Ruby on Rails Planet

Gem 1.5 with Rails 2.3 »

Created at: 19.03.2011 11:48, source: Ruby Rockers, tagged: Solutions gem rails ruby Solutions

You may fall down into the situation where you don’t have RVM and your system gem is upgraded for using latest things.

And your old application is still running on older version of rails.

This is just a workaround of using Gem > 1.3.7 in Rails 2.3 Applications.

I have tested this solution with Rails 2.3.5 and different version of gems.

After upgrading gems to 1.6.2 i have got an error

/activesupport-2.3.5/lib/active_support/dependencies.rb:55:
uninitialized constant ActiveSupport::Dependencies::Mutex (NameError)

To fix this error need to update boot.rb file. Place this at the top of boot.rb

require 'thread'

After adding this you should be getting this error

/gem_dependency.rb:119:in
 `requirement': undefined local variable or method `version_requirements'

To fix this error you need update your environment.rb file.
Add this code above your Rails::Initializer.run block.

if Gem::Version.new(Gem::VERSION) >= Gem::Version.new('1.3.7')
 module Rails
   class GemDependency
     def requirement
       r = super
       (r == Gem::Requirement.default) ? nil : r
     end
   end
 end
end

Now your application should start running properly. Have fun

Now you can downgrade or upgrade your system gem version. Your application will still run.

Above workaround works for me very well. Any other ideas?

Redis key-value store »

Created at: 18.03.2011 21:55, source: Ruby Rockers, tagged: Technology gem redis ruby store

Redis is really cool and lightweight key-value store. If you are looking for something in which you can store some string, hashes, lists, sets. The Redis is the best.

If you are a Ruby developer then you must try out this with a redis-rb gem. Very easy to configure, very easy to store things.

Following is the way of using redis in Ruby way.

To install

gem install redis

To load

require 'redis'

Before performing any operation with redis server you need to install Redis and start the redis server.

After that you can do like

redis = Redis.new # Automatically connect with the default port.

# if you have changed the port then you can specify the port in initialize.

>> redis.set "foo", "bar"
=> "OK"

>> redis.get "foo"
=> "bar"

Storing objects

>> redis.set "foo", [1, 2, 3].to_json
=> OK

>> JSON.parse(redis.get("foo"))
=> [1, 2, 3]

There are lot’s more things you can do with the Redis.

Links help you in redis

Redis official documentation (http://redis.io)
Github redis repository (https://github.com/antirez/redis)
Github redis rubygem repository (https://github.com/ezmobius/redis-rb)

Flash Message Conductor now a Gem »

Created at: 13.10.2009 18:30, source: Robby on Rails, tagged: Ruby on Rails PLANET ARGON gem plugins github development code rubyonrails

We’ve been doing some early (or late… if you’re a half-full kind of person) spring cleaning on some of our projects. One of the small projects, flash_message_conductor, which we released last year as a plugin is now a gem. We’ve been moving away from using plugins in favor of gems as we like locking in specific released versions and being able to specify them in our environment.rb file is quite convenient.

To install, just run the following:


  sudo gem install flash-message-conductor --source=http://gemcutter.org
  Successfully installed flash-message-conductor-1.0.0
  1 gem installed
  Installing ri documentation for flash-message-conductor-1.0.0...
  Installing RDoc documentation for flash-message-conductor-1.0.0...

You’ll then just need to include the following in your config/environment.rb file.

Rails::Initializer.run do |config|
  # ...
  config.gem 'flash-message-conductor', :lib => 'flash_message_conductor', :source => "http://gemcutter.org"
end

You can take a peak at the README for usage examples.

We’ll be packaging up a handful of our various plugins that we reuse on projects and moving them to gems. Stay tuned… :-)

Weird Gem Error »

Created at: 10.08.2009 09:21, source: Rail Spikes - Home, tagged: gem

Talk about a hard problem to diagnose!

I canceled the installation of Rack 1.0 half way through because I realized I was running the wrong command (I didn’t use sudo like I wanted to).

After that, I couldn’t load rack at all, even though I could see it in my gems directory and I could load other gems there. I got a LoadError, like this:

irb(main):001:0> require 'rubygems'
=> true
irb(main):002:0> require 'rack'
LoadError: no such file to load -- rack
from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
from (irb):2

I tried downgrading Rails to the version that used Rack 0.9.1 and then I got an error saying Rails couldn’t activate Rack 0.9.1 because 1.0.0 was already active!

Finally figured it out—there was a gemspec for rack-1.0.0 in my ~/.gems directory, but no corresponding gem in the lib directory. Ugh!

Get to know a gem: Ghost »

Created at: 12.01.2009 08:18, source: Robby on Rails, tagged: Ruby on Rails ruby programming gem ghost dns development rubygems ruby

In my last post, Subdomain accounts with Ruby on Rails explaind, I mentioned that you’d need to modify your /etc/hosts file to use custom subdomains for development/testing. Apparently, there is a much better way to handle this that I was introduced to by Nathan de Vries. Nathan suggests using a gem that I hadn’t heard of before that bares the name of Ghost (view project on github).

Ghost describes itself as…

“A gem that allows you to create, list, and modify local hostnames in 10.5 with ease…”—

If you’ve ever had to modify your /etc/hosts file for anything local, I highly encourage you to check out this shiny gem.

Installing Ghost

Like most gems, you can just install Ghost with the following command.


~ : sudo gem install ghost
Password:
Successfully installed ghost-0.1.2-universal-darwin-9
1 gem installed
Installing ri documentation for ghost-0.1.2-universal-darwin-9...
Installing RDoc documentation for ghost-0.1.2-universal-darwin-9...

Okay, now that Ghost is installed, let’s see what we can do with it.

Using Ghost for local domains/subdomains

Ghost is fairly straight forward. It’s essentially a friendly wrapper for dscl, which is the Directory Service command line utility for Mac OS X. I’ve never played with that directly, but it seems that with Ghost… I shouldn’t need to. :-)

With Ghost, you can add, modify, and delete entries in the Directory Service by issuing any of the following commands. Let’s start out by running ghost to see what we have here.


 ~ : ghost
USAGE: ghost add <hostname> [<ip=127.0.1.1>]
       ghost modify <hostname> <ip>
       ghost delete <hostname>
       ghost list
       ghost empty

Okay, let’s see if there is anything already listed.


   ~ : ghost list
  Listing 0 host(s):

Nope. Let’s test this out. First, we’ll try to ping a domain name that we hope doesn’t exist.


   ~ : ping bigbrown.cow
  ping: cannot resolve bigbrown.cow: Unknown host

Alright, now we’ll add bigbrown.cow with ghost.


   ~ : ghost add bigbrown.cow
  Password:
    [Adding] bigbrown.cow -> 127.0.0.1

As you can see, it required root credentials to do this as it’s system-wide. Let’s now see if we can talk to bigbrown.cow.


   ~ : ping bigbrown.cow     
  PING bigbrown.cow (127.0.0.1): 56 data bytes
  64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.047 ms
  64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.035 ms
  ^C
  --- bigbrown.cow ping statistics ---
  2 packets transmitted, 2 packets received, 0% packet loss
  round-trip min/avg/max/stddev = 0.035/0.041/0.047/0.006 ms

Excellent! If we run ghost list again, we should see this record.


~ : ghost list
Listing 1 host(s):
  bigbrown.cow -> 127.0.0.1

We can modify the record to a non-localhost IP as well with ghost modify.


   ~ : ghost modify bigbrown.cow 192.168.10.104
    [Modifying] bigbrown.cow -> 192.168.10.104
   ~ : ghost list
  Listing 1 host(s):
    bigbrown.cow -> 192.168.10.104

I’ll let you play with it yourself as there isn’t much to it. This is a great little addition to my development environment. Thanks to Nathan for pointing it out and to Bodaniel Jeanes for creating this useful gem.