Search Results

Search found 9835 results on 394 pages for 'ruby on rails3'.

Page 31/394 | < Previous Page | 27 28 29 30 31 32 33 34 35 36 37 38  | Next Page >

• How to add a has_many association on all models

  - by joshsz

  Right now I have an initializer that does this: ActiveRecord::Base.send :has_many, :notes, :as => :notable ActiveRecord::Base.send :accepts_nested_attributes_for, :notes It builds the association just fine, except when I load a view that uses it, the second load gives me: can't dup NilClass from: /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:2184:in `dup' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:2184:in `scoped_methods' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:2188:in `current_scoped_methods' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:2171:in `scoped?' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:2439:in `send' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:2439:in `initialize' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/reflection.rb:162:in `new' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/reflection.rb:162:in `build_association' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/associations/association_collection.rb:423:in `build_record' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/associations/association_collection.rb:102:in `build' (my app)/controllers/manifests_controller.rb:21:in `show' Any ideas? Am I doing this the wrong way? Interestingly if I move the association onto just the model I'm working with at the moment, I don't get this error. I figure I must be building the global association incorrectly.

  Read the article

• gem install giving error that I can't change permissions.. chown and chmod not working

  - by user2321289

  so I am trying to install hmac gem install ruby-hmac -v 0.4.0 I am getting the following error message: You don't have write permissions into the /opt/rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1 directory So the output from ls -l is as such: ubuntu@ip-10-38-121-211:~/workspace/cf-release$ sudo ls -l /opt/rbenv/versions/1.9.3-p448/lib/ruby/gems/ I perform a chown on this directory: sudo chown -R ubuntu:ubuntu /opt/rbenv/versions/1.9.3-p448/lib/ruby/gems/ Try to install the gem: ubuntu@ip-10-38-121-211:~/workspace/cf-release$ sudo chown -v ubuntu:ubuntu /opt/rbenv/versions/1.9.3-p448/lib/ruby/gems/ ownership of `/opt/rbenv/versions/1.9.3-p448/lib/ruby/gems/' retained as ubuntu:ubuntu I do another ls -l on the directory: ubuntu@ip-10-38-121-211:~/workspace/cf-release$ ls -l /opt/rbenv/versions/1.9.3-p448/lib/ruby/gems/ total 4 d--------- 8 ubuntu ubuntu 4096 Nov 1 20:43 1.9.1 Doing a chmod 777 to make the directory writeable: ubuntu@ip-10-38-121-211:~/workspace/cf-release$ sudo chmod -v 777 /opt/rbenv/versions/1.9.3-p448/lib/ruby/gems/ mode of `/opt/rbenv/versions/1.9.3-p448/lib/ruby/gems/' retained as 0777 (rwxrwxrwx) ubuntu@ip-10-38-121-211:~/workspace/cf-release$ ls -l /opt/rbenv/versions/1.9.3-p448/lib/ruby/gems/ total 4 d--------- 8 ubuntu ubuntu 4096 Nov 1 20:43 1.9.1 Any idea as to why this would be acting up like this? I am at a loss here.. any help appreciated

  Read the article

• Rails 3.0.0.beta Install problem: can't find executable rails

  - by JZ

  I'm trying to install the rails 3.0.0.beta and I'm running into this issue: justins-mac-: justinz$ ruby -v ruby 1.8.7 (2008-08-11 patchlevel 72) [universal-darwin10.0] justins-mac-justinz$ rails -help /Library/Ruby/Site/1.8/rubygems.rb:384:in `bin_path': can't find executable rails for rails-3.0.0.beta (Gem::Exception) from /usr/bin/rails:19 justins-mac-justinz$ rails -v /Library/Ruby/Site/1.8/rubygems.rb:384:in `bin_path': can't find executable rails for rails-3.0.0.beta (Gem::Exception) from /usr/bin/rails:19 justins-mac-justinz$ Any clues as to what is going on here?

  Read the article

• Installing Ruby 1.9.3 OSX 10.7.4 breaks after altering PATH

  - by R V

  I was having trouble installing ruby 1.9.3-p194 from ruby 1.8.7 on my mac osx 10.7.4. I have was trying to fix my homebrew after running "brew doctor" and got the message of "/usr/bin occurs before /usr/local/bin This means that system-provided programs will be used instead of those provided by Homebrew. The following tools exist at both paths: c++-4.2 cpp-4.2 erb g++-4.2 gcc-4.2 gcov-4.2 gem i686-apple-darwin11-cpp-4.2.1 i686-apple-darwin11-g++-4.2.1 i686-apple-darwin11-gcc-4.2.1 irb rake rdoc ri ruby testrb" I fixed it by entering the following, which I found on another stackoverflow answer: export PATH="/usr/local/bin:/usr/local/sbin:~/bin$PATH" Lo and behold! when I typed that ruby updates to 1.9.3-p194. Ruby files seem to compile and run just fine. However, afterward, my navigation around terminal is messed up severely. For instance I can't do the command "open example_file.html" and have the file pop up in Chrome, instead I get the error: "-bash: open: command not found" Also, when I change directory, I get an error, inputting "$ cd desktop" yields the output, "-bash: dirname: command not found" but the directory does then changes... strange. When I exit out of a terminal window all this resets. I'm back to Ruby 1.8.7, have to use the PATH command again to update to 1.9.3, command line navigation gets broken again. Any guidance on how to remedy so I can use 1.9.3-p194 and also have normal terminal navigation would be greatly appreciated.

  Read the article

• Fixed ruby/mysql connection with new libmysql.dll, and broke Apache in the process

  - by jmtoporek

  Ok so bit of background - all my development has been on a local Windows 7 machine. I had Apache with PHP/MySQL running with no issues. Been using ruby (1.9.3 and latest rails release 3.2.9) with built in webrick server, but had a devil of a time connecting to mysql. Did some research, updated my libmysql.dll file in c:/ruby/bin and it worked! Very happy... except now Apache stopped working. In my attempt to resolve the issue I found an older copy of libmysql.dll, renamed the new file, copied the old file back to c:ruby/bin and apache works, ruby does not. So I can take this ass backwards approach but obviously this seems pretty stupid. I was surprised that Apache was using the dll file in ruby/bin folder. I presume this is related to path variables perhaps? I guess I was hoping someone could direct me as to how I can use one dll file for apache and another for ruby. Or if you have some other smarter approach - I've smart enough to follow directions to install apache from scratch and enable php on windows as well as ubuntu, but I'm not much of a sys admin, just a semi competent web developer.

  Read the article

• error when installing mysql ruby gem on OSX 10.6.3

  - by kapil.israni

  So I am getting the same issue as mentioned here - http://stackoverflow.com/questions/1366746/gem-install-mysql-failure-in-snow-leopard But I haven't been able to get it fixed using the answers on this link. Here's a brief history - I had MAMP on my machine, but now I downloaded the latest MySQL from mysql.com and installed version 5.1.46 this new version runs fine and client "mysql" is able to connect and I also have XCode v3.2.1, since someone mentioned that it can cause issues. Here's the error - **Building native extensions. This could take a while... ERROR: Error installing mysql: ERROR: Failed to build gem native extension. /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb --with-mysql-config=/usr/local/mysql/bin/mysql_config mkmf.rb can't find header files for ruby at /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/ruby.h Gem files will remain installed in /Library/Ruby/Gems/1.8/gems/mysql-2.8.1 for inspection. Results logged to /Library/Ruby/Gems/1.8/gems/mysql-2.8.1/ext/mysql_api/gem_make.out**

  Read the article

• RUBY: Require 'RMagick' not working?

  - by igniteflow

  Hi, I have installed RMagick on OSX via MacPorts and can see it by running 'gem server'. However when I try to include it in my script using require 'rubygems' require 'RMagick' It crashes with the following error message ./RMagick.rb:4:in `show_info': uninitialized constant Magick (NameError) from ./RMagick.rb:24 from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require' from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `require' from ./rmagick.rb:1 from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require' from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `require' from get_pixels.rb:2 Could anyone tell me what I'm doing wrong?

  Read the article

• ruby on rails delajed_job failing with rvm

  - by mottalrd

  I have delayed_job installed and I start the daemon to run the jobs with this ruby script require 'rubygems' require 'daemon_spawn' $: << '.' RAILS_ROOT = File.expand_path(File.join(File.dirname(__FILE__), '..')) class DelayedJobWorker < DaemonSpawn::Base def start(args) ENV['RAILS_ENV'] ||= args.first || 'development' Dir.chdir RAILS_ROOT require File.join('config', 'environment') Delayed::Worker.new.start end def stop system("kill `cat #{RAILS_ROOT}/tmp/pids/delayed_job.pid`") end end DelayedJobWorker.spawn!(:log_file => File.join(RAILS_ROOT, "log", "delayed_job.log"), :pid_file => File.join(RAILS_ROOT, 'tmp', 'pids', 'delayed_job.pid'), :sync_log => true, :working_dir => RAILS_ROOT) If I run the command with rvmsudo it works perfectly If I simply use the ruby command without rvm it fails and this is the output, but I have no idea why this happens. Could you give me some clue? Thank you user@mysystem:~/redeal.it/application$ ruby script/delayed_job start production /usr/local/rvm/gems/ruby-1.9.3-p194/gems/daemon-spawn-0.4.2/lib/daemon_spawn.rb:16:in `kill': Operation not permitted (Errno::EPERM) from /usr/local/rvm/gems/ruby-1.9.3-p194/gems/daemon-spawn-0.4.2/lib/daemon_spawn.rb:16:in `alive?' from /usr/local/rvm/gems/ruby-1.9.3-p194/gems/daemon-spawn-0.4.2/lib/daemon_spawn.rb:125:in `alive?' from /usr/local/rvm/gems/ruby-1.9.3-p194/gems/daemon-spawn-0.4.2/lib/daemon_spawn.rb:176:in `block in start' from /usr/local/rvm/gems/ruby-1.9.3-p194/gems/daemon-spawn-0.4.2/lib/daemon_spawn.rb:176:in `select' from /usr/local/rvm/gems/ruby-1.9.3-p194/gems/daemon-spawn-0.4.2/lib/daemon_spawn.rb:176:in `start' from /usr/local/rvm/gems/ruby-1.9.3-p194/gems/daemon-spawn-0.4.2/lib/daemon_spawn.rb:165:in `spawn!' from script/delayed_job:37:in `<main>'

  Read the article

• bundler/capistrano is not installing gems with correct ruby version

  - by Douglas

  I'm trying to deploy my first app on a server with Capistrano, and I'm a bit lost with managing gemsets and ruby version. These are my (server and workstation) versions : Rails 3.2.8 RVM 1.16.17 Gem 1.8.24 Bundler 1.2.1 pg gem 0.14.1 My gemset are : Gemsets for ruby-1.9.3-p194 (found in /usr/local/rvm/gems/ruby-1.9.3-p194) (default) global = rail3dev20120606 I set the default gemset with : rvm use 1.9.3-p194@rail3dev20120606 --default --passenger When I run a : cap bundle:install The task end with success, but when I do a : gem list There are many missing gems though they are present in my Gemfile. When I go to check my gems in /var/www/opf/shared/bundle/ruby/ I find a folder called 1.9.1 and in /var/www/opf/shared/bundle/ruby/1.9.1/gems/ I can fond all of my needed gems (specified in Gemfile). I'm sure there is a problem with ruby version, but how do I solve this ? At the moment, if I do any rake command, I got a ruby crash [Bug] Segmentation fault, as it try to access the db and using postgresql_adapter. I think as many gems are missing there must have some gem dependencies not verified, and maybe a gem is using an incompatible ruby version 1.9.1 though it expect a 1.9.3. I think the issue is around managing ruby versions and gems. I'm certainly doing some mix with gemset and my capistrano deployement. I'm missing experience and info. Could anybody advise me how to handle this on the server ? What are the best practices ? How am I suppose to update my ruby version ? with Capistrano deploy.rb ? manually ? with/without rvm ? I saw a new version of ruby 1.9.3-p327 has just released. Should I use gemset or not ? What about the :rvm_ruby_string in my deploy.rb. Is it correctly spelled or should I remove the p194 part ? Should I Remove the :rvm_ruby_string ? Keep it ? Use a .rvmrc file ??? I'm really lost and some kind help would be welcome. This is my config/deploy.rb in any case : require 'bundler/capistrano' require File.join(File.dirname(__FILE__), 'deploy') + '/capistrano_database' set :rvm_type, :system set :rvm_ruby_string, 'ruby-1.9.3-p194@rail3dev20120606' require 'rvm/capistrano' set :application, 'opf' set :deploy_to, '/var/www/opf' set :rails_env, 'production' set :user, 'the_user' set :use_sudo, false set :group_writable, false set :scm, :git set :repository, '[email protected]:user/opf.git' set :branch, 'master' default_run_options[:pty] = true set :deploy_via, :remote_cache server '192.168.5.200', :web, :app, :db, :primary => true # If you are using Passenger mod_rails uncomment this: namespace :deploy do task :start do ; end task :stop do ; end task :restart, :roles => :app, :except => { :no_release => true } do run "#{try_sudo} touch #{File.join(current_path,'tmp','restart.txt')}" end end Thanks for any help

  Read the article

• Ruby on Rails App not starting in production mode

  - by Ermin

  Everything works fine in development mode, but when I try to start my app in production mode (RAILS_ENV=production script/server) I get the following error: /opt/ruby1.8/lib/ruby/gems/1.8/gems/searchlogic-2.4.19/lib/searchlogic/named_scopes/conditions.rb:81:in `method_missing': protected method `scope' called for #<Class:0x7f41de524410> (NoMethodError) from /opt/ruby1.8/lib/ruby/gems/1.8/gems/searchlogic-2.4.19/lib/searchlogic/named_scopes/association_conditions.rb:19:in `method_missing' from /opt/ruby1.8/lib/ruby/gems/1.8/gems/searchlogic-2.4.19/lib/searchlogic/named_scopes/association_ordering.rb:27:in `method_missing' from /opt/ruby1.8/lib/ruby/gems/1.8/gems/searchlogic-2.4.19/lib/searchlogic/named_scopes/ordering.rb:30:in `method_missing' from /opt/ruby1.8/lib/ruby/gems/1.8/gems/searchlogic-2.4.19/lib/searchlogic/named_scopes/or_conditions.rb:28:in `method_missing' from /opt/ruby1.8/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:1959:in `method_missing_without_paginate' from /opt/ruby1.8/lib/ruby/gems/1.8/gems/will_paginate-2.3.12/lib/will_paginate/finder.rb:170:in `method_missing' from /opt/ruby1.8/lib/ruby/gems/1.8/gems/acts_as_commentable-3.0.0/lib/comment_methods.rb:12:in `included' from .../app/models/comment.rb:2:in `include' from .../app/models/comment.rb:2 from /opt/ruby1.8/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require' from /opt/ruby1.8/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'... Now it seems to me it that the acts_as_commentable gem is causing this. But how come, it works fine in development mode.

  Read the article

• not able to update ruby (and also not able to install gems)

  - by abhishek

  I am new to ruby. OS: Windows XP Ruby Version --ruby 1.8.6 (2008-08-11 patchlevel 287) [i386-mswin32] When I run gem update --system after installing ruby I am getting this error C:\Documents and Settings\abhisheksreepal>gem update --system Updating RubyGems Updating rubygems-update ERROR: While executing gem ... (Gem::InstallError) invalid gem format for C:/Ruby/lib/ruby/gems/1.8/cache/rubygems-update-1.3.5.gem

  Read the article

• Unable to start the web application from localhost:3000(ruby on rails)

  - by vipin8169

  I had created a demo web application by executing rails tickets and then i executed rails script/server to run it on localhost. Initially i was able to execute the application in the browser by typing localhost:3000 in the address bar, but then I deleted the folder tickets from my hard disk. Now again i created the same folder but when i try to run it using the same command rails script/server it says that vverma@l-vverma:~/railsExp/tickets$ rails script/server create File exists - script/server I tried deleting the script/server file but i still couldn't run the localhost:3000 in the browser Tried rails s as well, it gave the following output:- http://paste.ubuntu.com/1317610/ But still i was unable to run the app on 'localhost:3000' What is the solution to this

  Read the article

• Ruby: implementing alpha-beta pruning for tic-tac-toe

  - by DerNalia

  So, alpha-beta pruning seems to be the most efficient algorithm out there aside from hard coding (for tic tac toe). However, I'm having problems converting the algorithm from the C++ example given in the link: http://www.webkinesia.com/games/gametree.php #based off http://www.webkinesia.com/games/gametree.php # (converted from C++ code from the alpha - beta pruning section) # returns 0 if draw LOSS = -1 DRAW = 0 WIN = 1 @next_move = 0 def calculate_ai_next_move score = self.get_best_move(COMPUTER, WIN, LOSS) return @next_move end def get_best_move(player, alpha, beta) best_score = nil score = nil if not self.has_available_moves? return false elsif self.has_this_player_won?(player) return WIN elsif self.has_this_player_won?(1 - player) return LOSS else best_score = alpha NUM_SQUARES.times do |square| if best_score >= beta break end if self.state[square].nil? self.make_move_with_index(square, player) # set to negative of opponent's best move; we only need the returned score; # the returned move is irrelevant. score = -get_best_move(1-player, -beta, -alpha) if (score > bestScore) @next_move = square best_score = score end undo_move(square) end end end return best_score end the problem is that this is returning nil. some support methods that are used above: WAYS_TO_WIN = [[0, 1, 2], [3, 4, 5], [6, 7, 8], [0, 3, 6], [1, 4, 7], [2, 5, 8],[0, 4, 8], [2, 4, 6]] def has_this_player_won?(player) result = false WAYS_TO_WIN.each {|solution| result = self.state[solution[0]] if contains_win?(solution) } return (result == player) end def contains_win?(ttt_win_state) ttt_win_state.each do |pos| return false if self.state[pos] != self.state[ttt_win_state[0]] or self.state[pos].nil? end return true end def make_move(x, y, player) self.set_square(x,y, player) end

  Read the article

• Distributed transactions and queues, ruby, erlang

  - by chrispanda

  I have a problem that involves several machines, message queues, and transactions. So for example a user clicks on a web page, the click sends a message to another machine which adds a payment to the user's account. There may be many thousands of clicks per second. All aspects of the transaction should be fault tolerant. I've never had to deal with anything like this before, but a bit of reading suggests this is a well known problem. So to my questions. Am I correct in assuming that secure way of doing this is with a two phase commit, but the protocol is blocking and so I won't get the required performance? It appears that DBs like redis and message queuing system like Rescue, RabbitMQ etc don't really help me a lot - even if I implement some sort of two phase commit, the data will be lost if redis crashes because it is essentially memory-only. All of this has led me to look at erlang - but before I wade in and start learning a new language, I would really like to understand better if this is worth the effort. Specifically, am I right in thinking that because of its parallel processing capabilities, erlang is a better choice for implementing a blocking protocol like two phase commit, or am I confused?

  Read the article

• Real-time chat in Ruby on Rails

  - by Skydreamer

  First, I'm sorry because I know this question has been asked many times but I'm still looking forward to finding the answer to my problem. I'd want to implement a Real-time chat for my Rails app but I can't really host the server which handles the sockets. I've tried Faye but it needs a server. I've also heard of pusher but it's limited to 20 users at a time on the chat and I can't really be sure they won't be more. I've thought of irc but I think I can't really embed it into a rails app, maybe it needs sockets... So here's my problem, can I implement a real-time chat without owning a server ? What can you advice me ? Thank you for your answers.

  Read the article

• When to use mixins in Ruby

  - by Gilles

  I am wondering when to use mixins? I have read about them. Many authors compare them to interfaces, abstract classes, etc. Mixins are modules that are mixed-in and modules are a way to group similar methods, constants and classes together. I have seen examples where a module for math functions is created. It makes sense to group and reuse such functions but should I only mix these in a class if I am faced with an inheritance situation? Should I mix these in anytime I want to use them in a class? Should they be used exactly like interfaces in other languages or are there other subtleties?

  Read the article

• What does Ruby have that Python doesn't, and vice versa?

  - by Lennart Regebro

  There is a lot of discussions of Python vs Ruby, and I all find them completely unhelpful, because they all turn around why feature X sucks in language Y, or that claim language Y doesn't have X, although in fact it does. I also know exactly why I prefer Python, but that's also subjective, and wouldn't help anybody choosing, as they might not have the same tastes in development as I do. It would therefore be interesting to list the differences, objectively. So no "Python's lambdas sucks". Instead explain what Ruby's lambdas can do that Python's can't. No subjectivity. Example code is good! Don't have several differences in one answer, please. And vote up the ones you know are correct, and down those you know are incorrect (or are subjective). Also, differences in syntax is not interesting. We know Python does with indentation what Ruby does with brackets and ends, and that @ is called self in Python. UPDATE: This is now a community wiki, so we can add the big differences here. Ruby has a class reference in the class body In Ruby you have a reference to the class (self) already in the class body. In Python you don't have a reference to the class until after the class construction is finished. An example: class Kaka puts self end self in this case is the class, and this code would print out "Kaka". There is no way to print out the class name or in other ways access the class from the class definition body in Python. All classes are mutable in Ruby This lets you develop extensions to core classes. Here's an example of a rails extension: class String def starts_with?(other) head = self[0, other.length] head == other end end Ruby has Perl-like scripting features Ruby has first class regexps, $-variables, the awk/perl line by line input loop and other features that make it more suited to writing small shell scripts that munge text files or act as glue code for other programs. Ruby has first class continuations Thanks to the callcc statement. In Python you can create continuations by various techniques, but there is no support built in to the language. Ruby has blocks With the "do" statement you can create a multi-line anonymous function in Ruby, which will be passed in as an argument into the method in front of do, and called from there. In Python you would instead do this either by passing a method or with generators. Ruby: amethod { |here| many=lines+of+code goes(here) } Python: def function(here): many=lines+of+code goes(here) amethod(function) Interestingly, the convenience statement in Ruby for calling a block is called "yield", which in Python will create a generator. Ruby: def themethod yield 5 end themethod do |foo| puts foo end Python: def themethod(): yield 5 for foo in themethod: print foo Although the principles are different, the result is strikingly similar. Python has built-in generators (which are used like Ruby blocks, as noted above) Python has support for generators in the language. In Ruby you could use the generator module that uses continuations to create a generator from a block. Or, you could just use a block/proc/lambda! Moreover, in Ruby 1.9 Fibers are, and can be used as, generators. docs.python.org has this generator example: def reverse(data): for index in range(len(data)-1, -1, -1): yield data[index] Contrast this with the above block examples. Python has flexible name space handling In Ruby, when you import a file with require, all the things defined in that file will end up in your global namespace. This causes namespace pollution. The solution to that is Rubys modules. But if you create a namespace with a module, then you have to use that namespace to access the contained classes. In Python, the file is a module, and you can import its contained names with from themodule import *, thereby polluting the namespace if you want. But you can also import just selected names with from themodule import aname, another or you can simply import themodule and then access the names with themodule.aname. If you want more levels in your namespace you can have packages, which are directories with modules and an __init__.py file. Python has docstrings Docstrings are strings that are attached to modules, functions and methods and can be introspected at runtime. This helps for creating such things as the help command and automatic documentation. def frobnicate(bar): """frobnicate takes a bar and frobnicates it >>> bar = Bar() >>> bar.is_frobnicated() False >>> frobnicate(bar) >>> bar.is_frobnicated() True """ Python has more libraries Python has a vast amount of available modules and bindings for libraries. Python has multiple inheritance Ruby does not ("on purpose" -- see Ruby's website, see here how it's done in Ruby). It does reuse the module concept as a sort of abstract classes. Python has list/dict comprehensions Python: res = [x*x for x in range(1, 10)] Ruby: res = (0..9).map { |x| x * x } Python: >>> (x*x for x in range(10)) <generator object <genexpr> at 0xb7c1ccd4> >>> list(_) [0, 1, 4, 9, 16, 25, 36, 49, 64, 81] Ruby: p = proc { |x| x * x } (0..9).map(&p) Python: >>> {x:str(y*y) for x,y in {1:2, 3:4}.items()} {1: '4', 3: '16'} Ruby: >> Hash[{1=>2, 3=>4}.map{|x,y| [x,(y*y).to_s]}] => {1=>"4", 3=>"16"} Python has decorators Things similar to decorators can be created in Ruby, and it can also be argued that they aren't as necessary as in Python.

  Read the article

• No rails commands will run

  - by Jeremy

  I am trying to learn rails and haven't used it in the last few weeks but today when I try to run any rails commands such as - 'rails -v' - 'script/server' I get not have reinstalled ruby but the didn't don't have a clue what could be wrong Am on a brand new Macbook Pro Jeremy-Geross-MacBook-Pro:~ Jeremy$ rails -v /Library/Ruby/Site/1.8/rubygems/config_file.rb:172:in merge': can't convert String into Hash (TypeError) from /Library/Ruby/Site/1.8/rubygems/config_file.rb:172:ininitialize' from /Library/Ruby/Site/1.8/rubygems.rb:384:in new' from /Library/Ruby/Site/1.8/rubygems.rb:384:inconfiguration' from /Library/Ruby/Site/1.8/rubygems.rb:634:in path' from /Library/Ruby/Site/1.8/rubygems/source_index.rb:68:ininstalled_spec_directories' from /Library/Ruby/Site/1.8/rubygems/source_index.rb:58:in from_installed_gems' from /Library/Ruby/Site/1.8/rubygems.rb:881:insource_index' from /Library/Ruby/Site/1.8/rubygems/gem_path_searcher.rb:81:in init_gemspecs' from /Library/Ruby/Site/1.8/rubygems/gem_path_searcher.rb:13:ininitialize' from /Library/Ruby/Site/1.8/rubygems.rb:839:in new' from /Library/Ruby/Site/1.8/rubygems.rb:839:insearcher' from /Library/Ruby/Site/1.8/rubygems.rb:838:in synchronize' from /Library/Ruby/Site/1.8/rubygems.rb:838:insearcher' from /Library/Ruby/Site/1.8/rubygems.rb:478:in find_files' from /Library/Ruby/Site/1.8/rubygems.rb:1103 from /usr/bin/rails:9:inrequire' from /usr/bin/rails:9

  Read the article

• Can you explain what's going on in this Ruby code?

  - by samoz

  I'm trying to learn Ruby as well as Ruby on Rails right now. I'm following along with Learning Rails, 1st edition, but I'm having a hard time understanding some of the code. I generally do work in C, C++, or Java, so Ruby is a pretty big change for me. I'm currently stumped with the following block of code for a database migrator: def self.up create_table :entries do |t| t.string :name t.timestamps end end Where is the t variable coming from? What does it actually represent? Is it sort of like the 'i' in a for(i=0;i<5;i++) statement? Also, where is the :entries being defined at? (entries is the name of my controller, but how does this function know about that?)

  Read the article

• How to prepare an interview for Ruby on Rails developer position?

  - by Snehal

  Background about myself: I have about 3 years experience working in Java/J2EE. I am currently pursuing MS in Software Engineering at a reputed university. I have done several classwork projects on Ruby on Rails and can be considered at Intermediate level expertise with ROR. I have an interview coming up next week for a Ruby on Rails developer position at a startup. I have already prepared all the basics of Ruby on Rails but didn't get a lot input on the questions asked for ROR developers. Can you guys help me with the preparation? Any materials, suggestions would be welcome.

  Read the article

• Differences between Ruby on Rails versions? Which should I use?

  - by Stephen Kellett

  I first used Rails when it was not so well known about, in 2005. I did some experimental work with it but it has languished due to lack of time. I'm now thinking of persuing the original idea again (with a new implementation) and when researching the latest Ruby and Ruby-on_Rails versions I see Ruby 1.9.2 and a Rails 3.0 beta. I haven't managed to find a concise description of the differences between any of the Rails major versions. I have looked on the official Rails site and a few others as well. No joy. Maybe i'm looking in the wrong places or for the wrong thing? My project isn't commercial in nature (it's a hobby thing) so the beta nature of Rails 3.0 doesn't put me off. I'd just like to know what the differences are. Can anyone explain please? If it makes any odds to the answer, I'll be working on a Linux box and/or a Windows box.

  Read the article

• How to prepare for an interview for Ruby on Rails?

  - by Snehal

  Background about myself: I have about 3 years experience working in Java/J2EE. I am currently pursuing MS in Software Engineering at a reputed university. I have done several classwork projects on Ruby on Rails and can be considered at Intermediate level expertise with ROR. I have an interview coming up next week for a Ruby on Rails developer position at a startup. I have already prepared all the basics of Ruby on Rails but didn't get a lot input on the questions asked for ROR developers. Can you guys help me with the preparation? Any materials, suggestions would be welcome.

  Read the article

• What's the best way to use SOAP with Ruby?

  - by jcoby

  A client of mine has asked me to integrate a 3rd party API into their Rails app. The only problem is that the API uses SOAP. Ruby has basically dropped SOAP in favor of REST. They provide a Java adapter that apparently works with the Java-Ruby bridge, but we'd like to keep it all in Ruby, if possible. I looked into soap4r, but it seems to have a slightly bad reputation. So what's the best way to integrate SOAP calls into a Rails app?

  Read the article

• Does the OS make a significant difference for Ruby Development ?

  - by Bragaadeesh

  Hi, I have been working in Java for the past 4 years and I am currently switching over to Ruby. I am so excited about it and I feel good to finally get a hands on experience on a scripting language first time. The task assigned to me is to first pick a OS of my choice and setup a Ruby in it and study for 2 weeks. I have been developing applications in windows and Linux is not my cup of tea. Some part of me wants to try out Linux but I want to first convince myself whether OS really matters for Ruby development. If Linux does matter, which distribution can I start looking at? Please advise.

  Read the article

• NoMethodError: undefined method `has_attached_file'

  - by mirza

  Paperclip produces this error, after checking out the plugin's rails3 branch. My Gemfile has following line: gem 'paperclip', :git => 'http://github.com/thoughtbot/paperclip.git', :branch => 'rails3' And the error message is: NoMethodError: undefined method `has_attached_file' for #<Class:0x2a50530>

  Read the article

< Previous Page | 27 28 29 30 31 32 33 34 35 36 37 38  | Next Page >