Class: FService::Result::Failure

Inherits:
Base
  • Object
show all
Defined in:
lib/f_service/result/failure.rb

Overview

Represents a value of a failed operation. The error field can contain any information you want.

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Base

#on

Constructor Details

#initialize(error) ⇒ Failure

Creates a failed operation. You usually shouldn’t call this directly. See Base#failure.

Parameters:

  • error (Object) —

    failure value.



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# File 'lib/f_service/result/failure.rb', line 20

def initialize(error)
  @error = error
  freeze
end

Instance Attribute Details

#error ⇒ Object (readonly)

Returns the provided error



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# File 'lib/f_service/result/failure.rb', line 14

def error
  @error
end

Instance Method Details

#failed? ⇒ Boolean

Returns true.

Examples:

# Suppose that User::Update returns an FService::Result

log_errors(user) if User::Update.(user: user).failed?

Returns:

  • (Boolean) 


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# File 'lib/f_service/result/failure.rb', line 43

def failed?
  true
end

#successful? ⇒ Boolean

Returns false.

Examples:

# Suppose that User::Update returns an FService::Result

log_errors(user) unless User::Update.(user: user).successful?

Returns:

  • (Boolean) 


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# File 'lib/f_service/result/failure.rb', line 32

def successful?
  false
end

#then ⇒ self

Returns itself to the given block. Use this to chain multiple service calls (since all services return Results). It will short circuit your service call chain.

Examples:

class UsersController < BaseController
  def create
    result = User::Create.(user_params) # if this fails the following calls won't run
              .then { |user| User::SendWelcomeEmail.(user: user) }
              .then { |user| User::Login.(user: user) }

    if result.successful?
      json_success(result.value)
    else
      json_error(result.error)
    end
  end
end

Returns:

  • (self) 


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# File 'lib/f_service/result/failure.rb', line 79

def then
  self
end

#to_s ⇒ String

Outputs a string representation of the object

Examples:

puts FService::Result::Failure.new("Oh no!")
# => Failure("Oh no!")

Returns:

  • (String) —

    the object’s string representation



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# File 'lib/f_service/result/failure.rb', line 91

def to_s
  error.nil? ? 'Failure()' : "Failure(#{error.inspect})"
end

#value ⇒ Object

Failed operations do not have value.



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# File 'lib/f_service/result/failure.rb', line 48

def value
  nil
end

#value! ⇒ Object

Raises an exception if called. (see #value)

Raises:



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# File 'lib/f_service/result/failure.rb', line 54

def value!
  raise Result::Error, 'Failure objects do not have value'
end