DZone Snippets: rails code

TextMate snippet for load_model methods in Rails controllers

nicwilliams (Dr Nic Williams) — Mon, 07 Jan 2008 00:26:45 GMT

With nested routes, I find I create a lot of controller methods like:



def load_user

  @user = User.find(params[:user_id]) if params[:user_id]

Here's a TextMate snippet, so you can just type: defmodel, TAB, user, TAB, and you're done.

Snippet:



def load_${1:model}

	@$1 = ${1/[[:alpha:]]+|(_)/(?1::\u$0)/g}.find(params[${2::$1_}id])${3: if params[:$1_id]}

end

Activation: defmodel
Scope: source.ruby.rails

I have this in the Ruby on Rails bundle, but you can put it anywhere. Its the scope that is important.

Upgrade rubygems and/or specific gems themselves via capistrano

nicwilliams (Dr Nic Williams) — Wed, 19 Dec 2007 22:10:32 GMT

When a latest RubyGems is released (e.g. 0.9.5 recently) or Rails (e.g. 2.0.2) you might want to push those upgrades to all your production machines.

Add these two tasks to your deploy.rb capistrano file (add namespaces for cap2.0 if you like)



  desc "Updates RubyGems version"

  task :gem_update_system do

    sudo "gem update --system"

  end



    

  desc "Install a RubyGem from remote source"

  task :gem_install do

    puts "USAGE: GEM=gemname cap gems_install" and next unless ENV['GEM']

    sudo "gem install #{ENV['GEM']} --no-ri --no-rdoc"

  end

To upgrade rubygems and rails, for example:



cap gem_update_system

GEM=rails cap gem_install

Auto-populate socket value in rails database.yml using TextMate snippet

nicwilliams (Dr Nic Williams) — Mon, 16 Jul 2007 07:30:51 GMT

When using mysql for rails apps, you may need a socket: value. I can never remember mine. So I added a TextMate snippet to find it. (read below for non-TextMate)

Snippet text:



socket: `mysql_config --socket`

Activation: socket:

Scope selector: source.yaml - string

Usage:

In your database.yml, go to the line socket: , delete any blank spaces til the cursor is at the colon, then press TAB and wait. The line will be updated with the socket location.

Non-TextMate

If you don't have textmate, you can get your socket location using:



mysql_config --socket

And paste the result into your database.yml

Dump postgres production data into development database

nicwilliams (Dr Nic Williams) — Sun, 06 May 2007 09:00:17 GMT

When bug requests come in, its great to grab a copy of the current production (or system test env) data and sync it into your development database.

Here's a capistrano recipe for postgresql:



desc "Dumps target database into development db"

task :sync_db do

  env   = ENV['RAILS_ENV'] || ENV['DB'] || 'production'

  file  = "#{application}.sql.bz2"

  remote_file = "#{shared}/log/#{file}"

  run "pg_dump --clean --no-owner --no-privileges -U#{db_user} -h#{db_host} #{db_name}_#{env} | bzip2 > #{file}" do |ch, stream, out|

    ch.send_data "#{db_password}\n" if out =~ /^Password:/

    puts out

  end

  puts rsync = "rsync #{user}@#{domain}:#{file} tmp"

  `#{rsync}`

  puts depackage = "bzcat tmp/#{file} | psql #{local_db_dev}"

  `#{depackage}`

end

Reset user password based on another users

nicwilliams (Dr Nic Williams) — Fri, 04 May 2007 13:45:54 GMT

When you first create an app you might not have time *cough* to add special user password reset features. Especially if you don't have many users.

Here's a quick script to set the password of a user to another user (say a manually created user 'tester' with a known password).



namespace :user do

  desc 'Reset user (USER=username) password to that of username "tester" (or FROM=username env)'

  task :reset => :environment do

    reset_username = ENV['USER']

    unless ENV['USER']

      puts 'Require "USER=username" for user to be reset'

      next

    end

    reset_user     = User.find_by_username reset_username

    unless reset_user

      puts "Cannot find user: #{reset_username}"

      next

    end

    from_username  = ENV['FROM'] || 'tester'

    from_user      = User.find_by_username from_username

    unless from_user

      puts "Cannot find user: #{from_username}"

      next

    end

    

    reset_user.crypted_password = from_user.crypted_password

    reset_user.salt             = from_user.salt

    reset_user  .save

    puts 'User password reset'

  end

end

Capistrano logs

nicwilliams (Dr Nic Williams) — Tue, 10 Apr 2007 20:09:05 GMT

To get the last n lines from a remote log file, use this task

Usage: cap log [-s lines=100] [-s rails_env=production]
So, "cap log" returns 100 lines from production.



desc "Returns last lines of log file. Usage: cap log [-s lines=100] [-s rails_env=production]"

task :log do

  lines     = configuration.variables[:lines] || 100

  rails_env = configuration.variables[:rails_env] || 'production'

  run "tail -n #{lines} #{app_dir}/log/#{rails_env}.log" do |ch, stream, out|

    puts out

  end

end

Migrate rhtml views into erb views within subversion repository

nicwilliams (Dr Nic Williams) — Sun, 04 Mar 2007 07:57:36 GMT

From Brandon Keepers:

To migrate rhtml views into erb views within subversion repository:



Dir.glob('app/views/**/*.rhtml').each do |file|

  puts `svn mv #{file} #{file.gsub(/\.rhtml$/, '.erb')}`

end

Create classes at runtime

nicwilliams (Dr Nic Williams) — Thu, 10 Aug 2006 22:49:44 GMT

Dr Nic's Magic Models adds automatic ActiveRecord generation if you haven't defined a model, and for all ActiveRecords it can generate associations and validations on-the-fly based on the database schema (the table and column definitions).

It does this with some interesting Ruby meta-programming.

For example, if you want to create a new class at runtime, and assign it a superclass, try the following:



  def create_class(class_name, superclass, &block)

    klass = Class.new superclass, &block

    Object.const_set class_name, klass

  end

With this code, you can create a class as follows:



create_class('Person', ActiveRecord::Base) do

  set_table_name :people



  def fullname

    "#{firstname} #{lastname}" # assuming the people table has firstname,lastname columns

  end

end