#ruby-on-rails-3

Fix: Rails – Could not find a JavaScript runtime? #development #fix #answer

Rails – Could not find a JavaScript runtime?

I created a new Rails project using rails 3.1.0.rc4 on my local machine but when I try to start the server I get: Could not find a JavaScript runtime. See here for a list of available runtimes. (ExecJS::RuntimeUnavailable)

Note: This is not about Heroku.

Answer [by Gazler]: Rails – Could not find a JavaScript runtime?

Note from Michael 12/28/2011 – I…

How-to: Rails update_attributes without save? #dev #fix #computers

Rails update_attributes without save?

Is there an alternative to update_attributes that does not save the record?

So I could do something like:

@car = Car.new(:make => 'GMC') #other processing @car.update_attributes(:model => 'Sierra', :year => "2012", :looks => "Super Sexy, wanna make love to it") #other processing @car.save

BTW, I know I can @car.model = 'Sierra', but I want to update them…

How-to: How to remove a key from Hash and get the remaining hash in Ruby/Rails? #fix #dev #computers

How to remove a key from Hash and get the remaining hash in Ruby/Rails?

To add a new pair to Hash I do:

{:a => 1, :b => 2}.merge!({:c => 3}) # => {:a=>1, :b=>2, :c=>3}

Is there a similar way to delete a key from Hash ?

This works:

{:a => 1, :b => 2}.reject!{ |k| k == :a } # => {:b=>2}

but I would expect to have something like:

{:a => 1, :b => 2}.delete!(:a) # => {:b=>2}

It is important that…

Fix: rmagick gem install "Can't find Magick-config" #programming #answer #it

rmagick gem install "Can’t find Magick-config"

I get the error shown below when attempting to install the rmagick gem. I am on Snowleopard 10.6 using RVM, Ruby 1.9.2-head and Rails 3.05. Responses to similar questions recommended installing ImageMagick, which I successfully did. Other suggested installing the “libmagick9-dev library”, however, I can not figure out how to do this.

I’m a new…

Solution: Rails DB Migration – How To Drop a Table? #fix #answer #dev

Rails DB Migration – How To Drop a Table?

I added a table that I thought I was going to need, but now no longer plan on using it. How should I remove that table?

I’ve already ran migrations, so the table is in my database. I figure rails generate migration should be able to handle this, but I haven’t figured out how yet.

I’ve tried rails generate migration drop_tablename, but that just generated…

Solution: Global access to Rake DSL methods is deprecated #computers #programming #fix

Global access to Rake DSL methods is deprecated

I am working through the Ruby on Rails 3 tutorial book and typed the following on the command line:

rake db:migrate

which produced the following warning.

WARNING: Global access to Rake DSL methods is deprecated. Please Include ... Rake::DSL into classes and modules which use the Rake DSL methods. WARNING: DSL method DemoApp::Application#task…

How to: Remove ActiveRecord in Rails 3

Remove ActiveRecord in Rails 3

Now that Rails 3 beta is out, I thought I’d have a look at rewriting an app I have just started work on in Rails 3 beta, both to get a feel for it and get a bit of a head-start. The app uses MongoDB and MongoMapper for all of its models and therefore has no need for ActiveRecord. In the previous version, I am unloading activerecord in the following way:

config.fram…

Fixed Rails 3.1 and Image Assets #dev #it #asnwer

Rails 3.1 and Image Assets

I have put all my images for my admin theme in the assets folder within a folder called admin. Then I link to it like normal ie.

# Ruby image_tag "admin/file.jpg" ..... #CSS .logo{ background:url('/assets/images/admin/logo.png');

FYI. Just for testing I am not using the asset_path tag just yet as I have not compiled my assets.

Ok all good so far until I decided to…