What is the best/easiest way to configure logging for code kept in the lib directory?
There's two ways to go about it:
Assuming your library is self-contained and has a module, you can add a logger attribute to your module and use that everywhere in your library code.
module MyLibrary
mattr_accessor :logger
end
You then either use an initializer in config/initializers/, or an config.after_initialize block in config/environment.rb to initialize your logger, like so:
require 'mylibrary'
MyLibrary.logger = Rails.logger
This would still allow you to use your self-contained library from scripts outside of Rails. Which is nice, on occasion.
If using your library without Rails really doesn't make sense at all, then you can also just use Rails.logger directly.
In either case, you're dealing with a standard Ruby Logger. Also keep in mind that, in theory, the logger may be nil.
We can use Rails logger directly into the lib, see the following snippet.
require 'logger'
Rails.logger.info "Hay..!!! Im in lib"
Rails.logger.debug "Debugging this object from Lib #{object.inspect}"
Rails.logger.error "This is an error..."
Related
I'm currently working on the GCP and deployed my rails app on the GCP instance.
I'm currently using https://github.com/brendeschuijmert/google-cloud-ruby/tree/master/google-cloud-logging for the compute engine.
When I use this on the rails application.
Rails.logger.info "Hello World" works well.
But logger.warn "Hola Mundo" is not working.
I want someone shade some light on this problem.
Thanks
If you're trying to call logger from outside of a controller/model or some other file that is a part of Rails' structure - you will have to explicitly create a logger for yourself with:
logger = Logger.new(STDOUT) # Or wherever you want to log to
However if Rails.logger is working, then you likely just need an alias like logger = Rails.logger to allow you to use logger.warn without the Rails namespace prefix. You're probably in a file that doesn't already have a helper that is aliasing that for you.
Some more digging in the API reveals that the logger stems from ActiveSupport::LogSubscriber - several classes like ActionController include child LogSubscribers that inherit from that module and hence have the logger method available to them. You can manually alias it to Rails.logger to have it work for you wherever you are trying to invoke it.
Source: https://api.rubyonrails.org/classes/ActiveSupport/LogSubscriber.html#method-c-logger
The question here asks how to extract Rails view helper functions into a gem, and the accept answer is pretty good.
I am wondering - how to do the same for Sinatra? I'm making a gem that has a bunch of helper functions defined in a module, and I'd like to make these functions available to Sinatra views. But whatever I try, I cannot seem to access the functions, I just get a undefined local variable or method error.
So far, my gem structure looks like this (other stuff like gemspec omitted):
cool_gem/
lib/
cool_gem/
helper_functions.rb
sinatra.rb
cool_gem.rb
In cool_gem.rb, I have:
if defined?(Sinatra) and Sinatra.respond_to? :register
require 'cool_gem/sinatra'
end
In helper_functions.rb, I have:
module CoolGem
module HelperFunctions
def heading_tag(text)
"<h1>#{text}</h1>"
end
# + many more functions
end
end
In sinatra.rb, I have:
require 'cool_gem/helper_functions'
module CoolGem
module Sinatra
module MyHelpers
include CoolGem::HelperFunctions
end
def self.registered(app)
app.helpers MyHelpers
end
end
end
This doesn't work. Where am I going wrong?
(And in case you're wondering, yes, I need the helper functions in a separate file. I plan to make the gem compatible with Rails as well, so I want to keep the functions isolated/de-coupled if possible).
You’re mainly just missing the call to Sinatra.register (in cool_gem/sinatra.rb):
require 'sinatra/base'
require 'cool_gem/helper_functions'
module CoolGem
# you could just put this directly in the CoolGem module if you wanted,
# rather than have a Sinatra sub-module
module Sinatra
def self.registered(app)
#no need to create another module here
app.helpers CoolGem::HelperFunctions
end
end
end
# this is what you're missing:
Sinatra.register CoolGem::Sinatra
Now any classic style Sinatra app that requires cool_gem will have the helpers available. If you use the modular style you’ll also need to call register CoolGem::Sinatra inside the Sinatra::Base subclass.
In this case, if you are just providing some helper methods, an easier way might be to just use the helpers method (again in cool_gem/sinatra.rb):
require 'sinatra/base'
require 'cool_gem/helper_functions'
Sinatra.helpers CoolGem::HelperFunctions
Now the methods will be available in classic style apps, and modular style apps will need to call helpers CoolGem::HelperFunctions. This is a bit simpler, but if you are adding methods to the DSL context you will need to use registered as above.
I would like to use the distance_of_time_in_words method in the date_helper.rb Rails file (see on Github) in an non-Rails Ruby project.
How can I include it? It requires other files, so how to include them?
I don't want to include all of Rails because that would slow down the development process.
Ruby 1.9.3
This method, distance_of_time_in_words is in actionpack/lib/action_view/helpers/date_helper.rb. So you should require 'action_view' and action_view/helpers to load this method. And the method is defined in module ActionView::Helpers::DateHelper, you can include it in your class. The method is an instance method.
require 'action_view'
require 'action_view/helpers'
class Klass
include ActionView::Helpers::DateHelper
end
c = Klass.new
c.distance_of_time_in_words( ...... )
If this is the only thing you want from it, then I'd just go take the source code and hack it to remove the dependencies (which appears to just be some I18n translations. To support the hack, you can probably translate this test suite.
Why would I do this instead of using the gem? Because it's just such an enormous dependency. It's so enormous that you actually notice it loading all that code. I'd rather rip out the method and hack it to work than depend on all of that (again, assuming this is the only thing you want from the lib).
So there's this great plugin I've gotten used to using in my Rails 2 projects called Bootstrapper. It essentially duplicates the functionality of the seeds.rb file, but I like it because it lets you break up your bootstrap process into concise chunks.
Anyway, I've gone so far as to fork the project and attempt to turn it into a Rails 3 gem. I've been able to get the gem to initialize and register the rake tasks and generators OK. However, I'm running into a problem with the Bootstrapper class itself. It won't load in the Rails project unless it's in a module.
That is, if I place the Bootstrapper class in a file by itself and require that file in my Railtie, then in my Rails app, it can't find the Bootstrapper class. If I put the class in a module and call Bootstrapper::Bootstrapper everything is peachy.
The code that actually requires the Bootstrapper class is this:
ActiveSupport.on_load :active_record do
require 'bootstrapper/bootstrapper'
end
The source is available here:
http://github.com/jrmehle/bootstrapper/tree/make_gem
Autoload paths actually has an annoying feature of following filesystem paths. For example in your lib or extras (depending on what you autoload) you might have the following file structure:
lib/bootstrapper/bootstrapper.rb
# in this case, Bootstrapper::Bootstrapper.class = Class in rails c
# ie: you don't get a NameError exception
More specifically,
lib/bootstrappers/bootstrapper.rb
# Bootstrapper::Bootstrapper => NameError
# Bootstrappers::Bootstrapper => works
If you really want the other way, you can move everything into your lib/bootstrapper.rb source file but meh, I don't like doing that, that's not how gems are organized. In rails3, you'll find the autoloading pretty nice once you use modules everywhere (which can be painful).
Rails3 uses /extras instead of /lib but it's not required, it's just the default (commented out) from rails new. To switch, you just autoload extras instead of lib.
I have a few methods I am adding to Ruby's Array class for my Rails application. Where is the best place to put them?
Right now I have them in config/environment.rb.
config/environment.rb isn't really the best place, since you can run into serious load ordering-problems if try to extend classes that haven't been resolved at the time environment.rb is executed.
Better to put a file into config/initializers. Any script placed there will be executed after the rails runtime is loaded.
What you could do is to create a file lib/my_extensions.rb
module MyExtensions
end
then in lib/my_extensions/array.rb :
module MyExtensions::Array
def join_with_commas
join(", ")
end
end
and in config/initializers/load_my_extensions.rb
class Array
include MyExtensions::Array
end
This will cause MyExtensions::Array to be auto-reloaded each time you invoke a request in development mode. This is nicer than restarting your application everytime you make a change to your code.
It would probably be cleaner to add a lib/ directory with all your extensions. Then add a line in config/environment.rb that loads the file:
require File.join(RAILS_ROOT, 'lib', 'array.rb')