Class: Jets::Klass

Inherits:
Object
  • Object
show all
Defined in:
lib/jets/klass.rb

Overview

Loading a class can usually be loaded via .constantize. But app/functions files are anonymous ruby classes created with Class.new. Anonymous classes cannot be loaded via .constantize and go through standard autoloading.

Jets::Klass provides a way to load app classes in app/controllers, app/jobs, app/functions in a consistent way without having to worry about the anonymous class loading quirk. Classes that are not anonymously defined like controllers and jobs are loaded via autoloading with .constantize. Anonymously defined classes like functions are loaded via Object.const_set.

Examples:

Jets::Klass.from_path("app/controllers/posts_controller.rb")
Jets::Klass.from_path("app/jobs/hard_job.rb")
Jets::Klass.from_path("app/functions/hello.rb")
Jets::Klass.from_path("app/functions/hello_function.rb")

Jets::Klass.from_task(task)

The from_task method takes a Jets::Lambda::Task as an argument and is useful for the CloudFormation child stack generation there the registered task info is available but the path info is now.

Constant Summary collapse

@@loaded_anonymous_classes = 
[]

Class Method Summary collapse

Class Method Details

.class_name(path) ⇒ Object

app/controllers/posts_controller.rb => PostsController



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# File 'lib/jets/klass.rb', line 39

def class_name(path)
  path.sub(%r{.*app\/(.*?)/},'').sub(/\.rb$/,'').classify
end

.from_path(path) ⇒ Object

from_path allows us to load any app classes in consistent way for app/controllers, app/jobs, and app/functions.



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# File 'lib/jets/klass.rb', line 28

def from_path(path)
  class_name = class_name(path)

  if path.include?("/functions/") # simple function
    load_anonymous_class(class_name, path)
  end

  class_name.constantize # autoload or nothing if load_anonymous_class called
end

.from_task(task) ⇒ Object 



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# File 'lib/jets/klass.rb', line 43

def from_task(task)
  class_name = task.class_name
  filename = class_name.underscore

  # Examples of filename: posts_controller, hard_job, security_rule,
  #   hello_function, hello
  valid_types = %w[controller job rule]
  type = filename.split('_').last
  type = "function" unless valid_types.include?(type)

  path = "app/#{type.pluralize}/#{filename}.rb"
  from_path(path)
end

.load_anonymous_class(class_name, path) ⇒ Object 



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# File 'lib/jets/klass.rb', line 58

def load_anonymous_class(class_name, path)
  constructor = Jets::Lambda::FunctionConstructor.new(path)
  # Dont load anonyomous class more than once to avoid these warnings:
  #   warning: already initialized constant Hello
  #   warning: previous definition of Hello was here
  unless @@loaded_anonymous_classes.include?(class_name)
    # use class_name as the variable name for prettier class name.
    Object.const_set(class_name, constructor.build)
    @@loaded_anonymous_classes << class_name
  end
end