In Rails, if "gem install ___" installs 6 gems total, will installing as plugin require installing the other 5 gems manually?

Question

If installing a gem using

gem install ______

actually install 6 gems, because of the dependencies, then if the gem is installed as plugin by

script/plugin install git://github.com/author/____.git

or

script/plugin install _____

then we to manually install the gem it depends on?

Does it matter if it is the later form, where it doesn't get it from github?

Answer 1

If you're worried about gems and dependencies, plugins are probably not the way to go. I would recommend checking out Bundler. It allows you to lock your gem versions and makes it really easy to manage gem sets across multiple servers, and developers.

Answer 2

Plugins are supposed to include their own dependencies inside them so you'll have:

# my_rails_project/vendor/plugins/thatfancyplugin/vendor/<their dependencies>

If the plugin you're looking at includes those other gems inside the repo, you'll be fine to just install the plugin. I expect it doesn't though which would require you to explicitly define the requirements in your config/environment.rb file.

It's for this reason that I'd recommend using it as a gem, because then you don't have to manually specify requirements that shouldn't be concerning you. A number of plugins have changed their recommended installation instructions telling people to install as a gem instead of a plugin, which is I expect mostly for this reason.