DZone Snippets: Err's Code Snippets

Run script/console Remotely with Capistrano

err (Chris Wanstrath) — Mon, 28 Aug 2006 05:52:15 GMT

From http://errtheblog.com/post/21.
Allows you to execute script/console remotely through Capistrano. Not for use on multi-machine :roles.



desc "remotely console" 

task :console, :roles => :app do

  input = ''

  run "cd #{current_path} && ./script/console #{ENV['RAILS_ENV']}" do |channel, stream, data|

    next if data.chomp == input.chomp || data.chomp == ''

    print data

    channel.send_data(input = $stdin.gets) if data =~ /^(>|\?)>/

  end

end

Tail Multiple Log Files At Once With Capistrano

err (Chris Wanstrath) — Mon, 28 Aug 2006 05:50:52 GMT

From http://errtheblog.com/post/21
Allows you to aggregate the tailing of multiple production log files with one Capistrano task

Stick it in deploy.rb:



desc "tail production log files" 

task :tail_logs, :roles => :app do

  run "tail -f #{shared_path}/log/production.log" do |channel, stream, data|

    puts  # for an extra line break before the host name

    puts "#{channel[:host]}: #{data}" 

    break if stream == :err    

  end

end

Block to Partial Rails Helper

err (Chris Wanstrath) — Mon, 28 Aug 2006 05:49:13 GMT

From http://errtheblog.com/post/13.
Create a helper which takes a block and renders that block within the context of a partial.

Create this helper:



def block_to_partial(partial_name, options = {}, &block)

  options.merge!(:body => capture(&block))

  concat(render(:partial => partial_name, :locals => options), block.binding)

end

Create this helper, too:



def sidebar_module(title, options = {}, &block)

  block_to_partial('shared/sidebar_module', options.merge(:title => title), &block)

end

Create this partial (app/views/shared/_sidebar_module.rhtml):



 class="sidebar_module">

  <%= title %>

  <%= body %>

Use it in your views:



<% sidebar_module 'Recent Stories' do %>

  <%= render :partial => 'recent_stories', :collection => @recent_stories %>

<% end %>

Parse XML with Hpricot

err (Chris Wanstrath) — Mon, 28 Aug 2006 05:45:47 GMT

From http://errtheblog.com/post/8
Simple XML is basically HTML with random tags, yeah? Parse it with Hpricot!

Your XML:

The code:



require 'hpricot'

FIELDS = %w[SKU ItemName CollectionNo Pages]



doc = Hpricot.parse(File.read("my.xml"))

(doc/:product).each do |xml_product|

  product = Product.new

  for field in FIELDS

    product[field] = (xml_product/field.intern).first.innerHTML

  end

  product.save

end

rake remigrate

err (Chris Wanstrath) — Mon, 28 Aug 2006 05:42:56 GMT

From http://errtheblog.com/post/3
Drops your database, recreates it, runs all migrations, then loads fixtures. Heroic.



desc "Drop then recreate the dev database, migrate up, and load fixtures" 

task :remigrate => :environment do

  return unless %w[development test staging].include? RAILS_ENV

  ActiveRecord::Base.connection.tables.each { |t| ActiveRecord::Base.connection.drop_table t }

  Rake::Task[:migrate].invoke

  Rake::Task["db:fixtures:load"].invoke

end