Rabl::Extend::Compiler

Add this line to your application's Gemfile:

gem 'rabl-extend-compiler'

And then execute:

$ bundle

Or install it yourself as:

$ gem install rabl-extend-compiler

When using Rabl there is a DSL method called extend which embeds another template in the current template and serves as a mechanism to be DRY and maintain object definitions in a single place.

One signficant downsie of such a pattern is that the template rendering for large number of collections can be significantly lower (we have measured from 10-25% slower on collections up to 1000 objects)

In order to help facilitate still using Rabl (it's a great library) we dediced to write a few rake tasks that allow us the benefits of then extension system without the drawbacks. Attempting to emulate something like what is mentioned in this issue and running rake tasks to verify or compile the extensions before moving to production.

This gem merely outlines the components and they may be used as you see fit at varying times in your infrastructure (we run the verification rake task in our CI pipeline)

The rake tasks are:

rake rabl:extend:compiler:all Runs all steps

rake rabl:extend:compiler:reset Will reset all signatures from the extended files

rake rabl:extend:compiler:compile Will compile and sign each use of extend in the code base

rake rabl:extend:compiler:verify Will exit(1) if the extensions are not compiled or the signatures do not match on the compiled extensions

The "signatures" encompass the attributes or files from an extension and are merely a SHA256 digest of the file contents during the compilation step and creates an easy and fast mechanism to determine if the extended files have been altered without updating the extensions.

The rake tasks above will create the signature and file below when extending anther file (check spec directory for more examples)

# rabl-extend-compiler extends "extend"   => 9ebbe5e06dc6163365ca3d550b757464f0cdfe4b4227a7d52d4e6c1cc11af484
#
# This file segment is generated by rabl-extend-compiler rake task
# and should not be edited. To edit the generated extension
# edit the file at: ["extend"]
attributes :id, :derp, :body
# 9ebbe5e06dc6163365ca3d550b757464f0cdfe4b4227a7d52d4e6c1cc11af484

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/rabl-extend-compiler.