2. create your local git repository (git init)

3. get a free heroku.com account

4. install the heroku gem (gem install heroku)

5. add your files (git add .)

6. commit your files (git commit -m „my new app“)

7. create your app @ heroku (heroku create) –> public key needed!

8. push your app to heroku (git push heroku master)

9. check the output (heroku logs)

10. add needed gems (create a .gems file in your folder and add it to the repository, each gem a new line e.g. hpricot)

11. get more Infos @ heroku (http://docs.heroku.com/)

undefined method self_and_descendants_from_active_record for Cart:Class

Our Cart class has no ActiveRecord binding, but we need some validations, so we simple use

@errors = ActiveRecord::Errors.new(self)

and overerride the valid? action.

But now we get the undefined method error.

Solution

Implement in your class also:

 def self.self_and_descendants_from_active_record
    [self]
  end

  def self.human_name(options = {})
    defaults = self_and_descendants_from_active_record.map do |klass|
      :"#{klass.name.underscore}"
    end
    defaults < [:activerecord, :models], :count => 1, :default => defaults}.merge(options))
  end

  def self.human_attribute_name(attribute_key_name, options = {})
    defaults = self_and_descendants_from_active_record.map do |klass|
      :"#{klass.name.underscore}.#{attribute_key_name}"
    end
    defaults << options[:default] if options[:default]
    defaults.flatten!
    defaults < defaults, :scope => [:activerecord, :attributes]))
  end

and you can still use ActiveModel like validations

„This is my string javascriptvalue and so on …“

solution

'<%= T("This is my string ## and so on ...", :translate_string) %>'.sub(/##/, javascript_value);

i simple use javascript sub to replace ## with the javascript_value.

Im Moment bin ich noch am einrichten / konfigurieren / Programme suchen, aber alles in allem ist es doch schön eine voll funktionsfähige Konsole zur Verfügung zu haben und den komfort einer schönen Oberfläche.

Allen Rails Entwicklern sei der folgende Artikel ans Herz gelegt:
http://giantrobots.thoughtbot.com/2009/3/30/2009-rubyist-guide-mac-os-x-development-environment
(Achtung: MySQL auch wirklich in der 32 Bit Version installieren!)

Als IDE empfehle ich Netbeans in der Version 6.7, auch wenn sich diese noch im Beta Stadium befindet.

So, und nun begebe ich mich noch auf die Suche nach einem einfachen Bildbearbeitungsprogramm

Stopping httpd: [FAILED]
Starting httpd: httpd: Syntax error on line 1of /etc/httpd/conf/
rails.conf: Cannot load /opt/ruby-enterprise/lib/ruby/gems/1.8/gems/
passenger-2.1.2/ext/apache2/mod_passenger.so into server: /opt/ruby-
enterprise/lib/ruby/gems/1.8/gems/passenger-2.1.2/ext/apache2/
mod_passenger.so: failed to map segment from shared object: Permission
denied [FAILED]

Solution:
Disable SELinux, or have a closer look to the docs.

Without many words, i hope the code speaks for itself.
Take care of the :tag attriubte in the helper (default is li) and the container has to be the tbody.

Open Source Stack = $0

Because Rails runs on the JVM (JRuby), it is platform agnostic and capable of running on top of a 100% open source stack. Everything including the OS, app server, and database may be obtained free of charge with no license fees.

Faster Development Time

Yes, it’s great that everything needed to run Rails’ applications may be obtained for free, but what’s even a bigger cost savings is how much time developers can save by working within the JRuby/Rails environment. Rails really tends to speed up development in the following 3 areas:

Data Access

ActiveRecord provides an amazingly efficient way to model domain objects as well as persist them to a database.

Scaffolding

Scaffolding speeds up development time rapidly.

Syntax

When working with JRuby and Rails, developers will find themselves writing less code than when working within the traditional Java environment. Less code translates into shorter development time.

Summary

Rails is a great fit for a recession. It allows developers to create high quality applications on top of a free open source stack in less time than many of the more common, corporate frameworks.

Funktioniert mit JRuby 1.2 RC1, also fröhliches testen.

I installed VirtualBox (virtualbox.org) and setup CentOS, for this i downloaded the complete image at http://virtualbox.wordpress.com/images/centos/ (remember to copy the root password for the first login)

To start setup:
- change root password
- add an additional user
- update system files (yum update)
- install mysql (to use with ruby mysql gem you need to install also the developer packages)
- install ruby-enterprise (setup .bashrc)
- install subversion (yum install subversion)

Some useful infos:

Install Ruby Enterprise (including Rails):
Installing Ruby Enterprise on CentOS 5.2

Install MySQL Gem
Faild for me, so i found here the solution:
mysql gem on centos
Update: More Infos: Mysql gem centos5 hell

German Keyboard Layout
To change temporary (until reboot)
loadkeys de-latin1
And to verify that the keyboard layout is correct use the command: showkey

Permanent setting (CentOS):
Edit /etc/sysconfig/keyboard and replace KEYTABLE=“us“ by KEYTABLE=“de-latin1″
save and reboot.

To find whitch keyboard layout maps that is available is in the map
/lib/kbd/keymaps/i386/…depending on which distro is used.

Enable high resolution console:
As root, edit the file ‘/etc/grub.conf’, and add ‘vga=XXX’ to the line that begins with kernel.
Get other values here: VGA Screen Resolution

I will update this post, but for now i dont remember more steps

JRuby vs. WAS:

First we simple create an war file (warbler) and try to deploy it on WAS, and run in a 100% CPU load.
After some use of google we mention that we have to install the latest Fixpack (Current 6.1.0.15, Latest 6.1.0.19) this takes a while (about 500 MB to download and about 1 hour for install).

Second try, app is not loading, so we notice to optimize our web.xml (change from filter to servlet)

Last try, deploying works like it should (10 seconds). Navigation to the URL of our App, next Error.
A look in the log files shows us some cryptic „java.lang.ClassFormatError“.

Conclusion:

We were able to deploy and run our application in IBM WebSphere, but we will not use it for now. Watching JRuby Issue Tracking, Bug: 3015.

Update:

The Bug is fixed, so its time to check the deploymet again.