How does bundler work?
bundler, ruby, ruby-on-rails, ruby-on-rails-3, rubygems
Solution
They key is actually in how Rails is set up out of the box. Which is also one of the reasons Rails is so slow to start on larger projects.[1]
In boot.rb you'll find:
require 'bunder/setup'
and at the top of application.rb you'll find:
Bundler.require(:default, :development)
This last method call looks back to your Gemfile, then iterates all of the gems that are in the given groups (`:default` and `:development` in the above). It then takes a stab at determining what the default file is that should be loaded, which is typically the gem name, but can also be specified by a `:require` option. Bundler has some built-in naming convention exceptions too, such as the handling of "-" instead of "_".
Bundler then just loads the primary file for the gem, which in turn (typically) loads the files inside the gem.
The `'bundler/setup'` file performs `Bundler.setup`, which takes care of the load path. It prepends (unshifts) to the `$LOAD_PATH` for each gem. The actual information about what those loads paths should be comes from rubygems.
Take a look at the source in:
https://github.com/carlhuda/bundler/blob/master/lib/bundler/setup.rb https://github.com/carlhuda/bundler/blob/master/lib/bundler/runtime.rb
[1]: When you start a new Rails project, you'll probably find it doesn't get so slow over time if you delete the Bundler.require line and just require gems as they are needed.
Problem
This question is about bundler,rubygems & how does it figure out which method I am calling. Its quite long, so please bear with me. As per my understanding, Bundler is a dependency management tool for managing gems for ruby. It install all the gems & their dependencies listed in the `Gemfile`. The question I want to ask can be best illustrated by an example. so here--> In my rails app I am doing this in my controller:- ``` module SurveyorControllerCustomMethods def create super end end class SurveyorController < ApplicationController include Surveyor::SurveyorControllerMethods end ``` Here, I am doing two things: - Include `SurveyorControllerMethods` from Surveyor gem. - As I have used super here, it would call `create` method from `SurveyorControllerMethods` which works just fine but I do not understand it. and the gem is installed at ``` $ bundle show surveyor /home/gaurish/.rvm/gems/ruby-1.9.3-p194/gems/surveyor-0.22.0 ``` Which surprisingly is NOT present in ruby's `$LOAD_PATH`. so question is: - how does it even work? - Install a gem using bundler, what happens behind the scenes during install? - there are some gems ex `jquery-rails` for which we even don't have to include/call them in our code & yet, jQuery JavaScript file is automatically included. I know its not magic, so how does this work?