Class: Promise

Inherits:
Object
  • Object
show all
Includes:
Progress
Defined in:
lib/promise.rb,
lib/promise/group.rb,
lib/promise/version.rb,
lib/promise/callback.rb,
lib/promise/progress.rb

Defined Under Namespace

Modules: Progress

Constant Summary collapse

Error = 
Class.new(RuntimeError)
VERSION = 
'0.7.0'.freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Progress

#on_progress, #progress

Constructor Details

#initialize ⇒ Promise

Returns a new instance of Promise.



25
26
27
28
 
# File 'lib/promise.rb', line 25

def initialize
  @state = :pending
  @callbacks = []
end

Instance Attribute Details

#reason ⇒ Object (readonly)

Returns the value of attribute reason.



14
15
16
 
# File 'lib/promise.rb', line 14

def reason
  @reason
end

#state ⇒ Object (readonly)

Returns the value of attribute state.



14
15
16
 
# File 'lib/promise.rb', line 14

def state
  @state
end

#value ⇒ Object (readonly)

Returns the value of attribute value.



14
15
16
 
# File 'lib/promise.rb', line 14

def value
  @value
end

Class Method Details

.all(enumerable) ⇒ Object 



21
22
23
 
# File 'lib/promise.rb', line 21

def self.all(enumerable)
  Group.new(new, enumerable).promise
end

.resolve(obj) ⇒ Object 



16
17
18
19
 
# File 'lib/promise.rb', line 16

def self.resolve(obj)
  return obj if obj.is_a?(self)
  new.tap { |promise| promise.fulfill(obj) }
end

Instance Method Details

#defer ⇒ Object 



80
81
82
 
# File 'lib/promise.rb', line 80

def defer
  yield
end

#fulfill(value = nil) ⇒ Object 



61
62
63
64
65
66
67
68
69
70
71
 
# File 'lib/promise.rb', line 61

def fulfill(value = nil)
  if Promise === value
    Callback.assume_state(value, self)
  else
    dispatch do
      @state = :fulfilled
      @value = value
    end
  end
  nil
end

#fulfilled? ⇒ Boolean

Returns:

  • (Boolean) 


34
35
36
 
# File 'lib/promise.rb', line 34

def fulfilled?
  state.equal?(:fulfilled)
end

#pending? ⇒ Boolean

Returns:

  • (Boolean) 


30
31
32
 
# File 'lib/promise.rb', line 30

def pending?
  state.equal?(:pending)
end

#reject(reason = nil) ⇒ Object 



73
74
75
76
77
78
 
# File 'lib/promise.rb', line 73

def reject(reason = nil)
  dispatch do
    @state = :rejected
    @reason = reason_coercion(reason || Error)
  end
end

#rejected? ⇒ Boolean

Returns:

  • (Boolean) 


38
39
40
 
# File 'lib/promise.rb', line 38

def rejected?
  state.equal?(:rejected)
end

#rescue(&block) ⇒ Object Also known as: catch 



50
51
52
 
# File 'lib/promise.rb', line 50

def rescue(&block)
  self.then(nil, block)
end

#sync ⇒ Object 



55
56
57
58
59
 
# File 'lib/promise.rb', line 55

def sync
  wait if pending?
  raise reason if rejected?
  value
end

#then(on_fulfill = nil, on_reject = nil, &block) ⇒ Object 



42
43
44
45
46
47
48
 
# File 'lib/promise.rb', line 42

def then(on_fulfill = nil, on_reject = nil, &block)
  on_fulfill ||= block
  next_promise = self.class.new

  add_callback(Callback.new(self, on_fulfill, on_reject, next_promise))
  next_promise
end