42 » Rails

Rails find case sensitive search

kosmas — Mon, 17 May 2010 16:14:48 +0000

Problem
You want to use find in Rails for a case sensitive search. For example in your authentication logic you have something to find the user to login as in:
u=User.find_by_login(‘username’)
If you don’t want to limit the available logins with case insensitive validation in the model, then the above code will not work if you have ‘Username’ and ‘username’ as available logins, as the find will only return one of them.

Solution
Change the find method to use the BINARY keyword in your database (only used with MySQL), as in the following:
u=User.find(:first, :conditions => ["BINARY login = ?", login])

NoMethodError (undefined method `refresh_token’ for #):

kosmas — Fri, 26 Mar 2010 15:52:48 +0000

Problem
When you get the above error you cannot login to your application.

Solution
You will need to delete the cookies for the authentication, so in Firefox (Linux) go to Preferences, remove individual cookies for the specific domain.

Freezing rails to an older version using gems

kosmas — Mon, 15 Mar 2010 10:43:45 +0000

Problem
You want to deploy to a shared host (dreamhost) that has a later version of rails from the one you have developed your application.
You also have a later version installed in your development pc,and using rake rails:freeze:gems uses the latest one and not the one you want.

Solution
Use the following to freeze the specific version you want, and by using your gems you have installed:
rake rails:freeze:gems VERSION=2.3.2

Freezing gems (other than rails) on 2.3.4

kosmas — Tue, 08 Sep 2009 20:17:04 +0000

Problem
Your host (ie dreamhost) for deploying applications doesn’t have the gems you are using in your development.

Solution
After freezing your rails gems with rake rails:freeze:gems, freeze the rest of your gems, not with rake gems:freeze gem=GEM_NAME, as used in previous versions of rails, but with:

rake gems:unpack

Rails XSS vulnerability

kosmas — Fri, 04 Sep 2009 12:39:16 +0000

Problem
There was a warning about an XSS vulnerability in Ruby on Rails. More details can be found here.

Solution
Upgrade to the most recent (fixed) Rails version (2.3.4):

sudo gem install rails

Phusion Passenger installation in Mandriva 2009

kosmas — Thu, 08 Jan 2009 11:30:53 +0000

Problem
You have recently installed Mandriva 2009 and you want to install phusion passenger.

Solution

First make sure that apache is installed. If it is not installed (default), do:
```
urpmi apache
```
On the selection question about the dependencies select option 1 (apache-prefork)
Use the details from the phusion passenger website. ie:
Install passenger:
```
gem install passenger
```
Run the passenger installation:
```
passenger-install-apache2-module
```
If at the second stage of the installation the installer complains that GNU C++ compiler … not found, install the gnu c++ compiler, with:
```
urpmi gcc_c++
```
Run the passenger installation (step 3) again. If at this stage the installer complains that Apache 2 development headers … not found, use:
```
urpmi apache-devel
```
Run passenger installer (step 3), once more. Now everything should be ok and the apache 2 module will be installed when the installer finishes.
Restart the Apache webserver, and you should be able to add your Rails application. Use the following to deploy your application in /somewhere/public:
```
  ServerName www.yourhost.com
  DocumentRoot /somewhere/public
```

assert_difference and Rails 2.1.0

kosmas — Tue, 25 Nov 2008 13:50:17 +0000

Problem
Trying to use the assert_difference with Rails 2.1.0 produces errors if trying to use it with the syntax of another rails version.

Solution
The correct syntax for using assert_difference with rails 2.1.0 is:

def test_should_create_user

assert_difference(User, :count, 1) do

user = create_user

assert !user.new_record?, "#{user.errors.full_messages.to_sentence}"

end

end

Rails 2 new ways

kosmas — Wed, 28 May 2008 12:21:28 +0000

Problem
To get used to the new ways of working with Rails 2.

Solution
Here are some of the new ways of doing things in Rails 2.

Create a scaffold and migration on one step:
```
./script/generate scaffold product fied1_name:string field2_name:string field3_name:float
```
Make sure that you don’t have any previous migration(ie manually created) for the same model, as the generator will stop and won’t overwrite the previous migration.