Module: Cuprum::Operation::Mixin

Included in:

BuiltIn::IdentityOperation, BuiltIn::NullOperation, Cuprum::Operation

Defined in:

lib/cuprum/operation.rb

Overview

Module-based implementation of the Operation methods.

Use this to convert an already-defined command into an operation.

Examples:

class CustomOperation < CustomCommand
  include Cuprum::Operation::Mixin
end

Instance Attribute Summary

• #result ⇒ Cuprum::Result readonly

  The result from the most recent call of the operation.

Instance Method Summary

• #call(*arguments, **keywords) { ... } ⇒ Cuprum::Operation

  Calls the command implementation and stores the result.

• #called? ⇒ Boolean

  True if the operation has been called and has a reference to the most recent result; otherwise false.

• #error ⇒ Object

  The error (if any) from the most recent result, or nil if the operation has not been called.

• #failure? ⇒ Boolean

  True if the most recent result had an error, or false if the most recent result had no error or if the operation has not been called.

• #reset! ⇒ Object

  Clears the reference to the most recent call of the operation, if any.

• #status ⇒ Symbol^?

  The status of the most recent result, or nil if the operation has not been called.

• #success? ⇒ Boolean

  True if the most recent result had no error, or false if the most recent result had an error or if the operation has not been called.

• #to_cuprum_result ⇒ Cuprum::Result

  The most recent result if the operation was previously called; otherwise, returns a failing result with a Cuprum::Errors::OperationNotCalled error.

• #value ⇒ Object

  The value of the most recent result, or nil if the operation has not been called.

Instance Attribute Details

#result ⇒ Cuprum::Result (readonly)

# File 'lib/cuprum/operation.rb', line 51

def result
  @result
end

Instance Method Details

#call(*arguments, **keywords) { ... } ⇒ Cuprum::Operation

Calls the command implementation and stores the result.

Yields:

• If a block argument is given, it will be passed to the implementation.

See Also:

• Command#call

# File 'lib/cuprum/operation.rb', line 66

def call(*args, **kwargs, &)
  reset! if called? # Clear reference to most recent result.

  @result = super

  self
end

#called? ⇒ Boolean

# File 'lib/cuprum/operation.rb', line 76

def called?
  !result.nil?
end

#error ⇒ Object

# File 'lib/cuprum/operation.rb', line 82

def error
  called? ? result.error : nil
end

#failure? ⇒ Boolean

# File 'lib/cuprum/operation.rb', line 89

def failure?
  called? ? result.failure? : false
end

#reset! ⇒ Object

Clears the reference to the most recent call of the operation, if any. This allows the result and any referenced data to be garbage collected. Use this method to clear any instance variables or state internal to the operation (an operation should never have external state apart from the last result).

If the operation cannot be run more than once, this method should raise an error.

# File 'lib/cuprum/operation.rb', line 101

def reset!
  @result = nil
end

#status ⇒ Symbol^?

# File 'lib/cuprum/operation.rb', line 107

def status
  called? ? result.status : nil
end

#success? ⇒ Boolean

# File 'lib/cuprum/operation.rb', line 114

def success?
  called? ? result.success? : false
end

#to_cuprum_result ⇒ Cuprum::Result

# File 'lib/cuprum/operation.rb', line 121

def to_cuprum_result
  return result if result

  error = Cuprum::Errors::OperationNotCalled.new(operation: self)

  Cuprum::Result.new(error:)
end

#value ⇒ Object

# File 'lib/cuprum/operation.rb', line 131

def value
  called? ? result.value : nil
end