Module: Substation

Defined in:

lib/substation.rb,
lib/substation/chain.rb,
lib/substation/request.rb,
lib/substation/version.rb,
lib/substation/response.rb,
lib/substation/chain/dsl.rb,
lib/substation/dsl/guard.rb,
lib/substation/processor.rb,
lib/substation/dispatcher.rb,
lib/substation/environment.rb,
lib/substation/dsl/registry.rb,
lib/substation/response/api.rb,
lib/substation/processor/nest.rb,
lib/substation/environment/dsl.rb,
lib/substation/chain/definition.rb,
lib/substation/chain/dsl/config.rb,
lib/substation/processor/config.rb,
lib/substation/response/failure.rb,
lib/substation/response/success.rb,
lib/substation/processor/builder.rb,
lib/substation/processor/wrapper.rb,
lib/substation/processor/executor.rb,
lib/substation/response/exception.rb,
lib/substation/processor/evaluator.rb,
lib/substation/processor/transformer.rb,
lib/substation/chain/dsl/module_builder.rb,
lib/substation/response/exception/output.rb,
lib/substation/processor/evaluator/result.rb,
lib/substation/processor/evaluator/handler.rb

Overview

Substation can be thought of as a domain level request router. It assumes that every usecase in your application has a name and is implemented in a dedicated class that will be referred to as an action in the context of substation. The only protocol such actions must support is ‘#call(request)`.

The contract for actions specifies that when invoked, actions can receive arbitrary input data which will be available in request.input. Additionally, request.env contains an arbitrary object that represents your application environment and will typically provide access to useful things like a logger or a storage engine abstraction.

The contract further specifies that every action must return an instance of either Substation::Response::Success or Substation::Response::Failure. Again, arbitrary data can be associated with any kind of response, and will be available in response.data. In addition to that, response.success? is available and will indicate wether invoking the action was successful or not.

Substation::Dispatcher stores a mapping of action names to the actual objects implementing the action. Clients can use ‘Substation::Dispatcher#call(name, input, env)` to dispatch to any registered action. For example, a web application could map an http route to a specific action name and pass relevant http params on to the action.

Defined Under Namespace

Modules: DSL, Processor Classes: AlreadyRegisteredError, Chain, Dispatcher, DuplicateProcessorError, Environment, Error, Request, ReservedNameError, Response, UnknownActionError, UnknownProcessor

Constant Summary

Undefined =

Represent an undefined argument

Object.new.freeze

EMPTY_ARRAY =

An empty frozen array useful for (default) parameters

[].freeze

EMPTY_HASH =

An empty frozen hash useful for (default) parameters

{}.freeze

VERSION =

Gem version

'0.0.11'.freeze