How do I structure gem to avoid LoadError in my Rails project?

Rails
1

Hi,

I’m new to gem development. I just completed a gem for use with a Rails
3.0.7 project. The gem itself passes its tests. I’ve listed the gem in
the Rails project’s Gemfile…

Unfortunately, Rails is choking on some requires in my gem. Here is what
I get in Rails:

activesupport-3.0.7/lib/active_support/dependencies.rb:239:in `require’:
no such file to load – zip_code/config.rb (LoadError)

Meanwhile, the lib directory in the gem consists of zip_code.rb
and /zip_code, where zip_code.rb contains the key lines:

$LOAD_PATH.unshift(File.dirname(FILE))

require ‘zip_code/version.rb’
require ‘zip_code/config.rb’
require ‘zip_code/zip_code.rb’

Seems like Rails is stopping on config.rb and zip_code.rb – it doesn’t
see them.

Any tips on how to properly require files in a gem so that Rails will
see them?

Thanks,

Grar

2

Grary S. wrote in post #1019984:

Hi,

I’m new to gem development. I just completed a gem for use with a Rails
3.0.7 project. The gem itself passes its tests. I’ve listed the gem in
the Rails project’s Gemfile…

Unfortunately, Rails is choking on some requires in my gem. Here is what
I get in Rails:

activesupport-3.0.7/lib/active_support/dependencies.rb:239:in `require’:
no such file to load – zip_code/config.rb (LoadError)

$LOAD_PATH.unshift(File.dirname(FILE))

Try getting rid of that line. Do you have a .gemspec file?

3

Your directory structure works for me in rails 3.0.9, but I don’t know
if my .gemspec file is different than yours. This is your directory
structure:

/lib
zip_code.rb – require ‘zip_code/config.rb’
/zip_code
version.rb
config.rb
zip_code.rb

Even though that works for me, do you think it’s wise to use the file
name zip_code.rb again in the /zip_code directory?

4

On Sep 3, 8:05pm, Grary S. [email protected] wrote:

no such file to load – zip_code/config.rb (LoadError)

Do you have a valid gemspec in the root of your project?

$LOAD_PATH.unshift(File.dirname(FILE))

Don’t play with your $LOAD_PATH.

Any tips on how to properly require files in a gem so that Rails will
see them?

Take a look to RubyGems guides:

–
Luis L.

5

Luis,

Yes, the gemspec is as listed in my previous post…

Thanks for the reference to RubyGems doc, which I am reading now, in
hopes of solving this.

Meanwhile, I’m wondering if there’s interaction between rvm 1.9.2 and
this problem?

In this connection, I modified zipcode/config.rb as follows…

require_relative “zipcode/config.rb”

module Zipcode

Your code goes here…

end

But I get the same kind of error…

.rvm/gems/ruby-1.9.2-p290/gems/zipcode-0.0.1/lib/zipcode/config.rb
(LoadError)

Grar

6

Hey,

Still no joy.

I thought I’d follow 7stud’s example and recreate the gem structure to
see if I could load it after any reasonable modifications…

/lib
zipcode.rb – require ‘zipcode/config.rb’
/zipcode
version.rb
config.rb
cityandstate.rb

…where lib/zipcode.rb is…

require “zipcode/config.rb”

module Zipcode

Your code goes here…

end

I’ll leave my gemspec farther below – in case someone sees something
above right away – but I still get the kind kind of error when this gem
is installed in my Rails 3.0.7 app…

gems/activesupport-3.0.7/lib/active_support/dependencies.rb:239:in
require': no such file to load -- zipcode/config.rb (LoadError) ... ruby-1.9.2-p290/gems/zipcode-0.0.1/lib/zipcode.rb:1:in<top
(required)>’

I’m using rvm 1.9.2 and Bundler in my attempt to create my first working
gem…now here’s the gemspec…

-- encoding: utf-8 --

$:.push File.expand_path("…/lib", FILE)
require “zipcode/version”

Gem::Specification.new do |s|
s.name = “zipcode”
s.version = Zipcode::VERSION
s.authors = [“Grar”]
s.email = [“[email protected]”]
s.homepage = “”
s.summary = %q{Provides city and state pair and zip data, and vice
versa}
s.description = %q{Cities in states and their zip codes}

s.rubyforge_project = “zipcode”

s.files = git ls-files.split("\n")
s.test_files = git ls-files -- {test,spec,features}/*.split("\n")
s.executables = git ls-files -- bin/*.split("\n").map{ |f|
File.basename(f) }
s.require_paths = [“lib”]
end

Thanks,

G

7

OK, solved it.

Thanks to Luis’s reference to the original rubygems guide, I was able to
build a simple gem that worked with my Rails 3.0.7 project. So, I
realized there was something wrong with my use of bundler in creating
gems.

The problem was that I was not managing the gem’s development with git
after the initial automatic commit with gem bundler. Thus, when I
executed ‘git ls-files’ at the command line, I saw that new files, like
lib/zipcode/config.rb, were not being loaded to the gem specification’s
file list when gem bundler’s ‘rake install’ was executed.

I guess a useful takeaway from this is that Gem::Specification.files is
a vital part of the dependency loading for a gem…

Grar