One of the numerous niceties of Ruby is the possibility to extend existing classes with your own methods. That’s called “class reopening” or monkey-patching (the meaning of the latter can vary, though). So, take a look here: car = {:make => “bmw”, :year => “2003”} # => {:make=>”bmw”, :year=>”2003″} car.to_json # NoMethodError: undefined method `to_json’ … Read more
Important: Make sure your app is not using I18n 0.6.8, it has a bug that prevents the configuration to be set correctly. Short answer In order to silence the warning edit the application.rb file and include the following line inside the Rails::Application body config.i18n.enforce_available_locales = true The possible values are: false: if you want to … Read more
Rather than referring to the literal name of the class, inside an instance method you can just call self.class.whatever. class Foo def self.some_class_method puts self end def some_instance_method self.class.some_class_method end end print “Class method: ” Foo.some_class_method print “Instance method: ” Foo.new.some_instance_method Outputs: Class method: Foo Instance method: Foo
This will iterate through all the elements: array = [1, 2, 3, 4, 5, 6] array.each { |x| puts x } # Output: 1 2 3 4 5 6 This will iterate through all the elements giving you the value and the index: array = [“A”, “B”, “C”] array.each_with_index {|val, index| puts “#{val} => #{index}” … Read more
You can do that in several ways: As you shown with << but that is not the usual way With string interpolation source = “#{ROOT_DIR}/#{project}/App.config” with + source = “#{ROOT_DIR}/” + project + “/App.config” The second method seems to be more efficient in term of memory/speed from what I’ve seen (not measured though). All three … Read more
<% %> Executes the ruby code within the brackets. <%= %> Prints something into erb file. <%== %> Equivalent to <%= raw %>. Prints something verbatim (i.e. w/o escaping) into erb file. (Taken from Ruby on Rails Guides.) <% -%> Avoids line break after expression. <%# %> Comments out code within brackets; not sent to … Read more
I think I’ve figured it out: a = [3, 2, 4, 6, 3, 8] a.delete(3) #=> 3 a #=> [2, 4, 6, 8]
system The system method calls a system program. You have to provide the command as a string argument to this method. For example: >> system(“date”) Wed Sep 4 22:03:44 CEST 2013 => true The invoked program will use the current STDIN, STDOUT and STDERR objects of your Ruby program. In fact, the actual return value … Read more
# remove all old versions of the gem gem cleanup rjb # choose which ones you want to remove gem uninstall rjb # remove version 1.1.9 only gem uninstall rjb –version 1.1.9 # remove all versions less than 1.3.4 gem uninstall rjb –version ‘<1.3.4’
I believe what you are looking for is assign_attributes. It’s basically the same as update_attributes but it doesn’t save the record: class User < ActiveRecord::Base attr_accessible :name attr_accessible :name, :is_admin, :as => :admin end user = User.new user.assign_attributes({ :name => ‘Josh’, :is_admin => true }) # Raises an ActiveModel::MassAssignmentSecurity::Error user.assign_attributes({ :name => ‘Bob’}) user.name # … Read more