Emulation of each_slice without block in ruby < 1.8.7 - ruby-on-rails

Im trying to test my rails applications javascript using jruby 1.3.1,celerity and culerity.
The application itself runs under ruby 1.8.7 + phusion passenger (and runs fine, sans test :))
Everything installation-wise works fine but my app uses some_enumerable.each_slice(10) to split a larger array into smaller subarray with 10 elelents each.
Celerity need jruby and jruby is only ruby 1.8.6 compatible and therefor doesnt support a blockless each_slice.
So I'm thinking about defining an initalizer which adds this functionality if RUBY_PLATFORM == "java " (or RUBY_VERSION < 1.8.7)
This far I got (defunct code of cause):
if true #ruby 1.8.6
module Enumerable
alias_method :original_each_slice, :each_slice
def each_slice(count, &block)
# call original method in 1.8.6
if block_given?
original_each_slice(count, block)
else
self.enum_for(:original_each_slice, count).to_a
end
end
end
end
This code obviously is not working and I would really appreciate someone pointing me to a solution.
Thanks!
Update:
Solution thanks to sepp2k for pointing me to my errors:
if RUBY_VERSION < "1.8.7"
require 'enumerator'
module Enumerable
alias_method :original_each_slice, :each_slice
def each_slice(count, &block)
if block_given?
# call original method when used with block
original_each_slice(count, &block)
else
# no block -> emulate
self.enum_for(:original_each_slice, count)
end
end
end
end

original_each_slice(count, block) should be original_each_slice(count, &block).
Also if you leave out the to_a, you'll be closer to the behaviour of 1.8.7+, which returns an enumerator, not an array.
(Don't forget to require 'enumerator' btw)

checkout the 'backports' gem :)

Related

rails - files in autoload_paths folder aren't loaded

I have a app/extensions folder where my custom exceptions reside and where I extend some of the Ruby/Rails classes. Currently there are two files: exceptions.rb and float.rb.
The folder is specified in the ActiveSupport::Dependencies.autoload_paths:
/Users/mityakoval/rails/efo/app/extensions/**
/Users/mityakoval/rails/efo/app/assets
/Users/mityakoval/rails/efo/app/channels
/Users/mityakoval/rails/efo/app/controllers
/Users/mityakoval/rails/efo/app/controllers/concerns
/Users/mityakoval/rails/efo/app/extensions
/Users/mityakoval/rails/efo/app/helpers
/Users/mityakoval/rails/efo/app/jobs
/Users/mityakoval/rails/efo/app/mailers
/Users/mityakoval/rails/efo/app/models
/Users/mityakoval/rails/efo/app/models/concerns
/Users/mityakoval/rails/efo/app/template.xlsx
/Users/mityakoval/.rvm/gems/ruby-2.4.1#web_app/gems/font-awesome-rails-4.7.0.2/app/assets
/Users/mityakoval/.rvm/gems/ruby-2.4.1#web_app/gems/font-awesome-rails-4.7.0.2/app/helpers
/Users/mityakoval/rails/efo/test/mailers/previews
The reason for it to be listed there twice is that it should be automatically loaded since it was placed under app directory and I have also manually added it to the autoload_paths in application.rb:
config.autoload_paths << File.join(Rails.root, 'app', 'extensions/**')
The strange thing is that my exceptions.rb is successfully loaded at all times, but the float.rb isn't unless eager loading is enabled.
Answers to this question say that it might be related to Spring (which I tend to believe), so I've added the folder to spring.rb:
%w(
.ruby-version
.rbenv-vars
tmp/restart.txt
tmp/caching-dev.txt
config/application.yml
app/extensions
).each { |path| Spring.watch(path) }
I've restarted Spring and the Rails server multiple times and nothing worked. Does anyone have any suggestions?
Ruby version: 2.4.1
Rails version: 5.1.5
EDIT
/Users/mityakoval/rails/efo/app/extensions/float.rb:
class Float
def comma_sep
self.to_s.gsub('.', ',')
end
end
rails console:
irb> num = 29.1
irb> num.comma_sep
NoMethodError: undefined method `comma_sep' for 29.1:Float
from (irb):2
A better way to monkeypatch a core class is by creating a module and including it in the class to be patched in an initializer:
# /lib/core_extensions/comma_seperated.rb
module CoreExtensions
module CommaSeperated
def comma_sep
self.to_s.gsub('.', ',')
end
end
end
# /app/initializers/core_extensions.rb
require Rails.root.join('lib', 'core_extensions', 'comma_seperated')
# or to require all files in dir:
Dir.glob(Rails.root.join('lib', 'core_extensions', '*.rb')).each do |f|
require f
end
Float.include CoreExtensions::CommaSeperated
Note that here we are not using the Rails autoloader at all and explicitly requiring the patch. Also note that we are placing the files in /lib not /app. Any files that are not application specific should be placed /lib.
Placing the monkey-patch in a module lets you test the code by including it in an arbitrary class.
class DummyFloat
include CoreExtensions::CommaSeperated
def initialize(value)
#value = value
end
def to_s
#value.to_s
end
end
RSpec.describe CoreExtensions::CommaSeperated do
subject { DummyFloat.new(1.01) }
it "produces a comma seperated string" do
expect(subject.comma_sep).to eq "1,01"
end
end
This also provides a much better stacktrace and makes it much easier to turn the monkey patch off and on.
But in this case I would argue that you don't need it in the first place - Rails has plenty of helpers to humanize and localize numbers in ActionView::Helpers::NumberHelper. NumberHelper also correctly provides helper methods instead of monkeypatching a core Ruby class which is generally best avoided.
See:
3 Ways to Monkey-Patch Without Making a Mess

Ruby: How to make a public static method?

In Java I might do:
public static void doSomething();
And then I can access the method statically without making an instance:
className.doSomething();
How can I do that in Ruby? this is my class and from my understanding self. makes the method static:
class Ask
def self.make_permalink(phrase)
phrase.strip.downcase.gsub! /\ +/, '-'
end
end
But when i try to call:
Ask.make_permalink("make a slug out of this line")
I get:
undefined method `make_permalink' for Ask:Class
Why is that if i haven't declared the method to be private?
Your given example is working very well
class Ask
def self.make_permalink(phrase)
phrase.strip.downcase.gsub! /\ +/, '-'
end
end
Ask.make_permalink("make a slug out of this line")
I tried in 1.8.7 and also in 1.9.3
Do you have a typo in you original script?
All the best
There is one more syntax which is has the benefit that you can add more static methods
class TestClass
# all methods in this block are static
class << self
def first_method
# body omitted
end
def second_method_etc
# body omitted
end
end
# more typing because of the self. but much clear that the method is static
def self.first_method
# body omitted
end
def self.second_method_etc
# body omitted
end
end
Here's my copy/paste of your code into IRB. Seems to work fine.
$ irb
1.8.7 :001 > class Ask
1.8.7 :002?>
1.8.7 :003 > def self.make_permalink(phrase)
1.8.7 :004?> phrase.strip.downcase.gsub! /\ +/, '-'
1.8.7 :005?> end
1.8.7 :006?>
1.8.7 :007 > end
=> nil
1.8.7 :008 > Ask.make_permalink("make a slug out of this line")
=> "make-a-slug-out-of-this-line"
Seems to work. Test it out in your irb as well, and see what results you're getting. I'm using 1.8.7 in this example, but I also tried it in a Ruby 1.9.3 session and it worked identically.
Are you using MRI as your Ruby implementation (not that I think that should make a difference in this case)?
In irb make a call to Ask.public_methods and make sure your method name is in the list. For example:
1.8.7 :008 > Ask.public_methods
=> [:make_permalink, :allocate, :new, :superclass, :freeze, :===,
...etc, etc.]
Since you also marked this as a ruby-on-rails question, if you want to troubleshoot the actual model in your app, you can of course use the rails console: (bundle exec rails c) and verify the publicness of the method in question.
I am using ruby 1.9.3 and the program is running smoothly in my irb as well.
1.9.3-p286 :001 > class Ask
1.9.3-p286 :002?> def self.make_permalink(phrase)
1.9.3-p286 :003?> phrase.strip.downcase.gsub! /\ +/, '-'
1.9.3-p286 :004?> end
1.9.3-p286 :005?> end
=> nil
1.9.3-p286 :006 > Ask.make_permalink("make a slug out of this line")
=> "make-a-slug-out-of-this-line"
It's also working in my test script. Nothing wrong with your given code.It's fine.

Stop / terminate rails generator

I'm writing an upgrade generator for my gem and I want it to check if my gem is installed. That's not a problem, but if the gem is not installed I want to terminate the rest of the methods.
Here is my code so far:
module Baco
module Generators
class UpgradeGenerator < Rails::Generators::Base
def check_installation
unless File.exists?( File.join( destination_root, "config", "initializers", "baco.rb" ) )
p "Baco not yet installed. Please run 'rails generate baco:install' to install"
# Here the generator needs to stop everything!
end
end
def next_method
# We don't want this if the gem is not installed!
end
end
end
end
Anybody can point me to the right method to use?
I believe you can raise an Error, and that should stop the generator.

learning RoR, can someone explain this boot.rb from H**ll?

I am looking at this boot.rb file:
http://github.com/bestbuyremix/BBYIDX/blob/master/config/boot.rb
And after trying to understand it, it is as if I have learned nothing so far.
Can someone detail what is going on here?
I have no idea how someone could even come up with this?
# Don't change this file!
# Configure your app in config/environment.rb and config/environments/*.rb
RAILS_ROOT = "#{File.dirname(__FILE__)}/.." unless defined?(RAILS_ROOT)
module Rails
class << self
def boot!
unless booted?
preinitialize
pick_boot.run
end
end
def booted?
defined? Rails::Initializer
end
def pick_boot
(vendor_rails? ? VendorBoot : GemBoot).new
end
def vendor_rails?
File.exist?("#{RAILS_ROOT}/vendor/rails")
end
def preinitialize
load(preinitializer_path) if File.exist?(preinitializer_path)
end
def preinitializer_path
"#{RAILS_ROOT}/config/preinitializer.rb"
end
end
class Boot
def run
load_initializer
Rails::Initializer.run(:set_load_path)
end
end
class VendorBoot < Boot
def load_initializer
require "#{RAILS_ROOT}/vendor/rails/railties/lib/initializer"
Rails::Initializer.run(:install_gem_spec_stubs)
end
end
class GemBoot < Boot
def load_initializer
self.class.load_rubygems
load_rails_gem
require 'initializer'
end
def load_rails_gem
if version = self.class.gem_version
gem 'rails', version
else
gem 'rails'
end
rescue Gem::LoadError => load_error
$stderr.puts %(Missing the Rails #{version} gem. Please `gem install -v=#{version} rails`, update your RAILS_GEM_VERSION setting in config/environment.rb for the Rails version you do have installed, or comment out RAILS_GEM_VERSION to use the latest version installed.)
exit 1
end
class << self
def rubygems_version
Gem::RubyGemsVersion if defined? Gem::RubyGemsVersion
end
def gem_version
if defined? RAILS_GEM_VERSION
RAILS_GEM_VERSION
elsif ENV.include?('RAILS_GEM_VERSION')
ENV['RAILS_GEM_VERSION']
else
parse_gem_version(read_environment_rb)
end
end
def load_rubygems
require 'rubygems'
min_version = '1.1.1'
unless rubygems_version >= min_version
$stderr.puts %Q(Rails requires RubyGems >= #{min_version} (you have #{rubygems_version}). Please `gem update --system` and try again.)
exit 1
end
rescue LoadError
$stderr.puts %Q(Rails requires RubyGems >= #{min_version}. Please install RubyGems and try again: http://rubygems.rubyforge.org)
exit 1
end
def parse_gem_version(text)
$1 if text =~ /^[^#]*RAILS_GEM_VERSION\s*=\s*["']([!~<>=]*\s*[\d.]+)["']/
end
private
def read_environment_rb
File.read("#{RAILS_ROOT}/config/environment.rb")
end
end
end
end
# All that for this:
Rails.boot!
If you are learning Rails, this is not the place to do it. Perhaps you have the thought that in order to use it, you need to understand how the code flows from the beginning? Don't do that. :)
If you're learning rails, use any of the many guides and tutorials to build a basic site.
As for this bit of code, some concepts that it employs involve ruby's iconic class << self Here is a critical read on meta classes: http://yehudakatz.com/2009/11/15/metaprogramming-in-ruby-its-all-about-the-self/
The Rails.boot! at the bottom leads you to the conclusion "the method boot! is called on the object Rails ... going back up to the top, you see
module Rails
class << self
def boot!
unless booted?
preinitialize
pick_boot.run
end
end
...
Here you can see the magic behind class << self ... it created the boot! method on the module itself. from there you can trace the method call throughout the file, as it checks for the existence of a preinitializer file...
pick_boot returns an object, either VendorBoot or GemBoot depending on the result of vendor_rails? and then call the run method on it.
From there you have some standard class inheritance of the Boot classes, as it sets up the rest of the libraries. Hopefully that gets you started. :)
This is actually very good OO style... small methods and classes that all do a simple task. There's also OO inheritance and several common ruby idioms. All in all, a very good bit of ruby code. :)
Update
Here's a rough estimate of how it would look if coded in a more procedural style:
RAILS_ROOT = "#{File.dirname(__FILE__)}/.." unless defined?(RAILS_ROOT)
unless defined? Rails::Initializer
preinitializer_path = "#{RAILS_ROOT}/config/preinitializer.rb"
load() if File.exist?(preinitializer_path)
if File.exist?("#{RAILS_ROOT}/vendor/rails")
require "#{RAILS_ROOT}/vendor/rails/railties/lib/initializer"
Rails::Initializer.run(:install_gem_spec_stubs)
Rails::Initializer.run(:set_load_path)
else
begin
require 'rubygems'
min_version = '1.1.1'
rubygems_version = Gem::RubyGemsVersion if defined? Gem::RubyGemsVersion
unless rubygems_version >= min_version
$stderr.puts %Q(Rails requires RubyGems >= #{min_version} (you have #{rubygems_version}). Please `gem update --system` and try again.)
exit 1
end
rescue LoadError
$stderr.puts %Q(Rails requires RubyGems >= #{min_version}. Please install RubyGems and try again: http://rubygems.rubyforge.org)
exit 1
end
begin
if defined? RAILS_GEM_VERSION
version = RAILS_GEM_VERSION
elsif ENV.include?('RAILS_GEM_VERSION')
version = ENV['RAILS_GEM_VERSION']
else
version = $1 if (File.read("#{RAILS_ROOT}/config/environment.rb")) =~ /^[^#]*RAILS_GEM_VERSION\s*=\s*["']([!~=]*\s*[\d.]+)["']/
end
if version
gem 'rails', version
else
gem 'rails'
end
rescue Gem::LoadError => load_error
$stderr.puts %(Missing the Rails #{version} gem. Please `gem install -v=#{version} rails`, update your RAILS_GEM_VERSION setting in config/environment.rb for the Rails version you do have installed, or comment out RAILS_GEM_VERSION to use the latest version installed.)
exit 1
end
require 'initializer'
end
end
What this is really doing is a bunch of fancy footwork to determine where the rails source code is.
You have the ability to 'freeze' your current rails gem source code into the vendor directory. This is useful when you might have more than one version of rails installed and want to make sure that your application is developed and run with that version only.
This code is checking to see if a version of rails has been frozen into the vendor directory, and if so, use that. If a frozen version isn't available it tries to use the local gems, but first makes sure they meet a minimum version requirement.
For more information on 'freezing' your gems, look at the descriptions of the rake tasks availble to your project with "rake -T".

Why is this line breaking Rails with Passenger on DreamHost?

Ok, so I have a Rails app set up on DreamHost and I had it working a while ago and now it's broken. I don't know a lot about deployment environments or anything like that so please forgive my ignorance. Anyway, it looks like the app is crashing at this line in config/environment.rb:
require File.join(File.dirname(__FILE__), 'boot')
config/boot.rb is pretty much normal, but I'll include it here anyway.
# Don't change this file!
# Configure your app in config/environment.rb and config/environments/*.rb
RAILS_ROOT = "#{File.dirname(__FILE__)}/.." unless defined?(RAILS_ROOT)
module Rails
class << self
def boot!
unless booted?
preinitialize
pick_boot.run
end
end
def booted?
defined? Rails::Initializer
end
def pick_boot
(vendor_rails? ? VendorBoot : GemBoot).new
end
def vendor_rails?
File.exist?("#{RAILS_ROOT}/vendor/rails")
end
def preinitialize
load(preinitializer_path) if File.exist?(preinitializer_path)
end
def preinitializer_path
"#{RAILS_ROOT}/config/preinitializer.rb"
end
end
class Boot
def run
load_initializer
Rails::Initializer.run(:set_load_path)
end
end
class VendorBoot < Boot
def load_initializer
require "#{RAILS_ROOT}/vendor/rails/railties/lib/initializer"
Rails::Initializer.run(:install_gem_spec_stubs)
end
end
class GemBoot < Boot
def load_initializer
self.class.load_rubygems
load_rails_gem
require 'initializer'
end
def load_rails_gem
if version = self.class.gem_version
gem 'rails', version
else
gem 'rails'
end
rescue Gem::LoadError => load_error
$stderr.puts %(Missing the Rails #{version} gem. Please `gem install -v=#{version} rails`, update your RAILS_GEM_VERSION setting in config/environment.rb for the Rails version you do have installed, or comment out RAILS_GEM_VERSION to use the latest version installed.)
exit 1
end
class << self
def rubygems_version
Gem::RubyGemsVersion if defined? Gem::RubyGemsVersion
end
def gem_version
if defined? RAILS_GEM_VERSION
RAILS_GEM_VERSION
elsif ENV.include?('RAILS_GEM_VERSION')
ENV['RAILS_GEM_VERSION']
else
parse_gem_version(read_environment_rb)
end
end
def load_rubygems
require 'rubygems'
min_version = '1.1.1'
unless rubygems_version >= min_version
$stderr.puts %Q(Rails requires RubyGems >= #{min_version} (you have #{rubygems_version}). Please `gem update --system` and try again.)
exit 1
end
rescue LoadError
$stderr.puts %Q(Rails requires RubyGems >= #{min_version}. Please install RubyGems and try again: http://rubygems.rubyforge.org)
exit 1
end
def parse_gem_version(text)
$1 if text =~ /^[^#]*RAILS_GEM_VERSION\s*=\s*["']([!~<>=]*\s*[\d.]+)["']/
end
private
def read_environment_rb
File.read("#{RAILS_ROOT}/config/environment.rb")
end
end
end
end
# All that for this:
Rails.boot!
Does anyone have any ideas? I am not getting any errors in the log or on the page.
-fREW
I had the same problem on DreamHost. Freezing rails and unpacking all gems got me past it.
rake rails:freeze:gems
rake gems:unpack:dependencies
My guess would be that you're breaking because of a newer version of the Rails gems on Dreamhost. At least, that's been my issue when things have blown up in something like boot.rb.
Try freezing the gems from your development environment into your vendor/rails directory.
Ya - the problem is not really in boot.rb - it's just that boot.rb is where rails is actually loaded.
So you'll get an error like this if you've specified a version of Rails that just doesn't exist on your dreamhost slice. This can happen if you either upgrade your project, start a new project (and forget that you upgraded rails in the meanwhile) or if you're still using an old version of rails and it's now been removed from the dreamhost server that you're on.
To figure out which is is, look in config/environment.rb for the line that'll read something like:
RAILS_GEM_VERSION = '2.3.4' unless defined? RAILS_GEM_VERSION
Then ssh to your dreamhost server and type gem list and see if your version is in the list.
If not, you an try several options. Lets say the version you're using is 2.3.4
To begin with, try: gem install rails -v=2.3.4 then restart. That may be all that is required.
If that doesn't work, then try freezing and unpacking the gems (as per the other answer here).
There is also another possibility - that you're actually missing a gem that rails depends on but which is failing silently - eg a dependency on a certain version of rack caught me out once. But you may also have other gem dependencies
If you run rake gems you will be able to list all the gems that your project knows about that it needs - make sure they're installed to begin with.
Then, as a sort of rough smoke-test, try running script/console - if you're missing an important rails gem, script/console won't load and should fail, giving you a notice about the gem you need.
Update:
If you're trying to run v 2.3.5, you may also be suffering from this problem:
Bypassing rack version error using Rails 2.3.5
In which case you'll need to follow the instructions there.

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