Class: Levels::Configuration

Inherits:
Object
  • Object
show all
Includes:
MethodMissing
Defined in:
lib/levels/configuration.rb

Overview

A Configuration is the merging of one or more levels. This is the top level object that you will interact with most.

Examples

# In this example we'll represent a Level as a Hash.
level1 = { group1: { key1: 1 } }
level2 = { group1: { key1: 2, key2: 2 }, group2: { x: 9 } }

# The configuration exposes each group that exists in a Level.
config = Levels::Configuration.new([level1, level2])

# A Group may be accessed via hash syntax.
config[:group1] # => { key1: 2, key2: 2 }
# Or method syntax.
config.group1 # => { key1: 2, key2: 2 }

# You can check if a Group exists.
config.defined?(:group1) # => true
config.group1? # => true

Instance Method Summary collapse

Methods included from MethodMissing

#method_missing

Constructor Details

#initialize(levels, event_handler = nil) ⇒ Configuration

Internal: Initialze a new configuration.

levels - Array of Levels::Level.



30
31
32
33
34
 
# File 'lib/levels/configuration.rb', line 30

def initialize(levels, event_handler = nil)
  @levels = levels
  @event_handler = event_handler || NullEventHandler.new
  @root_observer = Levels::Audit.start(LazyEvaluator.new(self))
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class Levels::MethodMissing

Instance Method Details

#[](group_key) ⇒ Object

Public: Retrieve a group. The resulting group is the union of the named group from each Level that defines that group.

group_key - Symbol name of the group.

Examples

# In this example we'll represent a Level as a Hash.
level1 = { group: { key1: 1 } }
level2 = { group: { key1: 2, key2: 2 } }

config = Levels::Configuration.new([level1, level2])
config[:group] # => { key1: 2, key2: 2 }

Returns a Levels::ConfiguredGroup. Raises Levels::UnknownGroup if the group is not defined.

Raises:



63
64
65
66
67
 
# File 'lib/levels/configuration.rb', line 63

def [](group_key)
  raise UnknownGroup unless self.defined?(group_key)
  group_observer = @root_observer.observe_group(@event_handler)
  Levels::ConfiguredGroup.new(@levels, group_key, group_observer)
end

#defined?(group_key) ⇒ Boolean

Public: Determine if a group is defined. A group is defined if it exists in any Level.

group_key - Symbol name of the group.

Returns a Boolean.

Returns:

  • (Boolean) 


75
76
77
 
# File 'lib/levels/configuration.rb', line 75

def defined?(group_key)
  @levels.any? { |level| level.defined?(group_key) }
end

#event_handler=(event_handler) ⇒ Object

Public: Set the event handler. The event handler is notified whenever a key is read; allowing you to track exactly what is and isn’t used at runtime.

event_handler - Levels::EventHandler.

Returns nothing.



43
44
45
 
# File 'lib/levels/configuration.rb', line 43

def event_handler=(event_handler)
  @event_handler = event_handler
end

#to_enum ⇒ Object

Returns an Enumerator which yields [gruop_name, Group#to_enum].



84
85
86
87
88
89
90
91
92
93
94
95
96
 
# File 'lib/levels/configuration.rb', line 84

def to_enum
  Enumerator.new do |y|
    group_keys = Set.new
    @levels.each do |level|
      level.to_enum.each do |name, group|
        group_keys << name
      end
    end
    group_keys.each do |name|
      y << [name, self[name].to_enum]
    end
  end
end

#to_s ⇒ Object 



79
80
81
 
# File 'lib/levels/configuration.rb', line 79

def to_s
  "<Levels::Configuration #{@levels.map { |l| l._level_name }.join(', ')}>"
end