postal_code", :with => /[a-zA-Z]\d[a-zA-Z] \d[a-zA-Z]\d/, :if => Proc.new { |user| user["#{name}country"] == "CA" } end end end ActiveRecord::Base.send :include, Addressable # Step 3 class User < ActiveRecord::Base has_address :shipping has_address :billing has_many :orders end module Addressable class << self def included(base) base.extend ClassMethods end end module ClassMethods def has_address(name) name << “_” unless name.blank? validates_presence_of "#{name}address_one", "#{name}city", "#{name}state_province", "#{name}postal_code", "#{name}country" validates_format_of "#{name}postal_code", :with => /\d{5}(-\d{4})?/, :if => Proc.new { |user| user["#{name}country"] == "US" } validates_format_of "#{name}postal_code", :with => /[a-zA-Z]\d[a-zA-Z] \d[a-zA-Z]\d/, :if => Proc.new { |user| user["#{name}country"] == "CA" } composed_of "#{name}address", :class_name => “Address”, :mapping => [ ["#{name}address_one", "address_one"], ["#{name}address_two", "address_two"], ["#{name}city", "city"], ["#{name}state_province", "state_province"], ["#{name}postal_code", "postal_code"] ["#{name}country", "country"] ] end end end ActiveRecord::Base.send :include, Addressable

Rails Code Review PDF

2010-03-01T16:25:00.002+08:00

http://peepcode.com/products/rails-code-review-pdf

Enable or fix logging for HAProxy load balancer

2010-02-26T10:34:00.001+08:00

Enable or fix logging for HAProxy load balancer

On a RedHat/CentOS server, edit the value of SYSLOGD_OPTIONS in /etc/sysconfig/syslog:

SYSLOGD_OPTIONS=”-m 0 -r”

On a Debian/Ubuntu server, edit the value of SYSLOGD in /etc/default/syslogd:

SYSLOGD=”-r”

/etc/syslog.conf:

local0.* /var/log/haproxy.log

restart syslog service to apply changes:

service syslog restart

request host, query paramters, header

2010-02-22T14:55:00.006+08:00

登入登出轉址設計

multi-step

2010-02-21T21:26:00.002+08:00

RoR Multi-step forms

private def get_partial_user_from_session unless @session['partial_user'].nil? @user = @session['partial_user'] else @user = User.new end end def save_partial_user_in_session unless @user.nil? @session['partial_user'] = @user end end # Might be a good addition to AR::Base def valid_for_attributes( model, attributes ) unless model.valid? errors = model.errors our_errors = Array.new errors.each { |attr,error| if attributes.include? attr our_errors << [attr,error] end } errors.clear our_errors.each { |attr,error| errors.add(attr,error) } return false unless errors.empty? end return true end #To ensure the errors are cleared out properly on each request add a before_filter with the following: def clear_stage_errors unless @session['partial_user'].nil? @session['partial_user'].errors.clear end end =begin You can use get_partial_user_from_session and save_partial_user_in_session as before and after filters, respectively, so you only have to reference @user in your multi-step controller. =end #A clean way to arrange the view is to have each step in its own partial, and set a variable such as @current_stage #in your controller, then in your view just do something like: <%= start_form_tag({:action=> "signup"} , { :name => 'signupform' }) %> <%= hidden_field_tag "changeCountry" %> <%= hidden_field_tag "current_stage", "#{@current_stage}"%> <h2>Registration Process</h2> <%= @flash['notice'] %> <%= render_partial "#{@current_stage}" %> <%= end_form_tag %> #Your signup controller action could something similar to this: def signup case @request.method when :post @current_stage = @params['current_stage'] if @current_stage == "stage1" @user.attributes = @params['user'] @current_stage = "stage2" if valid_for_attributes(@user,["login","attribute2"]) end elsif @current_stage == "stage2" @user.attributes = @params['user'] @current_stage = "stage3" if valid_for_attributes(@user,["attribute3","attribute4"]) elsif @current_stage == "stage3" @user.attributes = @params['user'] if @user.save @session[:user] = User.authenticate(@user.login, @params['user']['password']) flash['notice'] = "Signup successful" redirect_to :action => "home" end end when :get @current_stage = "stage1" end end #========================================== =begin Comments on this post bmarini posts on May 19, 2008 at 12:56 I took your partial validation idea and included it in AR Base =end module ActiveRecord module Validations module Partial def valid_for_attributes?( *attr_names ) return validate_for_attributes(attr_names) end def validate_for_attributes( *attr_names ) attr_names.map! {|a| a.to_s } unless valid? our_errors = Array.new errors.each { |attr,error| if attr_names.include? attr our_errors << [attr,error] end } errors.clear our_errors.each { |attr,error| errors.add(attr,error) } return false unless errors.empty? end return true end end end end ActiveRecord::Base.class_eval do include ActiveRecord::Validations::Partial end =begin cgunther posts on Jul 02, 2009 at 11:40 bmarini, I think there is a bug in your code. When I called: =end @order.valid_for_attributes? 'first_name', 'last_name' =begin It always passed validation. The error was the asterisk in front of attr_names on validate_for_attributes. It was being passed an array as the first attribute and when you run map! on it, it was converting the entire array to a single string (first_namelast_name). Here's the code that works for me: =end module ActiveRecord module Validations module Partial def valid_for_attributes?( *attr_names ) return validate_for_attributes(attr_names) end def validate_for_attributes( attr_names ) attr_names.map! {|a| a.to_s } unless valid? our_errors = Array.new errors.each { |attr,error| if attr_names.include? attr our_errors << [attr,error] end } errors.clear our_errors.each { |attr,error| errors.add(attr,error) } return false unless errors.empty? end return true end end end end ActiveRecord::Base.class_eval do include ActiveRecord::Validations::Partial end #The main difference is that if you call validate_for_attributes directly, you have to pass it an array. #Chris Gunther

render outside your controller

2010-02-08T12:01:00.002+08:00

Rails: Calling render() outside your Controllers
Calling Rails Render Partial in a Model or Background Task

# lib/render_anywhere.rb # # Render templates outside of a controller or view. # # Simply mixin this module to your existing class, for example: # # class MyTemplater < ActiveRecord::Base # include RenderAnywhere # # And you can use render() method that works the same as ActionView::Base#render # # obj = MyTemplater.new # obj.html = obj.render :file => '/shared/header' # # module RenderAnywhere class DummyController def logger RAILS_DEFAULT_LOGGER end def headers {} end end def render(options, assigns = {}) viewer = ActionView::Base.new(Rails::Configuration.new.view_path, assigns, DummyController.new) viewer.render options end def template_exists?(path, assigns = {}) viewer = ActionView::Base.new(Rails::Configuration.new.view_path, assigns, DummyController.new) viewer.pick_template_extension(path) rescue false end end

Turning web server configuration

2010-02-07T14:02:00.005+08:00

Setting Static Asset Expires Headers with nginx and Passenger

Nginx

location ~* \.(ico|css|js|gif|jpe?g|png)(\?[0-9]+)?$ {
    expires max;
    break;
}

redirect permanent

2010-02-04T12:33:00.005+08:00

Permanent Redirect with HTTP 301


#Apache
    RewriteCond %{HTTP_HOST}   17\.ooxx\.com [NC]
    RewriteRule ^/(.*)         http://17.ooxx.com.tw/$1 [L,R=permanent]

#Nginx
    if ($host ~* ^17.ooxx\.com) {
      rewrite ^/(.*) http://17.ooxx.com.tw/$1 permanent;
    }

META HTTP-EQUIV="refresh" 實現網頁自動跳轉

2010-02-03T14:26:00.002+08:00

META HTTP-EQUIV="refresh" 實現網頁自動跳轉

rails default environment

2010-02-02T17:09:00.001+08:00

~/.bashrc

export PATH=$PATH:/opt/ruby-enterprise/bin
export RAILS_ENV=production

nginx memo

2010-02-02T07:26:00.007+08:00

Nginx泛域名解析及Rewrite重定向普通頁面及帶參數的頁面
Nginx "how to" - Fast and Secure Web Server
Nginx Location

靜態地址重定向到帶參數的動態地址

rewrite "^(.*)/service/(.*)\.html$" $1/service.php?sid=$2 permanent;

帶參數的動態地址重定向到靜態地址

if ($query_string ~* id=(.*)) {
    set $id $1;
    rewrite "^(.*)/article.asp$" $1/article/$id.htm last;
}

舉例:
abc.domian.com/sort/2 => abc.domian.com/index.php?act=sort&name=abc&id=2


if ($host ~* (.*)\.domain\.com) {
    set $sub_name $1;
    rewrite ^/sort\/(\d+)\/?$ /index.php?act=sort&cid=$sub_name&id=$1 last;
}

Nginx Rewrite Flags
* last 相當於Apache裡的[L]標記，表示完成rewrite
* break 終止匹配, 不再匹配後面的規則
* redirect 返回302臨時重定向
* permanent 返回301永久重定向

Nginx正則表達式匹配
* ~ 為區分大小寫匹配
* ~* 為不區分大小寫匹配
* !~和!~*分別為區分大小寫不匹配及不區分大小寫不匹配

Nginx文件及目錄匹配
* -f和!-f用來判斷是否存在文件
* -d和!-d用來判斷是否存在目錄
* -e和!-e用來判斷是否存在文件或目錄
* -x和!-x用來判斷文件是否可執行

Nginx全局變量
$args
$content_length
$content_type
$document_root
$document_uri
$host
$http_user_agent
$http_cookie
$limit_rate
$request_body_file
$request_method
$remote_addr
$remote_port
$remote_user
$request_filename
$request_uri
$query_string
$scheme
$server_protocol
$server_addr
$server_name
$server_port
$uri

restart nginx

2010-02-01T14:15:00.002+08:00

 
alias startnginx='sudo /opt/nginx/sbin/nginx' 
alias stopnginx='sudo kill `cat /opt/nginx/logs/nginx.pid `' 
alias restartnginx='stopnginx; startnginx'

transcation

2010-02-01T12:12:00.004+08:00

Transaction in Rails
Working with transactions in Rails

ssl apache nginx configuration

2010-01-29T17:28:00.006+08:00

http://articles.slicehost.com/2010/1/11/managing-ssl-certificates-1
http://articles.slicehost.com/2010/1/11/managing-ssl-certificates-2
Nginx SSL 實務
SSL Certificate Installation in Nginx
Configuring HTTPS servers

ssl 設定的file 有三種伺服器憑證, 中繼憑證, RSA key
各種web server 吃的方式不同

Nginx 設定



listen  ip.address:443; #監聽HTTPS, 通常是Port 443
ssl  on;
ssl_certificate  /path/to/server.crt; 
ssl_certificate_key  /path/to/private.key; #這是伺服器用的RSA Key


#server.crt要用發下來的伺服器憑證與中繼憑證合併產生:
cat domain_name.crt ca_bundle.crt  > server.cr


SSLCertificateFile /etc/ssl/apache_ca.crt      #這是伺服器憑證
SSLCertificateKeyFile /etc/ssl/www.goyou.com.tw.key   
SSLCertificateChainFile /etc/ssl/chain.crt    #中繼憑證

nginx , page cache, capistrano

2010-01-28T11:24:00.007+08:00

Segregated page cache storage
Rails page caching vs nginx Restful route 可能會造成有相同的html, like index and create, 所以利用nginx 做一些檢查來避免
nginx rewrite rules with Passenger

if (-f $request_filename) {
  break;
}

# cached pages
#set $cache_extension '';
#if ($request_method = GET) {
#  set $cache_extension '.html';
#}

# the above is a hack because nginx doesn't allow nested or ANDed ifs
#if (-f $request_filename$cache_extension) {
#  rewrite (.*) $1.html break;
#}

# 這個才有用 上面那些都沒用 orz, 用$uri 才有用
if (-f $document_root/cache/$uri/index.html) {
  rewrite (.*) /cache/$1/index.html break;
}

if (-f $document_root/cache/$uri.html) {
  rewrite (.*) /cache/$1.html break;
}


# everything else goes to the mongrel cluster
if (!-f $request_filename) {
  proxy_pass http://mongrels;
  break;
}

#In config/environments/production.rb, tell Rails to put cached pages in the public/cache directory.

config.action_controller.page_cache_directory = File.join(RAILS_ROOT, 'public', 'cache')

#In nginx.conf, set up the precedence for locating static files. First look in public for regular static files. Next look in the cache directory for an exact match for the url. Lastly, look in the cache directory for the url with .html appended. That will let you cache pages for regular URLs with no .html extension as well as ones with extensions like .xml, .atom, .json, etc.

  if (-f $request_filename) { 
    break; 
  }

#  if (-f /cache$request_filename) { 
#    rewrite (.*) /cache$1 break;
#    break; 
#  }

#  if (-f /cache$request_filename.html) { 
#    rewrite (.*) /cache$1.html break;
#    break; 
#  }

#The capistrano recipes have to do a couple things. You need to create the shared/cache directory when setting up the deployment.

after "deploy:setup", "create_page_cache"
task :create_page_cache, :roles => :app do
  run "umask 02 && mkdir -p #{shared_path}/cache"
end


after "deploy:update_code","symlink_shared_dirs"
task :symlink_shared_dirs, :roles => :app, :except => {:no_release => true, :no_symlink => true} do
    run <<-CMD
      cd #{release_path} &&
      ln -nfs #{shared_path}/cache #{release_path}/public/cache
    CMD
end

#When doing a deploy, the standard behavior is to flush the cache, just to be on the safe side. If you want to retain cached pages, as when making a change you know won't affect rendering, tell capistrano not to flush.

# default behavior is to flush page cache on deploy
set :flush_cache, true

# page cache management
task :keep_page_cache do
  set :flush_cache, false
end

after "deploy:cleanup", "flush_page_cache"
task :flush_page_cache, :roles => :app do
  if flush_cache
    run <<-CMD
      rm -rf #{shared_path}/cache/*
    CMD
  end
end

#With the above setup, you can deploy and retain the cache with the following capistrano command:
$ cap keep_page_cache deploy

Moneta, memcache

2010-01-08T16:11:00.002+08:00

Moneta: 提供 key/value stores 的統一介面
moneta github
handcache github

heroku 上你要它卻沒有的gem

2010-01-05T00:14:00.003+08:00

Automatically generate Heroku .gems file

用個rake 幫你生這個file

Changing Your Origin

2009-12-31T16:49:00.004+08:00

Changing Your Origin

目前這樣只到可以pull的地步

但是如果需要push 到不同的remote 端還需要修改 .git/config
需要補上push 的部份

fb comment

2009-12-16T17:40:00.002+08:00

FBML 和 XFBML 不同阿小心 orz

http://wiki.developers.facebook.com/index.php/Fb:comments
http://wiki.developers.facebook.com/index.php/Fb:comments_(XFBML)

write rails plugin memo

2009-12-08T10:59:00.002+08:00

The Basic of Creating Rails Plugins

3 Extending Core Classes
This section will explain how to add a method to String that will be available anywhere in your rails app.

http://guides.rubyonrails.org/plugins.html#extending-core-classes

Paginating with the Fragment Cache

2009-12-03T15:04:00.003+08:00

Paginating with the Fragment Cache

group count

2009-12-03T14:15:00.003+08:00

fbml in iframe canvas by serverfbml

2009-11-29T11:30:00.001+08:00

Fb:serverfbml

Resizable IFrame

2009-11-29T06:41:00.003+08:00

Resizable IFrame
JavaScript Client Library
Note: You must include the <[script]> tag that loads the FeatureLoader in the <[body]> element, not in the <[head]> element, because the FeatureLoader writes body elements directly to the document, and some browsers report an error if this happens when FeatureLoader is in the <[head]> tag.
http://wiki.developers.facebook.com/index.php/Cross_Domain_Communication_Channel

rjs page call

2009-11-22T21:01:00.009+08:00

RJS Page.call
Passing objects from Rails RJS to a javascript function call without quoting the values?
http://api.rubyonrails.org/classes/ActionView/Helpers/PrototypeHelper/JavaScriptGenerator/GeneratorMethods.html

 
#有些時候page.call paramter work 不是很正常
page.call "get_details", "info-id", "message","{phone:5487895, mobile:9888565875}"
page.call("buildYUITreeView", "project_tree", @current_project.get_directory_contents(@current_project.local_path, 0))
#可以用這樣的方式去取代
page << "get_details('info-id','message','{phone:5487895, mobile:9888565875}')"
page << "buildUYITreeView('project_tree', #{@current_project.get_directory_contents(@current_project.local_path, 0))})"


      respond_to do |format|
        format.js {render(:update) { |page| page << 'alert("Wrong Nick");'}}
      end


  update_page do |page|
    page.insert_html :bottom, 'list', "#{@item.name}
"
    page.visual_effect :highlight, 'list'
    page.hide 'status-indicator', 'cancel-link'
  end

Problem updating to Rubygems 1.3.5

2009-11-17T12:55:00.002+08:00

更新又失敗了

直接用source 裝吧

http://railsforum.com/viewtopic.php?id=34044 <= Problem
http://docs.rubygems.org/read/chapter/3 <= install rubygem

facebook iframe use fbml

2009-11-16T10:03:00.003+08:00

http://wiki.developers.facebook.com/index.php/Fb_force_mode

除了用xfbml之外, 還有這招可以用

For example, if you were using an iframe application, and wanted one page to be rendered as FBML, you could append ?fb_force_mode=fbml to the address, which will cause it to render as FBML. This can be particularly useful when using fb:request-form with iframe applications.

If your application is an iframe application and you wish to use FBML, you will need to specify the full address, including http://apps.facebook.com.

include vs joins

2009-11-15T20:06:00.003+08:00

http://railscasts.com/episodes/181-include-vs-joins

User.all(:joins => :comments, :select => "users.*, count(comments.id) as comments_count", :group => "users.id") g = Group.first Comment.all(:joins => {:user => :memberships}, :conditions => { :memberships => { :group_id => g.id } }) # models/comment.rb class Comment < ActiveRecord::Base belongs_to :user end # models/user.rb class User < ActiveRecord::Base has_many :memberships has_many :groups, :through => :memberships has_many :comments end # models/membership.rb class Membership < ActiveRecord::Base belongs_to :user belongs_to :group end # models/group.rb class Group < ActiveRecord::Base has_many :memberships has_many :users, :through => :memberships #rails does not support nested association def comments Comment.scoped(:joins => {:user => :memberships}, :conditions => { :memberships => { :group_id => id } }) end end

dynamic asset_host

2009-11-13T14:56:00.002+08:00

google seo memo

2009-11-13T09:50:00.008+08:00

Google SEO Starter Guide
github meta tag plugin

1. title
<[title]> 標記應該放在 HTML 文件的 <[head]> 標記區段中。
理想情況下,您應該為網站的每一個網頁建立獨特的網頁標題

您的文件出現在搜尋結果網頁中,標題標記的內容通常會出現在搜尋結果的第一行

2. meta desc
Google 網站管理員工具」提供了好用的內容分析工具,可以指出太短、太長或過分重複的描述中繼標記使用簡短但描述明確的標題

improve-snippets-with-meta-description

3. 有意義的url
http://www.google.com/support/webmasters/bin/answer.py?answer=76329
在網址中使用文字
建立簡單的目錄架構
為同一文件提供同一版本的網址

如果您確實發現有使用者透過不同的網址來瀏覽同樣的內容,您可以設定 301 重新導向,將不喜歡的網址重新導向到您所期望使用的網址

請避免:
無論從子域還是根目錄 (例如「domain.com/page.htm」和「sub.domain.com/page.htm」) 都可以瀏覽到相同的內容
在您的內部連結架構中混合使用 www. 和非 www. 版本的網址
在網址中使用奇怪的大寫字母 (大部分使用者喜歡小寫的網址,並且小寫也便於使用者記憶)

4. 讓您的網站更易於瀏覽

您也可以使用 Google 的「網站管理員工具」提交 XML Sitemap (字母大寫),讓 Google 更容易發現您網站上的網頁。使用 Sitemap 還有一個好處 (雖然我們無法做出保證),就是您可以使用它來告知Google 哪個版本的網址是您偏好的標準網址 (例如:http://brandonsbaseballcards.com/ 或http://www.brandonsbaseballcards.com/;請瀏覽更多關於什麼是偏好網域的詳情)。Google 協助建立了開放原始碼的 Sitemap 產生器指令碼,以幫助您為自己的網站建立 Sitemap 檔案。如需有關Sitemap 的進一步資訊,請前往網站管理員說明中心,瀏覽實用的 Sitemap 檔案指南。

5. 網站導覽實作典範

建立自然流暢的層級架構
請避免:
建立複雜的導覽連結網。例如,將網站上都每個網頁都連結至所有其他網頁
過度細分內容 (使用者必須要按二十次才能找到位於深層的內容)

導覽中盡量使用文字連結
請避免:
完全依靠下拉功能表、圖片或動畫來建立導覽 (雖然大多數搜尋引擎能夠發現
網站的此類連結,但如果讓使用者能透過正常文字連結到達網站上的所有網頁,
將可以提高網站的可用性;請瀏覽更多關於 Google 如何處理非文字檔案的
詳情)

使用「麵包屑」導覽 — 麵包屑導覽是指在網頁頂端或底部放置一排內部連結,讓訪客可以
快速回到上一個網頁或根網頁。大多數的麵包屑導覽通常會將最具概括性的網頁 (通常是根網
頁) 放在最左邊的第一位,越靠近右邊,列出的網頁包含的內容更越具體。

在您的網站上放置 HTML Sitemap 網頁,並使用 XML Sitemap 檔案 — 一個包含您網站
上所有網頁或最重要網頁 (如果您有成百上千個網頁) 的簡單 Sitemap 網頁,將會非常有用。

請避免:
在 HTML Sitemap 網頁中放置無效連結,使得網頁沒什麼用處
建立的 HTML Sitemap 僅簡單列出網頁,而沒有進行整理,例如依主題整理

請避免:
讓搜尋引擎建立 404 網頁的索引 (請務必將網站伺服器設定為當使用者要求的
網頁不存在時,能傳回 404 HTTP 狀態碼)
只提供類似於「Not found」、「404」等模糊的訊息,或者甚至連 404 網頁都沒有
404 網頁的設計與您網站的其他網頁不一致

6. 撰寫更佳的錨定文字
這個錨定文字有時會告知使用者和 Google 有關您要連結之網頁的部分內容。您網頁上的連結可能是
內部連結 (即指向您網站上其他網頁的連結),也可能是外部連結 (即指向其他網站之內容的連結)。
無論是哪種情況,您的錨定文字寫得越詳細,使用者就越容易瀏覽,Google 也越容易瞭解您所連結的
網頁內容。

請避免:
撰寫一般的錨定文字,比如「網頁」、「文章」或「按一下此處」
使用偏離主題或與要連結之網頁內容無關的文字
在多數情況下,使用網頁網址作為錨定文字 (即使某些情況可以這麼做,例如

7. 適當使用標題標記
標題標記 (請不要將其和 <[head]> HTML 標記或 HTTP 標頭混淆) 用於為使用者呈現網頁的結構。標
題標記有六種不同大小,從 <[h1]> 到 <[h6]>,其重要性依次降低。

請避免:
在標題標記中放置對定義網頁結構沒有任何幫助的文字
在適合使用其他標記 (例如 <[em]> 和 <[strong]>) 的地方,不要使用標題標記
隨意調整標題標記的大小

8. 最佳化圖片的使用
圖片似乎是比較簡單的網站元件,但您可以對圖片的使用進行最佳化。所有圖片都有不同的檔案名稱和
「alt」屬性,您可善加利用這兩個特點。

請避免:
儘可能使用像「image1.jpg」、「pic.gif」、「1.jpg」這樣的通用檔案名稱 (有
些網站的圖片超過數千張,因此可能會為圖片自動命名)
撰寫過長的檔案名稱
在替代文字中堆砌關鍵字,或者複製並貼上完整的句子

將圖片儲存在專用的目錄中 — 考慮將您的圖片合併到一個單獨的目錄中 (例如
brandonsbaseballcards.com/images/),而不是將圖片散佈在整個網域的很多目錄和子目錄下。
這樣可以簡化圖片的連結路徑。

9. 利用 robots.txt
「robots.txt」檔案可告知搜尋引擎是否可以存取您網站的某些部分,進而對這些部分進行檢索。此檔案
必須要命名為「robots.txt」,並放置在您網站的根目錄中。

http://baseball.com/robots.txt

user-agent: *
Disallow: /images/
Disallow: /search
所有符合條件的搜尋引擎漫遊器 (標有萬用字元符號 *) 都不會存取和檢索 /images/ 下的內容,
或者任何以 /search 作為路徑開頭的網址

「Google 網站管理員工具」中有一個很好用的
robots.txt 產生器,可協助您建立此檔案。請注意,如果您的網站使用了子網域,且您不希望搜尋引擎檢索特定子網域中的某些網頁,則您必須為該子網域建立一個單獨的 robots.txt 檔案。如需更多有關
robots.txt 詳情,我們建議您參閱有關使用 robots.txt 檔案的網站管理員說明中心指南。

對敏感的內容使用更為安全的方法 — 您或許對使用 robots.txt 來封鎖敏感或保密的材料感
覺不是特別放心。其中一個原因是,如果網際網路上碰巧存在連至您封鎖的網址的連結 (如參照記錄),則搜尋引擎仍然可以參照該網址 (只是顯示網址,而不顯示標題或片段內容)。此外,不遵守漫遊器排除標準的一些非符合條件的或惡意搜尋引擎可能會違背您的 robots.txt 指示。
最後,好奇的使用者可能會查看您 robots.txt 檔案中的目錄或子目錄,並猜中您不願被看到
的內容的網址。對內容加密或使用 .htaccess 對內容進行密碼保護是更安全的選擇。

10. 瞭解連結的 rel="nofollow"

將某個連結的「rel」屬性值設定為「nofollow」便會告知 Google 不應隨著您網站上的某些連結連至
他處,也不應將您網頁的信譽情況傳給連至的網頁。不隨著某個連結連至他處的方法是,在連結的錨定
標記中新增 rel="nofollow"。

<[a href='http://www.shadyseo.com/' rel='nofollow'>Comment spammer<[/a]>

最後,如果您有意不隨著網頁中的任何連結連至他處,則可以在您的 robots 中繼標記中使用
「nofollow」,將這個 robots 中繼標記放入該網頁 HTML 的 <[head]> 標記中。網站管理員中心網誌
提供了一篇有關使用 robots 中繼標記的很有益的文章。這種方法的寫法是 <[meta name="robots"
content="nofollow"]>。

建立並提交 Sitemap

simple memo, initializer run

2009-10-28T07:23:00.001+08:00

Class Rails::Initializer

Symmetric Encryption vs Asymmetric Encryption

2009-10-26T22:16:00.001+08:00

http://support.oss.org.tw/wiki/index.php/

Symmetric Encryption – 對稱式加密簡介
其特色在於加解密所使用的金鑰(key)是相同的!
●兩方要進行秘密訊息的傳送之前，必須協議出一個共同的，用來加解密的金鑰(key)以及所使用的演算法；如此訊息一來一往之間，才可以被正確的加解密。
●當然這樣的方式會衍生出一些問題，因此才會有 Asymmetric Encryption(非對稱式加密) 的產生，來改善一些 Symmetric Encryption 的缺點；然而 Symmetric Encryption 在實際的應用上有其實用性，因此目前還是持續不斷的被使用當中

在加解密運作的機制中，有兩大重要部分，除了金鑰(key)之外，另外一個即為加解密所使用的演算法(algorithm)。
在實際應用上，金鑰(key)是一個檔案，內容為一群無意義的英文與數字的集合，長度範圍有可能介於 64~1024 bits (甚至更大) 之間，妥善由通訊雙方秘密保管好。
而演算法(algorithm)則是透明公開的，隨時可以從網路或是其他地方取得演算法的相關使用方法與規則。

Asymmetric Encryption (非對稱式加密) 即是為了改良 Symmetric Encryption(對稱式加密) 的缺點而產生的。
在對稱式加密中，通訊雙方往來的訊息是由同一把金鑰進行加密；假設 A 與 B 通訊，兩個人必須有一把相同的金鑰；而若是 A 也要與 C 通訊，則 A 與 C 則必須擁有另外一把不同的金鑰；否則若是都使用相同金鑰，C 就可以解密出 A 要給 B 的訊息，相對的，B 也可以解密出 A 要給 C 的訊息，如此一來資訊在傳送就不再安全!
除此之外，還要防範金鑰被竊取的問題，只要通訊雙方任一方把金鑰洩露出去，就破壞了原本建立的安全機制了。
因此，Asymmetric Encryption(非對稱式加密) 使用了一對金鑰(key pair)的方式解決了這個問題

在 Asymmetric Encryption 的架構中，要通訊的雙方都各持有一對金鑰，分別是私鑰(private key)以及公鑰(public key)。
private key 是要妥善且由自己秘密保管的，而 public key 則是可以公開出去。
假設使用者 A 有一對金鑰，若是 B 要與 A 進行通訊，則 B 必須使用 A 所提供的 public key 進行加密，再將加密的內容傳送給 A，接著 A 可以用自己的 private key 進行解密。同樣的，A 要是要傳訊息給 B，則是要使用 B 所提供的 public key 進行加密，而 B 則可以用自己的 private key 進行解密。
有趣的是，雖然訊息是由 public key 所加密，但是卻無法利用 public key 將原本的訊息還原回來，這就是非對稱式加密的精華所在，也是目前非常受到歡迎的原因。而這一來一往之間，所使用的演算法，即為 RSA 演算法。

如此看來，其實 RSA 的加解密過程是很簡單的，因此重點就是在於金鑰的產生，目前已經被證明長度 1024 bits 不夠安全，因此建議使用長度為 2048 bits 的金鑰作為加解密之用，來提升重要資訊傳輸的安全性。
最後，雖然非對稱式加密解決了金鑰交換的問題，但是卻衍生出加解密效率不彰的問題，因為相較於 DES，RSA 的速度只有其百分之一不到

Asymmetric + Symmetric

真的沒有更好的 solution 嗎? 當然是有的...只要巧妙的結合兩者的優點即可啦!! 其中的原理很簡單，假設 A 要傳訊息給 B，就會發生大概類似以下流程：
(1) A 透過對稱式演算法，產生出一把對稱式加密用的金鑰
(注意：這把金鑰只用在這一次的傳輸)
(2) 接著 A 使用 B 所提供的 public key，將這把金鑰加密，
並將加密後的內容傳給 B
(3) B 接收到後，使用自己的 private key 解密，取得這把
一次性金鑰
(4) 之後雙方訊息的往來，都使用對稱式加密
如此一來，就不僅解決了金鑰交換的問題，也解決了非對稱式加解密效率不彰的問題。
當然，這樣的 solution 其實還不算最安全，因此才會有 Digital Signature(數位簽章) 的誕生

facebook 發post ( story ) 到 wall

2009-10-26T15:35:00.005+08:00

http://wiki.developers.facebook.com/index.php/Feed_forms
http://wiki.developers.facebook.com/index.php/FB.Connect.streamPublish
http://wiki.developers.facebook.com/index.php/Attachment_%28Streams%29
http://wiki.developers.facebook.com/index.php/Stream.publish

http://wiki.developers.facebook.com/index.php/XFBML
http://blog.yangtheman.com/2009/08/23/how-to-integrate-facebook-connect-with-a-rails-app/

這邊用的是iframe canvas下的 push 方式, 基本上是跟 facebook connect 相同的

需要include XFBML 和 facebook connect 的 js

Authorizing Applications, share button

2009-10-21T17:42:00.002+08:00

Authorizing_Applications
share button

Once a user has authorized your application, you can utilize the following URLs, which you specify in your application's settings in the Developer application:

* Post-Authorize Callback URL: Facebook pings this URL when a user authorizes your application for the first time. You can also call users.isAppUser to determine if the user has authorized your application.
* Post-Authorize Redirect URL: You can redirect a user to this URL after the user authorizes your application for the first time. You can use this URL only if the user authorizes your application through login.php and not the login dialog.
* Post-Remove Callback URL: Facebook pings the URL when a user removes your application.

For FBML canvas page applications, the parameters are sent as POST parameter. For iframe applications, the parameters are sent as GET parameters, unless you are preloading FQL using the fb_iframe_post option, in which case the parameters are sent as POST parameters.

Choosing between an FBML or IFrame Application(2)

2009-10-21T14:42:00.002+08:00

Now, with XFBML, in addition to being able to embed things like fb:name and fb:profile-pic directly into your HTML, you can render any FBML tag by using server-side FBML. If you wrap your FBML inside fb:serverfbml tags, as in:

...then this opens an IFrame to Facebook on the page being served from your domain, and Facebook will render the FBML in there.

However, a fair amount of overhead is involved in opening the IFrame, and your CSS won't propagate into the FBML IFrame, so you won't want to put too many blocks of server-side FBML on a page. But if you need one or two snippets of FBML to make your application richer, or you want a large chunk of your page to use FBML, this makes that possible and pretty easy.

Preload FQL

Preload FQL lets you do these sorts of queries on both FBML and IFrame canvas pages, though it works differently for each. In general, you specify a few regular expressions that map to lists of FQL queries. If the page being requested matches any of the regular expressions, the corresponding FQL queries will be executed by Facebook when the user's browser sends the request to Facebook.

For FBML applications, the results get sent along to your application's servers when Facebook requests the FBML from you. Most of the time, this makes calls to the Facebook API unnecessary, even when you need fairly complicated data from Facebook to generate the page.

This is what the flow would look like for an FBML canvas page using preload FQL

FBML Canvas Page Using Preload FQL

Preloading FQL works differently with IFrames. In order for Facebook to send data to your server along with the request for the IFrame, it has to encode the data in the URL being requested. Instead of sending the FQL result set to your server, the Facebook server sends the FQL result data down to the user's browser, attached to the outer frame that contains the Facebook chrome on the canvas. You can choose whether you want to have a lightweight redirect occur, which encodes the FQL results in the request made for your IFrame page. Or, if you only want to access that data on the client side, you can use the PreloadFQL_get method from the JavaScript client library and rewrite parts of the page on the fly using the data after it's initially rendered.

IFrame Canvas Page using Preload FQL

Note that the preload FQL will only work on the first page that loads in your IFrame. If you point your links to apps.facebook.com URLs using target="_top" instead of just linking to different pages within the frame, you could use preload FQL on every page, but this would make all your pages load slowly

Choosing between an FBML or IFrame Application(1)

2009-10-21T11:16:00.004+08:00

Choosing between an FBML or IFrame Application

Traditional IFrame Canvas Page

FBML Canvas Page

XFBML as part of Facebook Connect as a way to quickly get social content onto any Web page, and since IFrames are just Web pages, XFBML can speed those up as well.

Before XFBML, IFrame applications always had to make API calls to render social content like user names and profile pictures, and those API calls required another round trip communication between your server and Facebook before sending back content to the user's browser

with XFBML, you can embed various FBML tags like fb:name and fb:profile-pic directly into the HTML that your application sends to the user's browser. Then you simply include some Facebook-specific JavaScript, and that code gets executed and scans the DOM for those tags. The JavaScript then determines all the data needed to render that content and batches it up into one API call from the user's browser to Facebook

The rest of the page that isn't social content can render to the user before the API call completes. And in XFBML, we cache data on the browser so that in many cases, it isn't even necessary to make any API call to Facebook at all.

IFrame Canvas Page Using XFBML - First Page Load by a User

IFrame Canvas Page Using XFBML - Subsequent Page Loads by a User

找該加index 的地方

2009-10-19T13:57:00.002+08:00

rails_indexes

check index exist

2009-10-19T13:50:00.002+08:00

add_index 之前檢查一下

mustache 把view logic 的部份再拆出來

2009-10-18T21:28:00.001+08:00

就是要讓view 更乾淨把logic 的部份再拆出來
mustache

Ruby on Rails Code Quality Checklist

2009-10-18T16:45:00.002+08:00

Ruby on Rails Code Quality Checklist

1. Each controller action only calls one model method other than an initial find or new.
(Make custom .new or .update methods in the model with all necessary). ...
就是盡量把邏輯擺到model 裡, 唯一的例外就是在決定要render view or redirect的時候

2. Only one or two instance variables are shared between each controller and view. ...
保持一兩個instance variable 在controller 和 view 就好
這樣可以讓所有相關連的只有在需要的時候在被call 到, 而且還可以做instance-variable cache in one place
例如不要在controller 裡用到 @post and @related_posts 兩個instance variable, 而是create a method 給 @post, 這樣你就可以在 view 裡面直接用 @post.related_posts

3. All model and variable names are both immediately obvious (to a new developer) and as short as possible without using abbreviations. ...
取個好名字

4. All custom "finds" accessed from more than one place in the code use named_scope instead of a custom method. ...
有關find 什麼東西的, 都用named_scope 來做

5. A .find or .find_by_ is never called in a view or view helper. ...
別直接在view , find or find_by anything, 至少用一下namde_scope or custom methods to do that

6. There is zero custom code that duplicates functionality of a built-in function in rails. ...
7. Code has been aggressively DRYed during development. ...
8. All functionality used in two or more models has been turned into a library/module. ...
9. All logic duplicated between two or more apps has been turned into a gemified plugin. ...

10. STI is not used anywhere ...
別用STI, 用module 來代替, 如果你用STI 你會需要至少bind 兩個model, 這樣你很難回頭
data migration 你會死
但是polymorphic association 是鼓勵的

11. Every design choice should yield the most simplistic design possible for the need of users at the current time.
No guesses for future functionality were designed into the application. ...
對於現在的情況做最簡單的設計, 不要猜測未來的情況, 你可能會猜錯

12. Close to full test coverage exists at the highest level of the application: on and between controller actions. Coverage is highest for code used by the most number of end users. ...

先從user 最常用的開始測起
13. All tests pass before code is merged into a shared repository. ...

merge 前要測過
14. Every fixed defect on a deployed product has tests added to prevent regression. ...
替解掉的defeat 加上測試

15. Every plugin installed has been code reviewed. ...
檢查一下你的plugin code

Install any HTML theme/template into your Rails app

2009-10-18T12:53:00.003+08:00

Install any HTML theme/template into your Rails app
install_theme
open source web design

幫你用來快速套template 的

[Scale] Scale Frontend 應該注意的五件事

2009-10-17T07:27:00.002+08:00

[Scale] Scale Frontend 應該注意的五件事
Rails in the Wild: 5 Client-Side Performance Observations

1. It’s easy to forget to compress your JavaScript and CSS

要記得 :cache => true
要記得壓 js 和 css

2. Watch out for slow third party services

都是慢在第三方
google ads, analytics 也會托慢, 請用 postload_google_ads

3. Using multiple image hosts doesn’t always mean higher performance

拆那麼多台未必會比較快

4. S3 is NOT a Webserver!

S3 是 storage ，不是 web server。所以不要一股腦的把東西往上丟，要注意有沒有敏感資訊，而且 s3p 是沒有幫忙做 gzip 的。

5. Most performance variability is NOT attributable to page factors

速度慢通常是慢在後端..

clearance 的 generator

2009-10-16T16:46:00.003+08:00

clearance
Class Rails::Generator::Commands::Create

#這邊是需要的library
 require File.expand_path(File.dirname(__FILE__) + "/lib/insert_commands.rb")
 require File.expand_path(File.dirname(__FILE__) + "/lib/rake_commands.rb")
 require 'factory_girl'
 
 class ClearanceGenerator < Rails::Generator::Base
 
 def manifest
 record do |m|
 # 原來可以這樣insert GOOD
 m.insert_into "app/controllers/application_controller.rb",
 "include Clearance::Authentication"
 
 user_model = "app/models/user.rb"
 if File.exists?(user_model)
 m.insert_into user_model, "include Clearance::User"
 else
 #原來也可以生目錄
 m.directory File.join("app", "models")
 m.file "user.rb", user_model
 end
 
 m.directory File.join("test", "factories")
 m.file "factories.rb", "test/factories/clearance.rb"
 
 #還可以選擇用哪個file migrate, 叫啥名字
 m.migration_template "migrations/#{migration_name}.rb",
 'db/migrate',
 :migration_file_name => "clearance_#{migration_name}"
 
 m.readme "README"
 end
 private
 
 def migration_name
 #可以check table 在不在
 if ActiveRecord::Base.connection.table_exists?(:users)
 'update_users'
 else
 'create_users'
 end
 end
 
 end
 
 #--------------------------------------------------
 Rails::Generator::Commands::Create.class_eval do
 def insert_into(file, line)
 logger.insert "#{line} into #{file}"
 unless options[:pretend] || file_contains?(file, line)
 gsub_file file, /^(class|module) .+$/ do |match|
 "#{match}\n #{line}"
 end
 end
 end
 end

#/clearance/templates/migrations/create_users.rb
 class ClearanceCreateUsers < ActiveRecord::Migration
 def self.up
 create_table(:users) do |t|
 t.string :email
 t.string :encrypted_password, :limit => 128
 t.string :salt, :limit => 128
 t.string :confirmation_token, :limit => 128
 t.string :remember_token, :limit => 128
 t.boolean :email_confirmed, :default => false, :null => false
 t.timestamps
 end 
 
 add_index :users, [:id, :confirmation_token]
 add_index :users, :email
 add_index :users, :remember_token
 end
 
 def self.down
 drop_table :users
 end
 end
 
 
 #-------------------------------------
 #/clearance/templates/migrations/update_users.rb
 class ClearanceUpdateUsers < ActiveRecord::Migration
 def self.up
 <%
 # ActiveRecord::Base.connection.columns(:users).collect { |each| each.name } = User.columns.map { |each| each.name }
 existing_columns = ActiveRecord::Base.connection.columns(:users).collect { |each| each.name }
 columns = [
 [:email, 't.string :email'],
 [:encrypted_password, 't.string :encrypted_password, :limit => 128'],
 [:salt, 't.string :salt, :limit => 128'],
 [:confirmation_token, 't.string :confirmation_token, :limit => 128'],
 [:remember_token, 't.string :remember_token, :limit => 128'],
 [:email_confirmed, 't.boolean :email_confirmed, :default => false, :null => false']
 ].delete_if {|c| existing_columns.include?(c.first.to_s)}
 -%> 
 change_table(:users) do |t|
 <% columns.each do |c| -%>
 <%= c.last %>
 <% end -%>
 end
 
 <%
 #連有哪些index 也可以看
 existing_indexes = ActiveRecord::Base.connection.indexes(:users)
 index_names = existing_indexes.collect { |each| each.name }
 new_indexes = [
 [:index_users_on_id_and_confirmation_token, 'add_index :users, [:id, :confirmation_token]'],
 [:index_users_on_email, 'add_index :users, :email'],
 [:index_users_on_remember_token, 'add_index :users, :remember_token']
 ].delete_if { |each| index_names.include?(each.first.to_s) }
 -%>
 <% new_indexes.each do |each| -%>
 <%= each.last %>
 <% end -%>
 end
 
 def self.down
 change_table(:users) do |t|
 <% unless columns.empty? -%>
 t.remove <%= columns.collect { |each| ":#{each.first}" }.join(',') %>
 <% end -%>
 end
 end
 end

JavaScript 中的 document.createDocumentFragment

2009-10-16T05:50:00.001+08:00

JavaScript 中的 document.createDocumentFragment

在這段程式碼中，使用了 document.createDocumentFragment() 這個函式產生一個 document fragment，你可以把它想作是一個處理 DOM element 的 buffer，把欲生成的 DOM element 先加入到這個 fragment 中，最後再一次加到頁面的 DOM 結構中，這樣的作法比起在迴圈中一直 appendChild 來得快上許多，當然更重要的是，問題也被解決了 :)

ruby binary code

2009-10-06T17:46:00.001+08:00

有時候想要return 一些binary code 東西要怎樣帶勒

console tips

2009-10-05T20:45:00.002+08:00

Hirb - Irb On The Good Stuff
可以看到sql 結果的

可以看到sql 指令的

has_many , time now, assocation

2009-10-05T20:13:00.002+08:00

Do you know when your code runs?
有時候你時候你會發現你在你下的conditions 有關於時間的, 跑起來有點怪怪的

在development 沒問題, 在production 卻不正常

仔細看會發現時間統統都是static 的了, 因為production 並不會每次都去reload class

這時候只要換個寫法

跨browser 播音樂

2009-10-02T17:22:00.001+08:00

http://www.htmlcodetutorial.com/embeddedobjects/_EMBED.html

Facebook app memo

2009-10-01T09:03:00.004+08:00

Facebook development: choosing FBML or iframe as your application type
http://apps.new.facebook.com/facebooker_tutorial/

1. Set up New application
http://www.facebook.com/developers/

2. remember your api key and serect key

3. Canvas/畫布 setting

api key, serect key

they let our application verify that requests are coming from Facebook.

Facebook sends us the ID of the current user and their whole list of friends on
every request. That makes our life quite a bit easier. It also can cause
some security problems.

All requests come from Facebook. To make sure this is the case, we can
verify the signature that is sent by Facebook on every request. A digital
signature is a way to use cryptography to verify that something actually
came from the person who it appears to be from.4 Facebook sends a
number of parameters that start with fb_sig. All these parameters are
used in the signature validation.

When Facebook sends our applications a request, it builds a string
that includes all the fb_sig parameters in alphabetical order. It then
adds our secret key to the end of that string and calculates the MD5 sum.

When Facebooker receives a request, it goes through the
same steps to recalculate the signature. If the value that Facebooker
calculates matches the one in our request, it proves that the request
came from somebody who knows our secret key.

Rails included a feature to stop cross-site forgery
attacks. Unfortunately, this feature doesn’t play well with Facebook.
We’ll need to disable it by editing environment.rb and setting allow_forgery_
protection to false,

Session Management

2009-09-29T14:12:00.003+08:00

When a new session is created, Rails automatically sends a cookie to the browser containing the session id

The data structure takes the form of a hash, identified by a unique session id, a 32-character string of random hex number

Disabling Sessions for Robots

Selectively Enabling Sessions

The Controversial CookieStore

Timing Out and Session Life Cycle
Session Timeout Plugin for Rails

Cookies

Heroku memo

2009-09-25T06:31:00.009+08:00

Deploying Ruby Web Applications to Heroku
custom domain
學習 HeroKu 的架構設計
generate gem file by rake

亂看 redmine code memo

2009-09-23T21:15:00.001+08:00

A Month in Rails

2009-09-22T18:04:00.002+08:00

A Month in Rails

Master-slave
Why I am not using Masochism for my master-slave setups and why monkey-patching isn’t the only solution

Password security

Securely store passwords with bcrypt-ruby; now compatible with JRuby and Ruby 1.9

A rails plugin to store a collection of boolean attributes in a single ActiveRecord column as a bit field.
把boolean 欄位用一個integer column 取代
flag_shih_tzu

security model
acts_as_lockbox for your Rails Models

Observational: Better Observers for ActiveRecord

2009-09-22T17:17:00.002+08:00

Observational: Better Observers for ActiveRecord
一個比較好的observer
1. 老地方, 可是寄信基本上這應該不干 User 的事, 所以把它搬走

2. 把它搬到 observer 裡, 可是如果很多地方都要寄信, 就很麻煩, 要多一堆file

3. 所以就搬到寄信的地方然後由它observe 看起來合情合理

cookie, session and request object

2009-09-22T15:32:00.000+08:00

* Cookie物件

Cookie物件會藉由瀏覽器所提供Cookie功能,將資訊記錄在用戶端電腦裡面,也就是利用Cookie物件來紀錄判斷某個使用者是否曾經進入本網站,當瀏覽者離線,Cookie物件資料紀錄仍然存在用戶端電腦.(當瀏覽器停用cookie設定,此功能就會失效)

Session物件:紀錄Session中的各種描述資訊與邏輯關係,和Cookie不同的是Session可以儲存任意的物件.
Session處理過程:
當伺服器皆收用戶發送的請求後,ROR就會尋找一用戶Session ID,如果沒有該用戶Session ID,會立即建立一個Session,並且分配Session ID,同時同Cookie形式將Session ID保存到用戶瀏覽器上面.之後ROR會根據Session ID來找到保存在伺服器端的Session資料,並且利用Session物件來對Session做各種操作.

* request物件:應用於使用者各種請求,它允許開發者透過某些方法來請求資訊.

常用方法:
1.delete? (用於確定是否為一個刪除操作要求)
2.get? (用於確定是否為一個GET的請求)
3.post? (用於確定是否為一個POST請求)
4.host (用於取得使用者主機的IP位置)
5.protocol(用於確定請求的協議類型)
6.env (用於取得環境變數的資訊)

cron job 跑rake

2009-09-22T11:10:00.001+08:00

How to Schedule a Ruby on Rails Rake Task Via Cron
*/5 * * * * cd /var/www/apps/rails_app/ && /usr/local/bin/rake RAILS_ENV=production rake_task:goes_here

注意它是用 /usr/local/bin/rake

git memo

2009-09-15T05:57:00.004+08:00

Git 版本控制系統 (1)
Git 版本控制系統(2) 開 branch 分支和操作遠端 repo.
Git 原始碼管理
使用Git與Github管理軟體開發專案

git add . 加入所有檔案，包括所有還沒有被追蹤(untracked)的檔案
git add -i 進入互動模式，你甚至可以只 Add 檔案裡面其中的一段程式碼到 staging area 去(稱作patch)
git add -u 只加更新的檔案，不加入還沒有追蹤的檔案 (跟 git commit -a 涵蓋的範圍相同)

git commit -m "blah" 如果沒加 -m 的話, 會開編輯器輸入 commit log (可以在.gitconfig中設定編輯器)
git commit -a -m "foobar" 全部修改的檔案都 add 後 commit 出去 (不包括 untracked 的新檔案)
git commit -v 會開編輯器加上 diff 註解

git rm foobar 刪除
git mv old_file new_file 改檔名

git diff 是比較 working tree 跟 staging area
git diff --cached 是比較 staging area 跟本來的 repo.
git diff HEAD 是比較 working tree 跟本來的 repo.

git reset HEAD filename 會從 staging area 狀態回到 unstaging 或 untracked (檔案內容並不會改變)
git checkout filename 會從 unstaging 狀態回到最初 repo. 的檔案(檔案內容變回修改前)

git branch 建立本地 local branch
git branch -m 改名字 (如果有同名會失敗，改用 -M 可以強制覆蓋)
git branch 列出目前有那些 branch 以及目前在那個 branch
git checkout 切換 branch (注意到如果你有檔案修改了卻還沒 commit，會不能切換 branch，解法稍後會談)
git checkout -b () 本地建立 branch 並立即 checkout 切換過去
git branch -d 刪除 local branch

git merge 合併另一個 branch，若沒有 conflict 衝突會直接 commit。若需要解決衝突則會再多一個 commit。
git merge --squash 將另一個 branch 的 commit 合併為一筆，特別適合需要做實驗的 fixes bug 或 new feature，最後只留結果。合併完不會幫你先 commit。
git cherry-pick 321d76f 只合併特定其中一個 commit。如果要合併多個，可以加上 -n 指令就不會先幫你 commit，這樣可以多 pick幾個要合併的 commit，最後再 git commit 即可。

git push 預設的遠端是 origin，並且會將所有有和 remote 有對應的 local branch 都 push 上去。如果要把新的 local branch push 上去，需要下 git push origin 指令。

如果今天tom的test repo有了新的變更，告訴billy，billy要將變更merge到自己的repo中，可以在本地端輸入

git pull git://github.com/tom/test.git

pull這個指令其實涵蓋了fetch(將變更複製回來)以及merge。
因此經過merge後，tom的變更就加入到billy的repo囉！

另外版本控制系統的branch功能也很有意思，若您的程式碼同時要修改bug，又要加入新功能，可以fork出一個branch，一個專門修bug，一個專門加入新功能，等到穩定後再來merge

git branch bug_fix #建立branch，名為bug_fix
git checkout bug_fix #切換到bug_fix這個branch
git checkout master #換為主要的repo
git merge bug_fix #把bug_fix這個branch和現在的branch合併

若有branch在remote，想要查看並checkout出來

git branch -r #查看遠端branch
git checkout -b bug_fix_local bug_fix_remote #把本機端切換為遠端的bug_fix_remote branch，並命名為bug_fix_local

還有其他可以觀看repo狀態的工具

git log #可以查看每次commit的改變
git diff #可以查看最近一次改變的內容，加上參數可以看其他的改變，並互相比較
git show #可以看某次的變更

如何設計有效的佈局？

2009-09-14T21:17:00.001+08:00

如何設計有效的佈局？

將任務相關的重要信息要直接表現在控件上。用戶更傾向於關注交互控件上的標籤，而不是輔助型的靜態文本。

* 以8px為橫向柵格單位，頁面所有元素寬度都可以是2的倍數，包括圖片和版塊寬度，這樣可以在一定程度上加快頁面（特別是對於J-PEG圖片）的渲染速度（基於計算機內部二進制的運算機制）。其在擴展和兼容性上也有一定優勢。

* 在阿里巴巴中文站中，佈局間距的最小單位為8px，佈局區塊採用32px（8px*4）和24（8px*3）兩種粒度單位，分別組成以下兩種可實現的柵格系統：

在綜合考慮當下主流分辨率情況、瀏覽器外觀對顯示空間的佔用、人機工程學中對水平視角和聚焦範圍的規定以及8px單位等多種因素後，我們認為960px是一個相對更加合理的頁面寬度。在阿里巴巴中文網站中，推薦使用定寬960px的頁面，去除左右各4px的邊距，中間的可視寬度為952px。

網頁編碼問題與 META

2009-09-14T10:40:00.001+08:00

一個常用又不知道是做什麼用的 META 設定

正確來說，這段 META 是定義「網頁送出的編碼字集」，而不是用來定義「該網頁應該顯示的字集」！

關於各瀏覽器對網頁與文字編碼的處理規則研究整理

當你的網頁編碼為 Big5 字集，但你需要表單送出時用 GB2312 字集送出的話，就可以利用以下步驟完成此任務：

1. 伺服器回應網頁要求時明確指定瀏覽器應顯示的字集

Response.ContentType = "text/html; charset=big5";

2. 在網頁 HTML 中加入 META 標籤，明確指定 Content-Type 與字集

<[meta http-equiv="Content-Type" content="text/html; charset=gb2312" /]>

git memo

2009-09-14T06:31:00.001+08:00

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)

2009-09-13T12:02:00.005+08:00

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:

Customize Field Error
可以自訂error msg 的格式

Railscast skill(8)

2009-09-11T11:14:00.005+08:00

Logging Variables

eval 執行後面的 ruby code
binding 可以把當時的環境存起來

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

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

Railscast skill (7)

2009-09-10T21:40:00.003+08:00

in_groups_of
定量分組時在用的

group_by Month
group_by 好棒, 想用啥分類就分

Railscast skill (6)

2009-09-10T15:11:00.006+08:00

Restricting Access

helper_method 可以把某些controller 的method 弄到helper 一起用

Console Tricks

Handling Exceptions

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

Railscast skill (5)

2009-09-10T10:55:00.003+08:00

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,

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

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

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

Railscast skill (4)

2009-09-09T17:51:00.002+08:00

Pretty Page Title

把content_for 弄簡潔了, yield 也要有default

Markaby in Helper
也可以在helper 裡用render :partial 或者是用content_tag 去拼view

oink , logger parser, memory

2009-09-09T16:06:00.002+08:00

oink
Log parser to identify actions which significantly increase VM heap size

可以讓log 多出memory 的紀錄
Feb 08 11:39:54 ey33-s00302 rails[9076]: Memory usage: 316516 | PID: 9076

也可做report 來查哪些request or action 耗 memory 比較多

$ oink --threshold=75 /tmp/logs/* ---- MEMORY THRESHOLD ---- THRESHOLD: 75 MB -- SUMMARY -- Worst Requests: 1. Feb 02 16:26:06, 157524 KB, SportsController#show 2. Feb 02 20:11:54, 134972 KB, DashboardsController#show 3. Feb 02 19:06:13, 131912 KB, DashboardsController#show 4. Feb 02 08:07:46, 115448 KB, GroupsController#show 5. Feb 02 12:19:53, 112924 KB, GroupsController#show 6. Feb 02 13:03:00, 112064 KB, ColorSchemesController#show 7. Feb 02 13:01:59, 109148 KB, SessionsController#create 8. Feb 02 06:11:17, 108456 KB, PublicPagesController#join 9. Feb 02 08:43:06, 94468 KB, CommentsController#create 10. Feb 02 20:49:44, 82340 KB, DashboardsController#show Worst Actions: 10, DashboardsController#show 9, GroupsController#show 5, PublicPagesController#show 5, UsersController#show 3, MediaController#show 2, SportsController#show 1, SessionsController#create 1, GroupInvitesController#by_email 1, MediaController#index 1, PostsController#show 1, PhotoVotesController#create 1, AlbumsController#index 1, SignupsController#new 1, ColorSchemesController#show 1, PublicPagesController#join 1, CommentsController#create

benchmark

2009-09-09T15:40:00.002+08:00

convenient benchmark

在 ~/.irbrc

就可以在consloe 輕鬆的做benchmark
>> benchmark{ User.find(2).records.wake.count}
0.00197 seconds (-1% change)

index , mysql slow qurey

2009-09-09T15:09:00.004+08:00

A grand piano for your violin, 一篇關於哪些地方需要建index 的好文
table indexes in rails

找出 MySQL 哪些 Query 速度較慢
檢查 mysql sql 效能使用 MySQL Slow Queries
MySQL 常用指令筆記(問答)

Railscast skill (3)

2009-09-09T10:56:00.002+08:00

Auto-Complete Association

Screencasts skill (II)

2009-09-08T16:33:00.006+08:00

Dynamic Select Menus
可以用生個javascript stylesheets controller 來動態生js , css
在利用content_for 動態 include

Formatting Time

Performing Calculations on Models

Optimistic Locking

ubuntu, ror, jQuery, css, website memo

RuntimeError: !!! Missing the mysql2 gem

rails + rubber + github + amazon ec2 free tier step by step

fb comment

rails 設定多個 smtp account 寄信

haproxy nginx passenger munin

rails ip 辨識國家

haproxy rails ip

capistrano path rake fail

delayed_job capistrano production fail

rmagic cannot open shared object file: No such file or directory

nginx passenger config

改變預設的cache 目錄

[Ptt][心得] Restful下遇到params[:id]含有.的解法

paramter change permanently, header status

Practical Rails Social Networking Site memo (2)

Practical Rails Social Networking Site memo

check timezone valid

migration

rjs page

respond_to jsonp

Bootstrap Initializer

rescue_from Exception Handlers

Top 8 SQL Best Practices

SQL Server TSQL Coding Conventions, Best Practices, and Programming Guidelines

rails performance memo

That’s Not a Memory Leak, It’s Bloat; refactor

respond_to

Restful memo

Rails Best Practices

Advanced Active Record Techniques: Best Practice Refactoring

Rails Code Review PDF

Enable or fix logging for HAProxy load balancer

request host, query paramters, header

multi-step

render outside your controller

Turning web server configuration

redirect permanent

META HTTP-EQUIV="refresh" 實現網頁自動跳轉

rails default environment

nginx memo

restart nginx

transcation

ssl apache nginx configuration

nginx , page cache, capistrano

Moneta, memcache

heroku 上 你要 它卻沒有的gem

Changing Your Origin

fb comment

write rails plugin memo

Paginating with the Fragment Cache

group count

fbml in iframe canvas by serverfbml

Resizable IFrame

rjs page call

Problem updating to Rubygems 1.3.5

facebook iframe use fbml

include vs joins

dynamic asset_host

google seo memo

simple memo, initializer run

Symmetric Encryption vs Asymmetric Encryption

facebook 發post ( story ) 到 wall

Authorizing Applications, share button

Choosing between an FBML or IFrame Application(2)

Choosing between an FBML or IFrame Application(1)

找該加index 的地方

check index exist

mustache 把view logic 的部份再拆出來

Ruby on Rails Code Quality Checklist

Install any HTML theme/template into your Rails app

[Scale] Scale Frontend 應該注意的五件事

clearance 的 generator

JavaScript 中的 document.createDocumentFragment

ruby binary code

console tips

has_many , time now, assocation

跨browser 播音樂

Facebook app memo

Session Management

heroku 上你要它卻沒有的gem

網頁編碼問題與 META