Wednesday, December 30, 2009
Don't use return statement in call block
Following code snippet describes it with example.
def function1(&block)
callback_result = yield('value1', 'value2')
puts "call block returned: #{callback_result}"
end
def function2()
function1() do |param1, param2|
puts "block implementation of function2 with param1 => #{param1} & param2 => #{param2}"
return "#{param1} changed. #{param2} changed."
end
puts "next line after calling function1"
return "function2 returned"
end
def function3()
function1() do |param1, param2|
puts "block implementation of function3 with param1 => #{param1} & param2 => #{param2}"
"#{param1} changed. #{param2} changed."
end
puts "next line after calling function1"
return "function3 returned"
end
output of function2() is
block implementation of function2 with param1 => value1 & param2 => value2
"value1 changed. value2 changed."
Output of function3() is
block implementation of function3 with param1 => value1 & param2 => value2
call block returned: value1 changed. value2 changed.
next line after calling function1
"function3 returned"
Tuesday, April 28, 2009
Layout in actionmailer
If mailer class is like
class UserMailer < ActionMailer::Base
def welcome_mail()
....
end
....
end
then the mailer layout name will be user_mailer.html.erb in view/layouts directory. The layout name needs to end in “_mailer” to be automatically recognized by mailer as a layout.
Content of user_mailer.html.erb should contain yield like the application layout. In this example the welcome_mail.html.erb will be rendered at yield position.
A different layout can also be set using
layout 'awesome' # it will use awesome.html.erb as the layout
class UserMailer < ActionMailer::Base
layout 'awesome'
....
end
Resource: http://guides.rubyonrails.org/action_mailer_basics.html
Wednesday, April 22, 2009
Error in loading mysql library in rails
Error in loading mysql library
The specified module could not be found. - C:/ruby/lib/ruby/gems/1.8/gems/mysql-2.7.3-x86-mswin32/ext/mysql.so
Solution:
For this to work, you must have libmysql.dll in your PATH environmental variable. If you have MySQL installed locally,
just make sure that
install one or more of the MySQL tools, find the libmysql.dll included in their bin directory, and copy it to
the %SystemRoot%\System32 folder.
Reference: RubyInstallDirectory/lib/ruby/gems/1.8/gems/mysql-2.7.3-x86-mswin32/README
Saturday, January 10, 2009
Access a method from both view and controller
If you need a method that will be accessed from both view and controller write the method in controller and pass the name of the function as an argument of helper_method.
class ApplicationController < ActionController::Base
..
..
def logged_in_user()
user_id = session[:user_id]
user = User.find_by_id(user_id)
return user
end
helper_method :logged_in_user
end
Here, logged_in_user method is accessible from all of the controllers those extend ApplicationController and helper_method :logged_in_user will expose this method to views. Your common accessible method signature may have arguments. But, only helper_method :logged_in_user is enough to make it accessible from view with the same signature defined.
Sunday, November 30, 2008
linux password
passwd sleepy Change sleepy's password.
passwd -d sleepy Delete sleepy's password.
reference