Some howtos

howto.txt

* setup a git repository

=============================
> reset to "original head" - master before the merge
  $ git reset --hard ORIG_HEAD
> rebase (go to new branch then merges "base" branch to the new branch)
  $ git checkout new-branch
  $ git rebase base-branch
  # now new-branch is merged with base-branches and is a continuum 
> checkout and create branch at the same time
  $ git checkout -b new-branch

> show branches
  $ git branch
> create branch
  $ git branch my-branch
> switch branch
  $ git checkout my-branch
> delete branch
  $ git branch -d branch-to-delete

> see git gui
  $ gitk --all
> see log
  $ git log 
  $ git log -p # actual diff of changes in contents
> commit with diff:
  $ git commit -v # includes diff of changes

=============================
> heroku
    heroku create --stack bamboo-mri-1.9.2 my-project
> for testing one class only
    $: << 'test'
> console (after git push)
    heroku console
      >> ENV['DATABASE_URL'

=============================

~/tinker/howto.txt

> finding files by name
  $ find . -name howto.txt

> using rvm sandboxed (taken from play-by-play John Barnette - emacs guru)
  * make .rvmrc file in the directory you want to use a specific ruby version
    which should contain:
   
    rvm use --create ruby-1.9.2-p180@your_gemset

  * gem update --system # should be done... 
  * install gems
  * Rakefile (see ~/tinker/gumflap/Rakefile) 

> fossil 
  $ fossil new ~/your_repo_dir/proj.fossil
  $ fossil open ~/your_repo_dir/proj.fossil
  $ fossil stat
  $ fossil serve # host project
  $ fossil ui    # with web?

> Programming tips
  * make integration test first to know how your program works
  * Vjd in vim to remove multiple blank lines
  * CTRL-z from vim to shell, fg from shell (foreground) back to vim
  * map ",t" to save and run(!) spec on current file(%)<cr>
      :map ,t :w\|!rspec %<cr>
  * omnicomplete CTRL-x CTRL-l
  * testing: 
    - ON RED change message or make pass  
    - ON GREEN refactor
    - change message with new tests?

> using git:
  $ git init
  $ git add [files]
  $ commit -m 'first commit'
  $ git remote add origin git@github.com:baloi/ruby_tinker.git
  $ git push -u origin master

> install redis server
  ( from http://blog.grayproductions.net/articles/setting_up_the_redis_server)

  $ sudo port selfupdate
  $ sudo port upgrade outdated
  $ sudo port install wget
  $ wget http://redis.googlecode.com/files/redis-2.2.5.tar.gz
  $ sudo cp redis-server redis-cli redis-benchmark /usr/local/bin/
  
  now the client library
  $ gem sources -a http://gems.github.com
  $ sudo gem install ezmobius-redis 
  
  run server 
  $ redis-server redis.conf

  uncomment bind 127.0.0.1 # if connecting only locally

  set maxclients and timeout values to reclaim resources...

=============================
~/ruby_rails/howto_rails.txt

> selecting from array through condition
 
  selected_items = all_items.select{|item| item.is_ok?}

  If item.is_ok is true then this will be appended to selected_items array 

> easily create CRUD through scaffold:
  1. create table
	create table products(
	  id INTEGER PRIMARY KEY AUTOINCREMENT not null,
	  title varchar(100) not null,
	  description text not null,
	  image_url varchar(200) not null,
	  price decimal(10,2) default 0);
  2. configure config/database.yaml:
	development:
	adapter: sqlite3
	database: depot.sql
	timeout: 5000
  3. generate the scaffold:
	ruby script/generate scaffold Product Admin
     - note that model Product corresponds to table products and Admin 
       is the name of the controllermodel 


HOWTO CREATE a model and migrate it to a database
  $ ruby script/generate model message title:string text:text recipient_id:integer
  $ rake db:migrate
      (use 'rake db:rollback' if you edit your migration and want to run it)
  $ ruby script/generate scaffold Message Inbox
  $ rake db:test:prepare

HOWTO modify models
  MORE:
  $ ruby script/generate migration AddReferenceToPerson
	class AddReferenceToPerson < ActiveRecord::Migration
	  def self.up
	    add_column :table_name_plural, :column_name, :type
    end
	  def self.down
	    remove_column :table_name_plural, :column_name
	  end
	end

HELPERS for MIGRATIONS
  - create_table and change_table
  create_table :products do |t|
    t.timestamps
  end

  change_table :products do |t|
    t.timestamps
  end
 
  create_table :products do |t|
    t.references :category
  end

METHODS in active record migrations:
  > create_table
  > change_table
  > drop_table
  > add_column
  > change_column
  > rename_column
  > remove_column
  > add_index
  > remove_index

HOWTO TEST RAILS with rake
  $ rake test_units
  $ rake test_functional
  $ rake  # all tests...

============

   Now we have a many to many relationship with Resident and Session models. 
   It was created this way... 
   (from developer.apple.com/tools/developrailsleopard.html):

After creating models for resident and session: 
   $ ruby script/generate model [resident/session] [attributes...]
   $ rake db:migrate

Create resource resident_session as a joining table

   $ ruby script/generate resource resident_session session_id:integer resident_id:integer
  
   - careful of the naming for session_id and resident_id to corresponding
     tables(resident and session) to be joined as many-to-many   

   $ rake db:migrate

Then add the has_many and belongs to stuff in the models

class Resident < ActiveRecord::Base
  has_many :resident_sessions
  has_many :sessions, :through => :resident_sessions
end

class ResidentSession < ActiveRecord::Base
  belongs_to :resident
  belongs_to :session
end

class Session < ActiveRecord::Base
  has_many :resident_sessions
  has_many :residents, :through => :resident_sessions
end
============
ruby script/console:
>> r1 = Resident.create(:name => "dado")
>> s1 = Session.create(:description => "first session")
>> r1.resident_sessions.create(:session => s1)

This all means that:
> We use this to create to create a "join" table for a many to many relationship
  between two models (first_model and other_model).
  $ script/generate resource join_table_name first_model_name_id:integer other_model_name_id:integer
  $ rake db:migrate
> We edit the models join_table, first_model & other_model and adding
  1. belongs_to (on join_model) 
  2. has_many :join_model(s) + has_many :other_model, :through => join_model(s)

============
HOWTO create select for a one-to-many like "group has one therapist, therapist
  has many groups"

<p><label for="group_therapist_id">Therapist</label><br/>
<%= select 'group', 'therapist_id', @therapists %></p>

  - Note: foreign key should have '_id' suffix

============

HOWTO "fuzzy search" active record models
  class Session < ActiveRecord::Base
    def self.find_all_groups   
      find(:all, :conditions => ["type LIKE ? ", "%Group%"])
    end
  end
  class Group < Session;

============

RUN A single test from commandline
> ruby test/unit/product_test.rb --name test_calculate_tax
 
============

Hidden fields:
hidden_field(:variable, :attribute, :options)

============

selection lists:

> prep list

  @residents = Resident.find(:all).map {|t| [t.name, t.id] }

> in the view

  <%= select 'resident', 'id', @residents  %></p>

============

link_to alternative if you have to set additional post params
  > in this example :resident_id is the other param I want to add to post..
        <%= button_to "Remove", { :action => 'remove_resident',
                :id => @session.id, :resident_id => resident.id },
                :confirm => "Are you sure?", :method => :post %>


============

ActiveSupport::JSON

  require 'gems'
  require 'active_support'

  j = ActiveSupport::JSON
  j.encode('test')
  
  j.decode()

=============

Restclient
 require 'rubygems'
 require 'restclient'

 RestClient.get 'http://localhost:3000/customers.xml'
 RestClient.delete 'http://localhost:3000/customers/1.xml'

=============

HOWTO make netzke (rails with extjs) work in rails:

> download Ext 3.3.0 and contents in public/javascripts/extjs

> Add netzke to gemfile

  gem 'netzke-core', :git => "git://github.com/skozlov/netzke-core.git"
  gem 'netzke-basepack', :git => "git://github.com/skozlov/netzke-basepack.git"

> update bundle
 
  $ bundle install

> install will_paginate to prevent errors in netzke:

  $ script/plugin install git://github.com/mislav/will_paginate.git

> in config/routes.rb
  [MyApp]TaskManager::Application.routes.draw do
    netzke
    root :to => "welcome#index"
    # ...
  end

> generate controller

  rails g controller welcome index

> replace default javascript and stylesheet inclusions with netzke_init helper

  <html>
  <head>
    <title>Netzke Task Manager</title>

    # baloi start
    <%= netzke_init %>
    <%= csrf_meta_tag %>
    # baloi end

  </head>
  <body>
  <%= yield %>
  </body>
  </html>

> create the model

  $ rails g model Task done:boolean name:string notes:text priority:integer due:date

> Now comes the cool part: embed the netzke grid panel:
  In app/views/welcome/index.html.erb

  <%= netzke :tasks, :class_name => "Basepack::GridPanel", :model => "Task" %>

!!WHOAAA!

=============
POSTGRES:

###########################################################
# A startup item has been generated that will aid in
# starting postgresql90-server with launchd. It is disabled
# by default. Execute the following command to start it,
# and to cause it to launch at startup:
#
# sudo port load postgresql90-server
###########################################################

To create a database instance, after install do
 sudo mkdir -p /opt/local/var/db/postgresql90/defaultdb
 sudo chown postgres:postgres /opt/local/var/db/postgresql90/defaultdb
 sudo su postgres -c '/opt/local/lib/postgresql90/bin/initdb -D /opt/local/var/db/postgresql90/defaultdb'


=============

POSTGRES via Brew

If builds of PostgreSQL 9 are failing and you have version 8.x installed,
you may need to remove the previous version first. See:
  https://github.com/mxcl/homebrew/issues/issue/2510

To build plpython against a specific Python, set PYTHON prior to brewing:
  PYTHON=/usr/local/bin/python  brew install postgresql
See:
  http://www.postgresql.org/docs/9.0/static/install-procedure.html


If this is your first install, create a database with:
    initdb /usr/local/var/postgres

If this is your first install, automatically load on login with:
    mkdir -p ~/Library/LaunchAgents
    cp /usr/local/Cellar/postgresql/9.0.4/org.postgresql.postgres.plist ~/Library/LaunchAgents/
    launchctl load -w ~/Library/LaunchAgents/org.postgresql.postgres.plist

If this is an upgrade and you already have the org.postgresql.postgres.plist loaded:
    launchctl unload -w ~/Library/LaunchAgents/org.postgresql.postgres.plist
    cp /usr/local/Cellar/postgresql/9.0.4/org.postgresql.postgres.plist ~/Library/LaunchAgents/
    launchctl load -w ~/Library/LaunchAgents/org.postgresql.postgres.plist

Or start manually with:
    pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start

And stop with:
    pg_ctl -D /usr/local/var/postgres stop -s -m fast