ruby

Flattening hash into string in Ruby

Is there a way to flatten a hash into a string, with optional delimiters between keys and values, and key/value pairs? For example, print {:a => :b, :c => :d}.flatten('=','&') should print a=b&c=d I wrote some code to do this, but I was wondering if there was a neater way: class Hash def flatten(keyvaldelimiter, entrydelimiter) ...

Implement Apect-oriented-like nested around filters with Ruby?

I'm trying to write a class that supports nested around filters without introducing an Aspect-oriented library. class Foo attr_accessor :around_filter def initialize #filters which wrap the following one are the ones with interesting logic #vanilla do-nothing filter @around_filter = lambda { yield } # or lambda {|&blk| ...

upload csv file with delayed job.

I have a rake task loaddata.rake. require File.join(File.dirname(__FILE__), 'load_test_data.rb') namespace :test do desc "Insert test data into the database" task(:loadtest => :environment) do puts "environment = #{RAILS_ENV}" puts "load_test_data "; load_test_data puts "DONE!" end end I have another fi...

Are there programs that iteratively write new programs?

For about a year I have been thinking about writing a program that writes programs. This would primarily be a playful exercise that might teach me some new concepts. My inspiration came from negentropy and the ability for order to emerge from chaos and new chaos to arise out of order in infinite succession. To be more specific, the ...

Is there some sort of mechanism in Phusion Passenger to keep whole applications from going down?

Hi there, The following is beginning to become a huge problem for us. We have about 15 Rails applications for our enterprise, running on a massive server. The problem occurs when two or three applications are wildly popular and they start taking up all the instances in the PassengerMaxPoolSize. As soon as that happens, other applicatio...

Online job-searching is tedious. Help me automate it.

Many job sites have broken searches that don't let you narrow down jobs by experience level. Even when they do, it's usually wrong. This requires you to wade through hundreds of postings that you can't apply for before finding a relevant one, quite tedious. Since I'd rather focus on writing cover letters etc., I want to write a program t...

Setting an instance variable from a block

How would I achieve something like below so that when I set the s variable within the block, it also sets the @subject instance variable in my Topic class? class Topic def subject(&blk) blk.call(@subject) if block_given? @subject unless block_given? end end my_topic = Topic.new p my_topic.subject #=> nil my_topic.subject ...

ActiveRecord :has_many associations and === operator

Can someone explain me this Ruby on Rails puzzle? class Post < ActiveRecord::Base has_many :comments end Post.first.comments.class => Array Array === Post.first.comments => false Array === [ 1 ] => true ...

Problem with rake jobs:work.

while i am running rake jobs:work. I am getting this error. ** Invoke jobs:work (first_time) ** Invoke merb_env (first_time) ** Execute merb_env ** Invoke environment (first_time) ** Execute environment rake aborted! uninitialized constant Delayed C:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/dependencies.rb:443...

delayed job problem in rails.

My controller data_files_controller.rb def upload_balances DataFile.load_balances(params) end My model data_file.rb def self.load_balances(params) # Pull the file out of the http request, write it to file system name = params['Filename'] directory = "public/uploads" errors_table_name = "snapshot_errors" upload_file = File.join(...

hpricot segfault?

Any idea why hpricot might segfault on this page? trial_url = 'http://www.controlled-trials.com/ISRCTN56071145/' doc = Hpricot(open(trial_url)) produces: /Users/ap257/.gem/ruby/1.8/gems/hpricot-0.8.2/lib/hpricot/parse.rb:33: [BUG] Segmentation fault ruby 1.8.7 (2009-06-08 patchlevel 173) [universal-darwin10.0] Abort trap Please cou...

Ruby on Rails on Windows: gem install fails, no output at all

I installed ruby through the windows installer yesterday. All seemed fine. Today, I went installing the rmagick win32 gem like so: c:\ruby187\bin\gem install rmagick-2.7.1-x86-mswin32.gem in the directory with the gem. That also seemed to work fine, got the familiar 1 gem installed Installing ...[all the ri and other docs]. But after...

Modifying an inherited Rails association

I have a Team class that inherits from a Group class. Both Team and Groups have memberships through the same association. However, I need to run a method after a Team memberships is added but not a Group. I currently have something like this: class Group < ActiveRecord::Base has_many :memberships, :class_name => 'Connec...

How do I include Responder in ActionController::Metal in Rails 3?

I'm working a Rails 3 controller that has a very specific, limited purpose, and all I need is for it to respond_to :json. This screencast says my controller can inherit from ActionController::Metal, and then just include the functionality I need to make things faster: http://rubyonrails.org/screencasts/rails3/action-controller When my...

Ruby/IRB self help

I'm new to Ruby - what tricks can I use to help me find documentation on a object I'm working with? Normally I just do a_var.class or a_var.methods and try to guess what I need or search the web for documentation. Are there other methods or modules that might help? ...

Taking out a subpart from Enumerable

I often want to take out a subpart from an Enumerable. The subpart is sometimes at the beginning and sometimes the end of the original Enumerable instance, and the length used to specify the subpart is sometimes that of the subpart and sometimes its complement. That gives four possibilities, but I only know how to do three of them. Is th...

Trying to manually recreate a simple generate/scaffolding script

I'm trying to understand Rails from the ground up. I want to learn how to manually create basic show-all/show-single/CRUD functionality in the framework. I currently am working on the display-all functionality, but am stopped by an error when I try to request all items in the Products db Here are the steps I've taken so far: script/g...

Did we really always need to use Ruby/ rails plugin?

I been intersted in ruby and rails lately but what I always encounter in blog/ podcast / book is they will always teach how to use ruby or rails plugin/ ruby instead of writing one. Did we really always need to use plugin, even thing like authorization? Authenticate? Is it really waste time Or hard to write from start? Then if it hard an...

Where goes signal sent to process which called system?

Given a very simple ruby script: child = fork do system 'sleep 10000' end 5.times do sleep 1 puts "send kill to #{child}" Process.kill("QUIT", child) end QUIT signal is just lost. Where does it go? Something with default handler which just ignores it? How to send signal to all processes created by that fork? Is it possible t...

Is there any problem installing Ruby 1.9.1 when i already have installed ruby 1.8.7 running with rails?

I have ruby on rails installed on my Desktop running ruby 1.8.7 and rails 2.3.8 i want to know is installing Ruby 1.9.1 version will mess up with my Rails apps? Thx. ...