I have this code:
puts require './item'
puts $"
class Light < Item
#code
end
Item class in item.rb:
require './v3d'
require './ray'
class Item
attr_accessor :pos
def initialize(pos)
#pos = pos
end
def check(pos, dir)
return nil
end
def normal(ray)
return nil
end
end
that when I run my program prints this output:
false
enumerator.so
thread.rb
rational.so
complex.so
/usr/lib/x86_64-linux-gnu/ruby/2.3.0/enc/encdb.so
/usr/lib/x86_64-linux-gnu/ruby/2.3.0/enc/trans/transdb.so
/usr/lib/ruby/2.3.0/unicode_normalize.rb
/usr/lib/x86_64-linux-gnu/ruby/2.3.0/rbconfig.rb
/usr/lib/ruby/2.3.0/rubygems/compatibility.rb
/usr/lib/ruby/2.3.0/rubygems/defaults.rb
/usr/lib/ruby/2.3.0/rubygems/deprecate.rb
/usr/lib/ruby/2.3.0/rubygems/errors.rb
/usr/lib/ruby/2.3.0/rubygems/version.rb
/usr/lib/ruby/2.3.0/rubygems/requirement.rb
/usr/lib/ruby/2.3.0/rubygems/platform.rb
/usr/lib/ruby/2.3.0/rubygems/basic_specification.rb
/usr/lib/ruby/2.3.0/rubygems/stub_specification.rb
/usr/lib/ruby/2.3.0/rubygems/util/list.rb
/usr/lib/x86_64-linux-gnu/ruby/2.3.0/stringio.so
/usr/lib/ruby/2.3.0/rubygems/specification.rb
/usr/lib/ruby/2.3.0/rubygems/exceptions.rb
/usr/lib/ruby/vendor_ruby/rubygems/defaults/operating_system.rb
/usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_gem.rb
/usr/lib/ruby/2.3.0/monitor.rb
/usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb
/usr/lib/ruby/2.3.0/rubygems.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/version.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/core_ext/name_error.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/levenshtein.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/jaro_winkler.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkable.rb
/usr/lib/ruby/2.3.0/delegate.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkers/name_error_checkers/class_name_checker.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkers/name_error_checkers/variable_name_checker.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkers/name_error_checkers.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkers/method_name_checker.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkers/null_checker.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/formatter.rb
/usr/lib/ruby/vendor_ruby/did_you_mean.rb
/home/<user>/Documents/ruby/ray/write_ppm.rb
/home/<user>/Documents/ruby/ray/v3d.rb
/home/<user>/Documents/ruby/ray/pixel.rb
/home/<user>/Documents/ruby/ray/image.rb
/home/<user>/Documents/ruby/ray/material.rb
then throws:
/home/<user>/Documents/ruby/ray/light.rb:4:in `<top (required)>': uninitialized constant Item (NameError)
When require './item' is called, there is no error AND it returns false. From my understanding of how require works, it seems that the program incorrectly thinks it does not need to load item.rb. Why does this happen and how can I fix it?
Edit: expanded on some code
As a generic answer, not related to op, but because I had a similar issue and was pointed here by search engines.
Basically require 'http' returned false while gem was not loaded.
I figured out that there is a http.rb file inside load path and it is being loaded instead of the standard gem. So double check there are no conflicting file names of ruby files under library load path and the gem name.
I solved the problem by totally rewriting my require statements for every file. What I think the problem was, was this:
item.rb contained require './ray'
ray.rb contained require './light'
light.rb contained require './item' and class Light < Item
While loading item.rb, the interpreter saw it needed to also load ray.rb and therefore light.rb. When it reached the require './item' inside light.rb, it returned false because it was in the process of loading that file. However, since it was not yet finished loading, it did not show up in $". The interpreter then needed access to the definition of the Item class to finish loading light.rb, but because it needed to finish loading light.rb to load item.rb, the interpreter thew a NameError.
I think you may want require_relative instead.
http://ruby-doc.org/core-2.4.0/Kernel.html#method-i-require_relative
vs
http://ruby-doc.org/core-2.4.0/Kernel.html#method-i-require
You are correct in saying that if require 'my_lib' returns false, then 'my_lib' has already been loaded. However this is different from saying that a MyLib class is defined. Does your item.rb define an Item class?
Also, it may be possible that Item is defined somewhere else in the namespace hierarchy. e.g. if your item.rb is in some_gem/item.rb, and you're calling require from some_gem/, it will load successfully, but the name of the class might be SomeGem::Item. In this case you wouldn't be able to access it directly from the root namespace.
Last thing I can think of is that the item.rb file is changing under, or otherwise has some very dynamic pieces that are confusing the interpreter.
I would think that the issue is one of these before thinking that require is somehow messing up.
Related
I'm trying to use pools in a project of mine that uses Celluloid. However, whenever I invoke the pool method on a class which includes Celluloid (thus receiving methods from Celluloid::ClassMethods) I consistently get the error:
NoMethodError: undefined method `services' for Celluloid:Module
router at /Users/my_username/.rvm/gems/jruby-9.0.5.0/gems/celluloid-supervision-0.20.6/lib/celluloid/supervision/deprecate/supervise.rb:54
supervise at /Users/my_username/.rvm/gems/jruby-9.0.5.0/gems/celluloid-supervision-0.20.6/lib/celluloid/supervision/deprecate/supervise.rb:6
pool at /Users/my_username/.rvm/gems/jruby-9.0.5.0/gems/celluloid-pool-0.20.5/lib/celluloid/supervision/container/behavior/pool.rb:13
<top> at celluloid_pool_test.rb:14
Specifically, this part seems to be the problem:
NoMethodError: undefined method `services' for Celluloid:Module
It tells me that the offending line is /Users/my_username/.rvm/gems/jruby-9.0.5.0/gems/celluloid-supervision-0.20.6/lib/celluloid/supervision/deprecate/supervise.rb:54. It turns out that line holds the code for the Celluloid::Supervision.router method:
def router(*_args)
# TODO: Actually route, based on :branch, if present; or else:
Celluloid.services ### this line is what causes the error
end
To make sure that the issue wasn't with my particular project, I grabbed a code sample from this article which utilizes pools and tried to run it:
require 'celluloid'
require 'mathn'
class PrimeWorker
include Celluloid
def prime(number)
if number.prime?
puts number
end
end
end
pool = PrimeWorker.pool
(2..1000).to_a.map do |i|
pool.prime! i
end
sleep 100
It failed with the exact same error as my project:
Finally, I ran a dead simple piece of code in IRB to see if pool is what triggers the error about services:
class Foo
include Celluloid
end
Foo.pool
Sure enough, I got the exact same error. It seems that there is a bug in Celluloid or that I'm not loading a dependency properly. However, I did require 'celluloid/supervision' in my attempts at solving this, to no avail. Am I doing something wrong on my end or is this a bug in Celluloid?
It seems that others have run into this issue before: https://github.com/celluloid/celluloid-pool/issues/10. I guess it has something to do with Celluloid.services being deprecated and not working in newer versions of Celluloid, so using require 'celluloid/current' rather than just require 'celluloid' seems to do the trick.
I'm using "therubyracer" in a model, and I'm requiring at the top of the model as so:
require 'v8'
class Thing
def self.ctx; ##ctx ||= V8::Context.new; end;
def self.eval(script); ctx.eval(script); end;
end
However, I intermittently get:
NameError - uninitialized constant Thing::V8:
/app/thing.rb:3:in `ctx'
When testing requests through a local Padrino server, apparently after I modify code in Thing. This is corrected by restarting the padrino server. I'm assuming requiring v8 somewhere else would fix this problem, wheres the correct place?
This looks like it might be caused by the Padrino reloader getting confused when it reloads your thing.rb file, causing Ruby to look for V8 in the Thing namespace.
Try explicitly specifying V8 is in the top level using the :: prefix:
def self.ctx; ##ctx ||= ::V8::Context.new; end;
You can put it wherever you want if you add it on the Gemfile. Did you added it?
Thanks!
I am getting this error While running this
LoadError: Expected /home/user/Desktop/Tripurari/myapp/app/models/host.rb to define Host##
But every thing on it's place. Can some one tell me what the exact problem is below method.
def self.check_all(keyword)
memo_mutex = Mutex.new
memo = {}
threads = []
name = keyword.keyword
SITES.each do |site_and_options|
threads << Thread.new do
#host = Host.find_or_create_by_name(site)
if keyword.unavailable_usernames.find_by_host_id(#host.id)
memo[#host.name] = true
else
memo[#host.name] = false
end
end
end
threads.each { |t| t.join }
memo
end
The issue is probably caused by the autoloader. If the Host class is not yet loaded when first entering the loop where you create a couple of new threads, it is autoloaded, i.e. Rails searches the loadpath for a file matching the naming conventions and requires it.
This process is not threadsave. In your case, as you are creating servral threads in quick succession, each trying to autoload the global class, you get race conditions and strange things happen. Basically, you have two options for tackling this:
You can explicitly load the model before starting your threads by using require 'host' before starting your loop.
Or you can set config.threadsave! in an initializer. This will (among other things) preload all your classes when starting your server. This is preferred as with this, you avoid a truckload of other difficult to debug concurrency issues. For more information about config.threadsafe!, please refer to the excellent article by Aaron Patterson arguing it should be removed altogether in Rails 4.
Assuming the code you've quoted above is in a model's .rb file, add require_relative "host" to the top of that file.
I've just started writing a reasonably straightforward site using sinatra. My problem is that I wanted to refactor the main app.rb file but am getting errors trying to access the url params.
In my get '/' action, Sinatra's looking at which params are set and then needs to do a few different things depending on what's in the url. Something like this.
class App < Sinatra::Application
...
get '/' do
if params['code1']
#network = 'code1'
mode code here
elsif params['called'] && params['mac']
#network = 'code2'
mode code here
elsif params['code3']
#network = 'code3'
mode code here
end
end
The problem is that I need to require a file that also uses the params.
I've put the following in the above code:
require File.dirname(__FILE__) + '/lib/networks/code1.rb'
Where code1.rb includes:
class App < Sinatra::Application
if params['login'] # == 'login'
pass = 'uampass'
elsif
...
But that gives me the following error:
undefined local variable or method `params' for main:Object
How can I refactor this without causing an error
As far as i know you can't use two (or more) Sinatra applications in, well one application. Since both files define a Sinatra::Application descendant this isn't possible.
Also if you want to use values from the params-hash you should define helper methods Helper Documentation, which you call when processing the route, or you just create Class which has class or instance methods which take params-values as parameters. Actually calling params from another file/class doesn't seem like good practice.
To put this in context: Sinatra applications are organised as handlers. The Sinatra::Application descendant is something like the main handler which uses support methods(helpers and instance methods of the Sinatra::Application descendant) or support Classes, which are usually defined in other files, but do not descend from Sinatra::Application.
To make this a little bit more clearly:
Your main Sinatra file:
require_relative 'another_file.rb'
class App < Sinatra::Application
# ...
#a_handler = MyHandler.new
get '/' do
if params['something'] == 'wanted_value'
#a_handler.handle_it(params)
end
end
Another file ('another_file.rb'):
class MyHandler
def initialize
#an_instance_variable = 'foobar'
end
def handle_it(params_hash)
if params_hash['login'] # == 'login'
pass = 'uampass'
elsif
# ...
end
# ...
# do some stuff
# ....
return pass
end
end
Actual code would of course depend on the real problem you're trying to solve, so if you would elaborate i could be more precise...
The error message contains everything you need to know, and it's nothing to do with Sinatra.
You are requiring code1.rb, which contains this (slightly edited so it will run):
require 'sinatra'
class App < Sinatra::Application
if params['login'] # == 'login'
pass = 'uampass'
end
end
Ruby evaluates code as it encounters it. In this case, you've required 'code1.rb', so it evaluates the code in that file. It encounters 'params' and asks "is there a local variable or method with that name?". There isn't, so it fails as you've seen. Open an irb session and check it out.
Class definitions in ruby are just an expression with a scope.
In relation to Sinatra: params is available in the block that a route declaration takes.
I'd recommend reading Sinatra: Up and Running, which explains some of the 'magic' that is going on (a good companion to the Sinatra Book).
I've seen this asked a few times in other threads, but none of the answers seem to apply.
Environment:
Rails 3
amazon/ecs gem from jugend. The lone file is here:
http://github.com/jugend/amazon-ecs/blob/master/lib/amazon/ecs.rb
my gemfile has:
gem 'amazon-ecs', :git => 'git://github.com/jugend/amazon-ecs.git'
Everything works in irb. I can run:
bundle console
require 'amazon/ecs' and then go to town
when I try to use it from the controller though, like so:
require 'amazon/ecs'
require 'amazon/ecs'
class SearchController < ApplicationController
def index
end
def results
Amazon::Ecs.configure do |options|
options[:aWS_access_key_id] = '[key]'
options[:aWS_secret_key] = '[secret]'
end
res = Amazon::Ecs.item_search(params[:search], {:response_group => 'Medium', :search_index => 'All'})
end
end
I get: uninitialized constant SearchController::Amazon at line 8, where I first try to use Amazon.
the ecs.rb has a module Amazon containing a class Ecs. I'm not sure why this is working in erb, and not in rails.
I'm still kinda new to Rails, so please answer using small words. :-/
Was given the answer. I moved my initialization code to an initializer in config/initializers file, removed the require entirely, and things worked. I don't know why though, so if someone could answer that, that'd be great.
All of the gems require their files by default, so usually you don't need to explicitly require any files.
Speaking about your problem, it could somehow be, that your controller is run before Amazon module is processed.