I'm working on a gem that for now just requires a handful of other gems. The problem I'm running into is that the mutant gem needs to be required after the other two, but when I add my gem to a Gemfile in a Rails project, mutant loads before the other two. How can I make it so that when my gem is required, that the other two gems are loaded first?
IIRC, they are loaded in the order they are listed withing your gemfile. Add mutant after the gems you want loaded first.
Related
I would like to use gems 'better_errors' and 'binding_of_caller' for my debugging in rails app, but i DON'T want to include those in Gemfile. Is it possible to do? My first thought was to simply
gem install better_errors
gem install binding_of_caller
but it doesnt work, i mean installation finishes without problems, but thats it, gem doesnt seem to work at all when i run my app on localhost. Do I need some kind of config set, anybody?
but i DON'T want to include those in Gemfile. Is it possible to do?
Yes, it is possible. You can just download the respective directories in desire folder (ex. lib) and add that gem class in your initializer so it will be loaded at the time of starting. Configuration varies as per gem.
My first thought was to simply .... but it doesnt work,
Ofcourse, it wont. How can your rails app magically detects without knowing it that you have better way to show error. It is simply saying like you have cancer formula and doctors automatically applied that formula to there patient without you telling them. There should be some commucaition between two parties rails-app and gem so they can coordinate and work better.
Do I need some kind of config set, anybody?
Yes, explained above.
i dont want to force those gems on my coworkers. KRUKUSA any more details? // said in comment
Yes, including this gems in your rails app can do this job. This extension will be available automatically to your worked. (no force applied :P)
it looks like all you want to not show those gems to other co-worker, if so, you can use this trick with git.
To achieve this thing, first simply add the gems in your gemfile, run bundle and then make it untrackable with git. You can put Gemfile and Gemfile.lock in your .gitignore file. or you can add the first add the gems and mark it ignore with below command. Read more here
git update-index --assume-unchanged Gemfile Gemfile.lock
Another possibility would be to create your own environment and use it accordingly.
Have your own configuration for myenv:
$ cp config/environments/{development,myenv}.rb
In config/database.yml, add the environment myenv and use the same config as development:
development: &development
<rest of the code you have on config/databases.yml>
...
myenv:
<< *development
In Gemfile add your custom gems to use on your mydev group:
group :myenv do
gem 'better_errors'
gem 'binder_of_caller'
end
Run rails and rake with RAILS_ENV like this: RAILS_ENV=myenv rails c
The advantage of this approach is that you still get the updates from Gemfile from the repo, and if you need to add a gem in the Gemfile for everybody to see, you still can.
Also, nobody will see the gems you installed inside the myenv group in your Gemfile.
Ruby is so darn mysterious when it comes to using the gems! Where do these gems reside?? In java, you can have as many jars you want just include them in your CLASSPATH and your good to go. Ruby is a simpler language, but why do I need the headache of dealing with simple crap? Can anyone seriously finally explain how the gem loading process works? It seems like no one really knows why the heck do requiring some gems work, and requiring others doesn't even if you have gem installed them and they are in the gem list. Where is the authority in ruby on this site that can finally clarify the gem loading process.
I am tried of including 'rubygems' in my ruby scripts to prevent errors like LoadError: no such file to load -- pony
And even when I do require 'rubygems' in my scripts, it still gives LoadErrors. Even if the gem is in my gem list.
When you're using Bundler to manage Gems in your project (you will have a Gemfile at the root directory of the project), be sure to run
bundle install
requiring rubygems just loads rubygems itself (and isn't required in ruby 1.9 and above)
You need to actually load each gem individually via require.
If you use bundler, then you can optionally have bundle auto require everything from your Gemfile
I am wondering how the initialization process works with Gems. Basically, I ran into an issue today when I tried to call a constant, that lives in my Rails application from a Gem that I have included in my rails project.
The constant is Air::Fly
The constant loads fine from Rails, but the Gem can not load this constant. My goal was to extend the Rails Application class from the context of the Gem, in order to make my code more modular.
How can I load a rails application class from a Gem?
Bundler resolves the dependencies of gems by checking the gemspec file for runtime dependencies. If a gem X's gemspec has add_runtime_dependency "Y", then gem Y will be loaded before gem X.
So, assuming Air is a gem, in your case, you need to add to your gemspec:
s.add_runtime_dependency "air"
This will ensure it's available for use inside your own gem ;)
Our team uses different databases for each other, and we are using bundler so our Gemfile contains the repo creator's db connector(mysql)
I am using pg and due to a bit laziness and fear of breaking something, I don't want to use mysql, so I just add a gem "pg" in our Gemfile.
Of course, since we're using git, it will always show as a modified file, and we all use the Gemfile so we can't gitignore it or commit it with our changes.
Question is, how do we go about this? Is there a conditional in bundler or do I just have to declare that I'm using a certain gem someplace else?
Since Gemfile, like Rakefile, is just a chunk of Ruby, you can throw in conditionals if you think it will simplify your life. For instance:
if (Gem.available?('pg'))
gem 'pg'
else
gem 'mysql2'
end
Sometimes you have to do this for different Ruby versions as 1.8 and 1.9 sometimes need different gems.
You can use a group. Yehuda Katz explain it how here (taking in example the pg gem) http://yehudakatz.com/2010/05/09/the-how-and-why-of-bundler-groups/
Let's say in a Rails app you have some gems that you use in your app (we'll call them "primary gems") and you have vendored them for portability.
Let's say that those "primary gems" also require gems of their own - we'll call these "secondary gems".
When you are setting up your environment.rb, you have to say:
config.gem 'primary-gem'
for any of the gems you are using directly.
But, do you also need to say . . .
config.gem 'secondary-gem'
even if you are not using that gem explicitly in your app?
Or is it simply enough to include the gem in your vendor/gems directory for it to get picked up by your app?
At deploy time rails knows about your dependencies, so if you want to freeze your gems then you can run
rake gems:unpack:dependencies
to freeze them into the vendor directory.
At runtime however it's the gems job to load it's dependencies, and usually the gems do this, so a config.gem 'primary' should work.
No, you don't or at least you shouldn't. Each GEM specification should include it's own list of dependencies. When primary gem is installed, RubyGems automatically will install each gem dependency on cascade.
In other words, if A requires B that requires C+D, you only need to write
config.gem 'A'
When the command
gem install A
is run, RubyGems will resolve all the dependencies and install them.
You can view all A dependencies running (from a Rails project)
rake gems
Sometimes, a GEM author may forget to include some GEM dependencies in the specification. In this case you should specify them in your environment.rb to force the application to install them. Off course, it's also a good idea to contact the GEM maintainer so that it can fix the problem.