Class: Langis::Rackish::RackishJob

Inherits:
Struct
  • Object
show all
Defined in:
lib/langis/rackish.rb

Overview

RackishJob is a dual DelayedJob-Resque job that is used to execute Rackish applications, or Rack applications that are robust against non-conformant “Rack Environments”, in the background. Rackish Applications are created and registered with this RackishJob class. Each registration is associated with an app_key that is well known to any component that wants to execute that particular Rackish Application. Client components then queue up this job class with the app_key and the input hash for that application.

Notes

  • This class does not provide a compliant Rack specified environment to the Rackish applications it calls. Prepend middleware that provides such an environment to the application chain if required.

For example, to queue up a RackishJob using DelayedJob:

Delayed::Job.enqueue Langis::Rackish::RackishJob.new(
  'my_app',
  {
    'input_key' => 'value'
  })

For example, to queue up a RackishJob using Resque:

Resque.enqueue(
  Langis::Rackish::RackishJob,
  'my_app',
  {
    'input_key' => 'value'
  })

The my_app job may be registered in the worker process as follows:

Langis::Rackish::RackishJob.register_rackish_app(
  'my_app',
  lambda { |env|
    # Do something
  })

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#app_key ⇒ Object

Returns the value of attribute app_key

Returns:

  • (Object) —

    the current value of app_key



49
50
51
 
# File 'lib/langis/rackish.rb', line 49

def app_key
  @app_key
end

#env ⇒ Object

Returns the value of attribute env

Returns:

  • (Object) —

    the current value of env



49
50
51
 
# File 'lib/langis/rackish.rb', line 49

def env
  @env
end

Class Method Details

.perform(app_key = nil, env = {}) ⇒ Object

Acts as the Resque starting point.

For example, the following can be used to execute the ‘my_app’ Rackish application using Resque from an ActiveRecord callback:

def after_create(record)
  Resque.enqueue RackishJob, 'my_app', { 'my.data' => record.id }
end

Parameters:

  • app_key (String) (defaults to: nil) —

    The registered application’s name that is to be called with the given env input.

  • env (Hash) (defaults to: {}) —

    The Rackish input environment. This is the input that should be relevant to the called app. There is no guarantee that this environment hash is a fully compliant Rack environment.

Raises:

  • (RackishAppNotFoundError) —

    Signals that the given app_key was not registered with RackishJob. See DelayedJob and Resque documentation to understand how to ignore or handle raised exceptions for retry.



91
92
93
94
95
96
97
98
 
# File 'lib/langis/rackish.rb', line 91

def perform(app_key=nil, env={})
  app = @apps[app_key]
  if app.respond_to? :call
    app.call env 
  else
    raise NotFoundError.new "#{app_key} not found"
  end
end

.register_rackish_app(app_key, app) ⇒ #call

Registers a Rackish Application under a given name so it can be executed by the RackishJob class via the DelayedJob or Resque background job libraries.

For example, the following can be found in a Rails initializer.

my_app = Rack::Builder.app do
  run MyApp
end
RackishJob.register 'my_app', my_app

Parameters:

  • app_key (String) —

    The name used to lookup which Rackish application to call.

  • app (#call) —

    The Rackish Application to call for the requested app_key.

Returns:

  • (#call) —

    The Rackish Application passed in is returned back.



68
69
70
71
 
# File 'lib/langis/rackish.rb', line 68

def register_rackish_app(app_key, app)
  @apps ||= {}
  @apps[app_key.to_s] = app
end

Instance Method Details

#perform ⇒ Object

Acts as the DelayedJob starting point. All this does is relays the call to the Resque starting point.

For example, the following can be used to execute the ‘my_app’ Rackish application using DelayedJob from an ActiveRecord callback:

def after_create(record)
  Delayed::Job.enqueue(
    RackishJob.new('my_app', { 'my.data' => record.id }))
end

See Also:



113
114
115
 
# File 'lib/langis/rackish.rb', line 113

def perform
  self.class.perform(app_key.to_s, env || {})
end