I've placed the file rack_app.rb with simple Rack application in the lib directory:
class RackApp
def call env
[200, {}, 'Hello']
end
end
Then I've added this route:
match 'rack' => RackApp
And when I try to launch the rails server I get the following error:
config/routes.rb:65: uninitialized constant RackApp (NameError)
Rails 3 has no more autoloading by default. So you need require your file
require 'lib/rack_app.rb'
Or come back the autoloading in application.rb
config.autoload_paths += %W( #{config.root}/lib )
Include require 'email_format_validator' in the model.
Related
I'm trying to update my app from Rails 5.2 to 6.1, and use Zeitwerk autoload, and I am having some issues for autoloading /lib classes.
I included this in config/application.rb:
config.load_defaults 5.2
config.autoloader = :zeitwerk
config.enable_dependency_loading = true
config.autoload_paths += Dir[Rails.root.join('lib/**/*')]
config.eager_load_paths += Dir[Rails.root.join('lib/**/*')]
And, when I run zeitwerk:check, it alerts me that:
Hold on, I am eager loading the application.
expected file lib/facades/coconut/v2/foo.rb to define constant Foo
It is declared as:
# /lib/facades/coconut/v2/foo.rb
module Coconut
module V2
class Foo
# ...
end
end
end
When I try to debug it (putting a binding.pry in some test file), Zeitwerk says it do not defined, until I call it without modules (namespaces):
[1] pry(#<#filename>)> Coconut::V2::Foo
NameError: uninitialized constant Coconut::V2::Foo
from (pry):1:in `setup`
[2] pry(#<#filename>)> Foo
Zeitwerk::NameError: expected file /my-app/lib/api/coconut/v2/foo.rb to define constant Foo, but didn't
from /usr/local/bundle/gems/zeitwerk-2.5.4/lib/zeitwerk/loader/callbacks.rb:25:in `on_file_autoloaded'
[3] pry(#<#filename>)> Coconut::V2::Foo
=> Coconut::V2::Foo
It sounds really strange, because there are another classes in /lib that follows the same structure, but it works well, example
# /lib/api/services/youtube/client.rb
module Services
module Youtube
class Client
# ...
end
end
end
Inspecting it with binding.pry in some test:
pry(#<#filename>)> Services::Youtube::Client
=> Services::Youtube::Client
Has anyone had this problem or know what could be happening?
System:
ruby 2.7.6p219
Rails 6.1.6
Zeitwerk (2.5.4)
An autoload path is a root directory, not its contents.
You need to remove the wildcards as documented here.
I have some code i've inherited and am in the process of upgrading it to Rails 3.1. I'm suuuuper close to done but I got a bug.
In Rails Console I run User.first and I get this error
undefined local variable or method `acts_as_userstamp' for #<Class:0x000000046bef50>
Now acts_as_userstamp is a method located on line two inside my User model
class User < ActiveRecord::Base
#TODO /lib is not loading??? or is it??? why this method not work in browser?
acts_as_userstamp
And is defined in a file called app/lib/model_modifications.rb.
Now I recently discovered that my app/lib folder was not being autoloaded in my application.rb file and I think that's been fixed...or has it? Is this file correct? Or no?
require File.expand_path('../boot', __FILE__)
require 'rails/all'
# evil outdated soap middleware, TODO: kill it with fire
# Does this have to be loaded BEFORE the first line???
$LOAD_PATH.unshift(File.join(File.dirname(__FILE__), '..', "vendor", "soap4r"))
$LOAD_PATH.unshift(File.join(File.dirname(__FILE__), '..', "vendor", "plugins", "soap4r-middleware", "lib"))
# evil outdated soap middleware, TODO: kill it with fire
require 'soap4r-middleware'
require File.join(File.dirname(__FILE__), '..', 'app', 'lib', 'soap.rb')
if defined?(Bundler)
# If you precompile assets before deploying to production, use this line
Bundler.require *Rails.groups(:assets => %w(development test))
# If you want your assets lazily compiled in production, use this line
# Bundler.require(:default, :assets, Rails.env)
end
module MyappDev
class Application < Rails::Application
# startup the lib directory goodies <-- IS THIS CORRECT???
# config.autoload_paths << "#{Rails.root}/lib"
# config.autoload_paths += %W( lib/ )
config.autoload_paths += %W(#{config.root}/lib)
config.autoload_paths += Dir["#{config.root}/lib/**/"]
# Configure the default encoding used in templates for Ruby 1.9.
config.encoding = "utf-8"
# Configure sensitive parameters which will be filtered from the log file.
config.filter_parameters += [:password]
config.middleware.use MyAPIMiddleware
end
end
I'm trying to debug this file as I post this now. Here is a peak at it's internal structure...(i've just included the overall structure for the sake of brevity)
app/lib/model_modificatons.rb
class Bignum
...
end
class Fixnum
...
end
class ProcessorDaemon
...
end
module ActiveRecord
module UserMonitor
...
end
module MyLogger
...
end
end
class Object
...
end
class Struct
...
end
class String
...
end
class Fixnum
...
end
class OpenStruct
...
end
class ActiveRecord::Base
def self.visible_columns
...
end
...
def self.acts_as_userstamp
logger.info "HI fonso - acts_as_userstamp is called"
include ActiveRecord::UserMonitor
end
...
protected
def self.range_math(*ranges)
...
end
end
class Array
...
end
class DB
...
end
If you can spot a problem with the overall structure or anywhere else please let me know.
So why is this method not found? I'm trying to debug it as I'm posting this and I'm getting nothing.
I suspect the file app/lib/model_modifications.rb is not being loading. That nothing in the /lib directory is being loaded..but how do I confirm this?
Thank you for reading this far, I hope I've not rambled on too much.
autoload_path configuration does not load all the given files on the boot but defines folders where rails will be searching for defined constants.
When your application is loaded, most of the constants in your application are not there. Rails have a "clever" way of delaying loading the files by using a constant_missing method on Module. Basically, when Ruby encounters a constant in the code and fails to resolve it, it executes said method. THe sntandard implementation of this method is to raise UndefinedConstant exception, but rails overrides it to search all of its autoload_paths for a file with a name matching the missing constant, require it and then check again if the missing constant is now present.
So, in your code everything works as expected and you need to load this extension file manually. If you want to have some code that executes on the application boot, put your file within config/initializers folder.
Aside: Try avoiding monkey patching whenever possible. It might be looking clever, but adding more methods to already overpopulated classes will not make them easier to use.
I've created a file as lib/services/my_service.rb.
# /lib/services/my_service.rb
class MyService
...
end
I want to use it in app/controllers/my_controller
class MyController < ApplicationController
def method
service = MyService.new()
end
I'm getting an error that MyService is an uninitialized constant. I've tried to import it with
require '/lib/services/my_service.rb'
But I'm getting
cannot load such file -- /lib/services/my_service.rb
Edit: I have tried autoloading from application.rb using
config.autoload_paths << Rails.root.join('lib')
But no dice. Still getting uninitialized constant MyController::MyService
Ruby on Rails requires following certain naming conventions to support autoloading.
Rails can autoload a file located at lib/services/my_service.rb if the model/class structure was Services::MyService.
Change your lib/services/my_service.rb to:
module Services
class MyService
# ...
end
end
And use that class like this in your controller:
service = Services::MyService.new
Please note that depending on your Ruby on Rails version, you might need to add the lib folder to the list of folders which are queried when looking for a file to autoload:
# add this line to your config/application.rb:
config.autoload_paths << "#{Rails.root}/lib"
Read more about autoloading in the Rails Guides.
You probably need to enable the autoload from the files in the lib/ folder:
# config/application.rb
config.autoload_paths << "#{Rails.root}/lib"
If you prefer to do it "manually", then you can only require such file in the same file:
# config/application.rb
require './lib/my_service'
After this a restart is necessary.
there is a setting in config/application.rb in which you can specify directories that contain files you want autoloaded.
From application.rb:
# Custom directories with classes and modules you want to be autoloadable.
# config.autoload_paths += %W(#{config.root}/extras)
or
config.autoload_paths += Dir["#{config.root}/lib/**/"]
rails 3
Dir["lib/**/*.rb"].each do |path|
require_dependency path
end
Add this in your application.rb
config.eager_load_paths << Rails.root.join('lib/services')
I am trying to learn Middlewares and been practising how to mount it in the Rails application. I have followed the railscast
So far I have implemented these steps:
1) Created a new Rails 4.2 application called: Blog
2) Added a file in the lib folder named as response_timer.rb.
class ResponseTimer
def initialize(app)
#app = app
end
def call(env)
[200, {"Content-Type" => "text/html"}, "Hello World"]
end
end
3) Added config.middleware.use "ResponseTimer" in application.rb.
config.middleware.use "ResponseTimer"
But as i'm hitting the command rake middleware in the terminal, it is reporting this error:
rake aborted!
NameError: uninitialized constant ResponseTimer
I tried also to add the config.middleware.use "ResponseTimer" in the development.rb but again facing the same error.
What am i missing here?
Please help.
Referenced article: http://guides.rubyonrails.org/rails_on_rack.html
Middleware has to have an accompanying module / class, and needs to be loaded in the app before it can be referenced. The way to do this in Rails is with autoloading (lib files aren't autoloaded by default):
#config/application.rb
config.autoload_paths += Dir["#{config.root}/lib/**/"]
config.middleware.use "ResponseTimer"
The above should work for you.
I followed this answer: https://stackoverflow.com/a/24122424
I tried it before but maybe missed something before.
In appliation.rb
require 'rails/all'
require_relative '../lib/response_timer'
module Blog
class Application < Rails::Application
...
config.middleware.use ResponseTimer
end
end
I'm currently migrating an application in rails v2 to v3
In my lib/ i've some modules in subdirectories, for example,
i've the lib/search/host_search.rb
with a
module HostSearch
def do_search(args)
#...
end
end
then I need to use it in a controller named Discovery::HostController < ApplicationController :
def search_results
output = HostSearch.do_search(:search_string => #search_string,
:page => params[:page],
:user => #current_user)
#...
end
But have I get:
uninitialized constant Discovery::HostController::HostSearch
..I tried to put this lines in application.rb but it doesn't work..
config.autoload_paths += %W(#{config.root}/lib)
config.autoload_paths += Dir["#{config.root}/lib/**/"]
I found that moving the module to the lib folder or explicitly including the folder to load worked, in your case
config.autoload_paths += %W(#{config.root}/lib/search)
I think there's something syntaxical that we are missing. Another thing is that if you don't want to mess with the application.rb file, require the file, which if I remember, takes the file path from the lib folder eg: search/host_search <- check that.
I think if you put the HostSearch module under a search subdir, (ie in lib/search/host_search.rb), then you need to namespace it:
module Search
module HostSearch
end
end
If you don't want to namespace it, you can should move the file into the lib root: lib/host_search.rb.
See also: https://stackoverflow.com/a/19650564/514483