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Problem
You want to do a new installation of Aptana RadRails IDE in Mandriva as an eclipse plugin.

Solution

• Install eclipse first (selecting openjdk when prompted):

  sudo urpmi eclipse

• According to the instructions here take the following steps:
• From the Help menu in Eclipse, select Software Updates
• Select the Available Sotware tab
• Click the “Add Site..” button.
• Specify the Location Url update site: http://update.aptana.com/update/studio/3.4/ and click OK
• Select the checkbox next to the added update site.
• Click the install button.
• Complete instruction to install from update site and restart eclipse
• Go to ‘My Aptana’ page and then the ‘Plugins’ tab on the top
• Click on Aptana Rad Rails ‘Get It’ link and get through the next sequence of screens select ‘ok’.
• Restart Eclipse and RadRails should now be installed.

Problem
When using a nested (or embedded) scaffold in ActiveScaffold with Rails 2.3.2 you have the error:

undefined method `render_component'

Solution
According to the issue here, in Rails 2.3 the render_component has been removed.

Install the render_component from:

script/plugin install git://github.com/lackac/render_component.git -r rails-edge

and restart your server, and it should be working.

Problem
While developing on Rails 2.3.2 you want to deploy in dreamhost that uses 2.2.2 at the moment.

Solution
Although we could try to freeze the specific rails version we are using, it’s probably easier as a temporary solution, until dreamhost upgrades the rails version to do the following:

• Make sure that we have the following line with the appropriate version of

RAILS_GEM_VERSION = '2.2.2' unless defined? RAILS_GEM_VERSION

in the config/environment.rb file

• Rename the application_controller.rb file back to application.rb
• Comment out the following line from config/environments/production.rb

config.action_view.cache_template_loading = true

 

Problem
There is a DoS vulnerability in Ruby, and consequently in Ruby on Rails, reported by Jose Fernandez

Solution
For anyone that haven’t so far looked into it there are some links to resolve the problem:

Ruby site

The link below also includes an example script (example.rb) to see if your version of Ruby is vulnerable:
NZKoz fix

Problem
After upgrading to Mandriva 2009.1 Spring, that uses KDE 4, you can no longer lock the screen as you get the error:

no appropriate greeter plugin...

Solution
There is a package missing from the upgrade so do:

urpmi kdm

Problem
You are trying to install spree from the git source, following the instructions from here, but there are errors like:

gem install activemerchant --version "= 1.4.1"
ERROR:  While generating documentation for builder-2.1.2
... MESSAGE:   Unhandled special: Special: type=17, text=""
... RDOC args: --ri --op /usr/lib/ruby/gems/1.8/doc/builder-2.1.2/ri --title Builder
    -- Easy XML Building --main README --line-numbers
    --quiet lib CHANGES Rakefile README doc/releases/builder-1.2.4.rdoc
    doc/releases/builder-2.0.0.rdoc doc/releases/builder-2.1.1.

Solution
Make sure you have the following gems installed:

sudo gem install builder haml echoe

and then run:

sudo rake gems:install

Problem
You are trying to install the mysql gem in Mandriva, but it fails with error messages:

ERROR:  Error installing mysql:
ERROR: Failed to build gem native extension...
checking for mysql_query() in -lmysclient... no ....

Solution
After searching in google, with solutions about providing different options (– –with-mysql-config, ..etc), even trying different combinations for providing the client library path, the configuration file, or the header file path, was still faced with the same error installing the mysql gem.
As the Mandriva installation was quite new, it turns out to be a couple of missing packages.
So try:

urpmi gcc
urpmi make

and run:

gem install mysql

again.

It should work out ok install the gem and output:

Building native extensions. This could take a while...
Successfully installed mysql-2.7
1 gem installed

Problem
Upgrading from a previous version of Rails to the latest 2.3.2, you get an error:

NameError: uninitialized constant ApplicationController

both in the web browser and in console.

Solution
Since the introduction of Rails 2.3 the application.rb file has been renamed to application_controller.rb.
So in order to solve the problem just rename your file application.rb to application_controller.rb.

Thanks to the post here

Problem
You want to use ActiveScaffold in Rails 2.2, in a model that you have created using the standard Rails scaffolding script.

Solution

1. Install the ActiveScaffold plugin:

   script/plugin install git://github.com/activescaffold/active_scaffold.git -r rails-2.2

2. In your layout (model or application for all models) add the following:

   <%= javascript_include_tag :defaults %>
   <%= active_scaffold_includes %>

3. In your controller file delete all the standard scaffolding code and add one line, so that your new controller should look like:

   class SomethingsController < ApplicationController
     active_scaffold :something
   end

4. To configure a RESTful scaffold add the following to your route.rb file:

   map.resources :somethings, :active_scaffold => true

5. Delete the views that were created from the standard rails scaffolding in the views/somethings folder (edit, show, index ...)
6. Restart your server

You should now have an active scaffold for your model.

Problem
You have two big tables in MySQL (>640K records), that maybe differ in the number of fields, but you want to make sure that the data in the common fields in both tables are the same.

Solution

1. Use mysql to export the data from the first table in a csv file, selecting only the common fields.
   We use the /tmp folder on the server to make sure we have the right permissions to create the file:

   mysql>SELECT common_field1, common_field2, ...
   INTO OUTFILE '/tmp/first_table.txt'
   FIELDS TERMINATED BY ','
   OPTIONALLY ENCLOSED BY '"'
   LINES TERMINATED BY '\n'
   FROM table1;

2. If the tables are in different databases remember to switch db:

   use seconddb;

   Export the second table in the second file:

   mysql>SELECT common_field1, common_field2, ...
   INTO OUTFILE '/tmp/second_table.txt'
   FIELDS TERMINATED BY ','
   OPTIONALLY ENCLOSED BY '"'
   LINES TERMINATED BY '\n'
   FROM table2;

3. now use the diff. You can use any of the following options:
   • diff -q first_table.txt second_table.txt
   • diff first_table.txt second_table.txt > diff.txt