Designing an app is an opportunity to explore strange new worlds and boldly go where no one has gone before. But before you set off into space, you need to create some boilerplate code. The initial setup of an application can be daunting and tedious, but it’s necessary to get your app up and running. So how do you go from idle to warp speed in development? Ruby generators! Ruby on Rails provides an extensive list of generators that will write core application functionality code for you. That means development will be faster and more consistent, and you will not need to worry about memorizing repetitive code. This is a powerful tool for any Ruby developer.
Model and Controller (The Shuttlecraft)
To explain Ruby generators, I would like to share some common and valuable generators I used to create my Starfinder Companion App. Some of the first generators I used were model and controller. It is very easy to type these commands in your terminal. Say I wanted to create my Starship model. I would write $ rails generate model Starship name:string tier:string. This would generate a Starship Model file, a database starships table with a name and a tier column, and some associated tests. The model generator creates only a few necessary files to give you maximum flexibility. You can also save time by typing “g” instead of “generate” and omitting “string,” as string is the default type: $ rails g model Starship name tier. A controller generator is similar with the emphasis on controller. If I generated $ rails g controller Starship index, I would get a Starship controller with an index method, routes for each action (in this case index route), and corresponding starships view folder and helper files. It would not generate a model or table migration. Both are useful options, but wouldn’t it be nice if we could generate all of the above simultaneously? As it turns out, you can!
Resource (The USS Enterprise)
My personal favorite generator for Starfinder Companion was $ rails g resource, which I like to call the Swiss Army knife of Ruby generators. With that simple command, a model, controller, database table, view directory, helper directory, test suite, and styling files are created within seconds. When I added starships to my application, I added the command line $ rails g resource Starship name tier, and I was all set to start coding. I could start thinking about how starships related to other models and how the user would interact with starships. This generator saved me significant time, freeing me up to put my energy towards figuring out the purpose of my app.
Generators and Beyond
There is one more specific generator I used often in my Starfinder app that I would like to share: $ rails g migration. This handy command will create or alter a table in your database and will automatically assign it a timestamp. Here are some examples of common migrations I used:
$ rails g migration CreateCharacters name - This created a characters table with a name column with a string type.
$ rails g migration AddUserIdToCampaigns user_id:integer - This added a user_id column with an integer type to the campaigns table.
$ rails g migration RemoveStatusFromCampaigns status:Boolean - This removed the status column with a Boolean type from the campaigns table.
As you can see, there are many options for generating migrations, and I highly recommend practicing creating tables and altering columns this way to make you a more efficient programmer.
The one generator I did not use and would advise against is the $ rails generate scaffold. This command will create a full set of MVC code and lots of unused code/directories. Although this command can instantly get your app running, you will most likely spend more time going through all the unnecessary code then if you just wrote the boilerplate code yourself. It may also cause excessive bugs and headaches later on. Also, all the generator commands mentioned were used after the initial $ rails new which you should use to create an entire rails directory structure.
Now you understand all of the Rails generators, and the ship is ready to take off! Well, not quite. There are numerous generators, including custom-made generators through RubyGems. You can also create your own! For example, $ rails destroy is the opposite of rails generate and will destroy any generation you don’t need anymore.
With Ruby on Rails generators, you will no longer be left in the cornfields looking up at the stars. The speed and efficiency of $ rails g will take your application to the final frontier.