Class: Interactor::Context

Inherits:
OpenStruct
  • Object
show all
Defined in:
lib/interactor/context.rb

Overview

Public: The object for tracking state of an Interactor's invocation. The context is used to initialize the interactor with the information required for invocation. The interactor manipulates the context to produce the result of invocation.

The context is the mechanism by which success and failure are determined and the context is responsible for tracking individual interactor invocations for the purpose of rollback.

The context may be manipulated using arbitrary getter and setter methods.

Examples

context = Interactor::Context.new
# => #<Interactor::Context>
context.foo = "bar"
# => "bar"
context
# => #<Interactor::Context foo="bar">
context.hello = "world"
# => "world"
context
# => #<Interactor::Context foo="bar" hello="world">
context.foo = "baz"
# => "baz"
context
# => #<Interactor::Context foo="baz" hello="world">

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.build(context = {}) ⇒ Object

Internal: Initialize an Interactor::Context or preserve an existing one. If the argument given is an Interactor::Context, the argument is returned. Otherwise, a new Interactor::Context is initialized from the provided hash.

The “build” method is used during interactor initialization.

context - A Hash whose key/value pairs are used in initializing a new

Interactor::Context object. If an existing Interactor::Context
is given, it is simply returned. (default: {})

Examples

context = Interactor::Context.build(foo: "bar")
# => #<Interactor::Context foo="bar">
context.object_id
# => 2170969340
context = Interactor::Context.build(context)
# => #<Interactor::Context foo="bar">
context.object_id
# => 2170969340

Returns the Interactor::Context.


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# File 'lib/interactor/context.rb', line 55

def self.build(context = {})
  self === context ? context : new(context)
end

Instance Method Details

#_calledObject

Internal: An Array of successfully called Interactor instances invoked against this Interactor::Context instance.

Examples

context = Interactor::Context.new
# => #<Interactor::Context>
context._called
# => []

context = MyInteractor.call(foo: "bar")
# => #<Interactor::Context foo="baz">
context._called
# => [#<MyInteractor @context=#<Interactor::Context foo="baz">>]

Returns an Array of Interactor instances or an empty Array.


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# File 'lib/interactor/context.rb', line 177

def _called
  @called ||= []
end

#called!(interactor) ⇒ Object

Internal: Track that an Interactor has been called. The “called!” method is used by the interactor being invoked with this context. After an interactor is successfully called, the interactor instance is tracked in the context for the purpose of potential future rollback.

interactor - An Interactor instance that has been successfully called.

Returns nothing.


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# File 'lib/interactor/context.rb', line 137

def called!(interactor)
  _called << interactor
end

#fail!(context = {}) ⇒ Object

Public: Fail the Interactor::Context. Failing a context raises an error that may be rescued by the calling interactor. The context is also flagged as having failed.

Optionally the caller may provide a hash of key/value pairs to be merged into the context before failure.

context - A Hash whose key/value pairs are merged into the existing

Interactor::Context instance. (default: {})

Examples

context = Interactor::Context.new
# => #<Interactor::Context>
context.fail!
# => Interactor::Failure: #<Interactor::Context>
context.fail! rescue false
# => false
context.fail!(foo: "baz")
# => Interactor::Failure: #<Interactor::Context foo="baz">

Raises Interactor::Failure initialized with the Interactor::Context.

Raises:


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# File 'lib/interactor/context.rb', line 123

def fail!(context = {})
  context.each { |key, value| self[key.to_sym] = value }
  @failure = true
  raise Failure, self
end

#failure?Boolean

Public: Whether the Interactor::Context has failed. By default, a new context is successful and only changes when explicitly failed.

The “failure?” method is the inverse of the “success?” method.

Examples

context = Interactor::Context.new
# => #<Interactor::Context>
context.failure?
# => false
context.fail!
# => Interactor::Failure: #<Interactor::Context>
context.failure?
# => true

Returns false by default or true if failed.

Returns:

  • (Boolean)

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# File 'lib/interactor/context.rb', line 97

def failure?
  @failure || false
end

#rollback!Object

Public: Roll back the Interactor::Context. Any interactors to which this context has been passed and which have been successfully called are asked to roll themselves back by invoking their “rollback” instance methods.

Examples

context = MyInteractor.call(foo: "bar")
# => #<Interactor::Context foo="baz">
context.rollback!
# => true
context
# => #<Interactor::Context foo="bar">

Returns true if rolled back successfully or false if already rolled back.


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# File 'lib/interactor/context.rb', line 155

def rollback!
  return false if @rolled_back
  _called.reverse_each(&:rollback)
  @rolled_back = true
end

#success?Boolean

Public: Whether the Interactor::Context is successful. By default, a new context is successful and only changes when explicitly failed.

The “success?” method is the inverse of the “failure?” method.

Examples

context = Interactor::Context.new
# => #<Interactor::Context>
context.success?
# => true
context.fail!
# => Interactor::Failure: #<Interactor::Context>
context.success?
# => false

Returns true by default or false if failed.

Returns:

  • (Boolean)

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# File 'lib/interactor/context.rb', line 76

def success?
  !failure?
end