Tue 21 Feb 2012
Posted by kosmas under linux
No Comments
Problem
You have multiple scanned images as pnm files, and you would like to convert them to a single pdf file.
Solution
If you have imagemagick installed you should be able to use the convert as follows to combine the images to one pdf file:
convert image1.pnm image2.pnm image3.pnm output.pdf
Mon 20 Feb 2012
Posted by kosmas under ruby on rails
No Comments
Problem
You would like to get access to the facebook app_id or secret_id in your Rails application.
Solution
You can use the following in your console/app:
Devise.omniauth_configs[:facebook].args[0]
Wed 8 Feb 2012
Posted by kosmas under Redmine
No Comments
Problem
You get the following error in redmine when trying to update a task that has a parent task.
Parent task translation missing: en, activerecord, errors, models, issue, attributes, parent_issue_id, not_a_valid_parent
Solution
It seems that for some reason when you add more than one subtask, the lft and rgt id numbers are not created correctly so you cannot update the subtasks.
If the numbers are overlapping (rgt for first subtask 2 and lft for second subtask 2), then there is a problem.
So in order to be able to solve that you will need to change the lft, rgt ids to have subsequent numbers as:
first subtask: lft -> 1 , rgt -> 2
second subtask: lft -> 3, rgt -> 4
Wed 8 Feb 2012
Posted by kosmas under ruby on rails, Ubuntu/Debian
No Comments
Problem
You would like to have an ERD diagram of your database in your Ruby on Rails project.
Solution
You can install the Rails ERD from here, and install it by following the instructions.
For Ubuntu/debian systems should be:
sudo apt-get install graphviz
and then adding the gem to your Gemfile in the development section as:
group :development do gem "rails-erd", "~> 0.4.5" end
You can then run bundle install to install the gem and rake erb to create the diagram pdf.
Wed 1 Feb 2012
Posted by kosmas under Cucumber, ruby on rails
No Comments
Problem
You want to be able to go through a scenario step by step when you are testing with a browser as sometimes can be very fast.
Solution
By following the suggestion here you would only need to add the following to your features/support/hooks.rb file
AfterStep('@pause') do
print "Press Return to continue ..."
STDIN.getc
end
and then you should be able to use it in your scenario by adding the @pause tag.
Then you would have to press continue in your terminal to go step by step
Tue 31 Jan 2012
Posted by kosmas under Ruby, ruby on rails
No Comments
Problem
You want to be able to use different gems/rails version for your application after installing the latest rails version, without having to use bundle exec.
Solution
You can use the named gemsets with rvm.
More instructions are here: http://beginrescueend.com/gemsets/basics/
so you can install two gemsets for example ruby-1.9.3-p0@rails3_0_11 and another with ruby-1.9.3-p0@rails3_2_1
you could then do :
rvm gemset create rails3_0_11 rails3_2_1 rvm 1.9.3-p0@rails3_0_11 gem install rails -v 3.0.11 rvm 1.9.3-p0@rails3_2_1 gem install rails -v 3.2.1 rvm gemset use rails3_0_11 bundle install
Mon 9 Jan 2012
Posted by kosmas under linux, ruby on rails
No Comments
Problem
If you have setup guard with your Rails project and you are trying to run it in an (K)Ubuntu installation you get the following message:
Could not open library 'libgtkmm-2.4.so': libgtkmm-2.4.so: cannot open shared object file: No such file or directory.
Solution
Install the missing library with the following:
sudo apt-get install libgtkmm-2.4
Thu 22 Dec 2011
Posted by kosmas under linux, ruby on rails
No Comments
Problem
You want to use the rmagick gem in your rails application after a new (K)ubuntu system installation, but the bundler command gives you errors.
Solution
Install the following before running budler again:
sudo apt-get install imagemagick libmagickcore-dev libmagickwand-dev
Tue 13 Dec 2011
Posted by kosmas under Cucumber, Ruby
No Comments
Problem
You would like to test the carrierwave imageuploader with a cucumber test, but you would also like to use a generic step that can be used with different classes and different image file column names.
Solution
Use the following and perhaps put it a file named features/common_steps.rb
Then /^the url for the column "([^"]*)" of model "([^"]*)" should be "([^"]*)"$/ do |col,mdl,url| # First get tne class name from the mdl argument by using the Kernel.const_get method m = Kernel.const_get(mdl).first # And then use the send with the column name (col) to call the model's field, # the url method of ImageUploader to get the full path # and basename to get only the file name File.basename(m.send(col).url).should == url end
Mon 5 Dec 2011
Posted by kosmas under ruby on rails
No Comments
Problem
You have developed your application in your local environment or you use it in an environment that has your local timezone, but your live deployment server is in a hosted server that has a different timezone. So a lot of the SQL queries, are not working correctly.
Solution
Login as root in your server and run:
dpkg-reconfigure tzdata
and then reload your database server.