How do I include module into ActionView from the lib directory? - ruby-on-rails

I am attempting to add a new module of custom helpers to the ActionView::Base library. I was able to get the module to load from the config/initializers directory but when I load it into the lib, the module is no longer found. I have:
# lib/my_templates/helper.rb
module MyTemplates
module Helper
def print_me
return 'me'
end
end
end
ActionView::Base.send(:include, AtlasTemplates::Helper)
In the application.rb
config.autoload_paths += Dir["#{config.root}/lib", "#{config.root}/lib/**/"]
If I put helper.rb into the config/initializers then <%= print_me -%> works just fine. If I move it to it's lib location then I get undefined local variable or methodprint_me'`
I am definitely missing something here.

Related

undefined local variable or method for method located in lib directory file

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# evil outdated soap middleware, TODO: kill it with fire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# evil outdated soap middleware, TODO: kill it with fire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.

How to monkey patch Array in Rails lib subfolder?

I have a standard Rails 5.2 application and I would like to add a method to an Array class.
So I have created a file in lib/core_extensions/array/use_slugs.rb with this code:
module CoreExtensions
module Array
def use_slugs
binding.pry
end
end
end
Array.include CoreExtensions::Array
and in my config/application.rb file I have added:
class Application < Rails::Application
...
config.eager_load_paths << Rails.root.join('lib')
config.eager_load_paths << Rails.root.join('lib', 'core_extensions', '**/')
...
end
But still when I call [].use_slugs I get undefined method 'use_slugs' for []:Array
Why?
Thanks
Ok, for someone else. I have decided no to load the entire lib folder in the application.rb file at all, because generally you don't want to load all rake tasks etc. (so I have deleted the config.eager_load_paths << Rails.root.join('lib') and config.eager_load_paths << Rails.root.join('lib', 'core_extensions', '**/') lines from application.rb)
I have kept the folder structure in the lib folder same, but I'm loading only particular files and lib subfolders in the config/initializers/lib_init.rb file I have created, like this:
require Rails.root.join('lib', 'sp_form_builder.rb')
Dir[ Rails.root.join('lib', 'core_extensions', '**') ].each { |f| require f }

Adding lib to config autoload paths does not autoload my module in Rails 3

Adding lib to config autoload paths does not autoload my module in Rails 3.
I add in my config/application.rb file.
config.autoload_paths += %W(#{config.root}/lib)
config.autoload_paths += Dir["#{config.root}/lib/**/"]
In my controller I added
require 'lib_util' (or)
include LibUtil #both doesn't work
In my lib/lib_util.rb file, I have the following module
module LibUtil
module ClassMethods
def p_key(a,b)
//mycode
end
end
def self.included(receiver)
receiver.extend ClassMethods
end
end
I get the error undefined method `p_key'. The important thing to be noted is I ve called the same module in my model it works fine. But in my controller it does not identify the module.
Can anybody guide me??
Did you try including both the modules ?
include LibUtil::ClassMethods

Namespaced modules and Rails 3.1.3 autoload_path

I'm having some trouble to namespace a module that I include in a model.
in /app/models/car.rb
class Car
include Search::Car
end
in /lib/search/car.rb
module Search
module Car
include ActiveSupport::Concern
# methods in here
end
end
in /config/application.rb
config.autoload_paths += Dir["#{config.root}/lib/**/"]
config.autoload_paths += Dir["#{config.root}/lib/search/*"]
The weird thing is that I don't get any errors directly when I fire up the server.
But if I refresh the browser after a while I get this error:
Expected #{Rails.root}/lib/search/car.rb to define Car
The nature of the problem indicates that it has something to do with:
/config/environments/development.rb
config.cache_classes = false
I also tried put a file search.rb directly in /lib where I define Search:
module Search
# Put shared methods here
end
What am I doing wrong?
UPDATE:
Ok, turns out that if I rename Search::Car to Search::CarSearch it works.
Is it not possible to have Modules/Classes of the same name in a different scope?
The error is coming from your autoload_paths. config.autoload_paths += Dir["#{config.root}/lib/**/"] will add all directories and their subdirectories under lib directory. meaning that you are telling rails to autoload lib/search/ directory, therefore car.rb under that directory is expected to define Car and not Search::Car. In order for rails to expect lib/search/car.rb to define Search::Car, you need to autoload lib/ directory and not lib/search. if you change you autoload to config.autoload_paths += Dir["#{config.root}/lib/"] and put search.rb in lib/ with following code:
module Search
require 'search/car'
end
then rails will understand and expect lib/search/car.rb do define Search::Car and referencing Car module/class in other places of your code will not reference to this car.rb.
You should remove this line (you should only have autoload for lib directory):
config.autoload_paths += Dir["#{config.root}/lib/search/*"]

cant load lib directory modules - uninitialized constant - rails 2 to rails 3 upgrade

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

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