BundleGem: A Gem Project Generator with User Defined Templates

The goal of the project is to allow users to define templates in the most native form to all technologist: Directory Structures, short commands, and helpful commands which make the gem's usage completely visible!

The benefits of using this repo to create gems rather than bundler is that you can choose to create 'classes' of gems. By classes, I mean that there are different types of 'gems', there are basic library gems, that are just code and can only be used from other code, there are command line application gems, those are gems that are run on the command line and include a binary file, and there are also web interface gems, those are gems which spin up a simple web interface and request that the user connect to it's server on what ever port it has spun up on. Depending on your field of specialty, you may be able to imagine other classes of gems that will aid you in your work.

All of these 'classes of gems' as I refer to them, start out with a different code base, consistent with all other gems of the same class. This 'class based' approach to gem creation is different from the adaptive approach that other gem generators are based on.

The most beneficial aspect of this gem is that it allows you to specify exactly how you want your 'default starting gem' to look, rather than rely on what someone else thought would be generally helpful.

First install it:

gem install bundlegem

Configuration comes from your gitconfig. At the user level, this is set at ~/.gitconfig. These are the recommended minimal configurations to get the default templates to work ok:

[user]
  email = me@example.com
  name = Me
  repo-domain = github.com

These commands will create a new gem named project_name in /tmp/project_name:

$  cd /tmp
$  bundlegem project_name -t arduino

$  bundlegem --list
PREDEFINED:
  default - A basic ruby gem
  service - A gem that allows installation as a service to run as a daemon

MISC:
  my_service -

EMBEDDED:
  arduino

You'll find a project skeleton in ~/.bundlegem/templates/my_service that you can customize to your liking.

You can create a new template for a project class you expect to use more than once:

$  bundlegem --newtemplate
Specify a name for your gem template:  my_service
Specify description:
Specify template tag name [MISC]:
Cloning base project structure into ~/.bundlegem/templates/my_service
...
  Complete!

You can now get to work making changes to the my_service gem. All you need to know is that any file that ends in .tt in that folder will be copied into new projects when you create a new project based on that template, however the .tt extension will obviously be stripped out of the resulting file name.

Also, you can specify the category of the gem by editing the .bundlegem file in each template's root. Categories are just used for organizing the output when you run bundlegem --list. Here, I'll show you an example:

Place your own templates in ~/.bunglegem/templates. You can populate it with examples by running bundlegem --install-best-templates which will effectively clone down a few sample git repos into the templates folder for you such as Go-Cli for instance.

You'll get a good idea as to the possibilities by inspecting the files in templates. Check out the reference test file to see what kind of interpolations are possible.

Quick Tips:

• Files ending with a .tt extension will by written to new projects
• File names containing #{name} will have that symbol replaced by the project name defined on the CLI
• Within files, use <%=config[:namespaced_path]%> to have that reinterpreted as just the file name with underscores
• Have a look under the hood to see other options and the context where the ERB.new takes place.

A lot of the code here was extracted from Bundler's bundle gem command, so credits to the Bundler folks. Originally I planned to make the new features accessible to the Bundler team and went out of my way to keep the code as similar to their project as possible, but ultimately realized two thing. First they don't want to grow the project creation feature because good tools should do a single thing very well (manage dependencies), not many things (manage dependencies and also do random other helpful stuff). And second Bundler is a profoundly common dependency meaning every change is enormously high stakes.