Class: Utopia::Controller::Variables

Inherits:
Object
  • Object
show all
Defined in:
lib/utopia/controller/variables.rb

Overview

Provides a stack-based instance variable lookup mechanism. It can flatten a stack of controllers into a single hash.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Variables

Returns a new instance of Variables.



10
11
12
 
# File 'lib/utopia/controller/variables.rb', line 10

def initialize
	@controllers = []
end

Instance Method Details

#<<(controller) ⇒ Object 



18
19
20
21
22
23
24
25
26
27
 
# File 'lib/utopia/controller/variables.rb', line 18

def << controller
	if top = self.top
		# This ensures that most variables will be at the top and controllers can naturally interactive with instance variables:
		controller.copy_instance_variables(top)
	end
	
	@controllers << controller
	
	return self
end

#[](key) ⇒ Object 



60
61
62
 
# File 'lib/utopia/controller/variables.rb', line 60

def [] key
	fetch("@#{key}".to_sym, nil)
end

#fetch(key, default = self) ⇒ Object

We use self as a seninel



30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
 
# File 'lib/utopia/controller/variables.rb', line 30

def fetch(key, default=self)
	if controller = self.top
		if controller.instance_variables.include?(key)
			return controller.instance_variable_get(key)
		end
	end
	
	if block_given?
		yield(key)
	elsif !default.equal?(self)
		return default
	else
		raise KeyError.new(key)
	end
end

#to_hash ⇒ Object 



46
47
48
49
50
51
52
53
54
55
56
57
58
 
# File 'lib/utopia/controller/variables.rb', line 46

def to_hash
	attributes = {}
	
	if controller = self.top
		controller.instance_variables.each do |name|
			key = name[1..-1].to_sym
			
			attributes[key] = controller.instance_variable_get(name)
		end
	end
	
	return attributes
end

#top ⇒ Object 



14
15
16
 
# File 'lib/utopia/controller/variables.rb', line 14

def top
	@controllers.last
end