module Glimmer::DataBinding::Observer
Mixin representing Observer
trait from Observer
Design Pattern Allows classes to include without interfering with their inheritance hierarchy.
Includes a default implementation that can receive an observer block Example: Observer.proc
{|new_value| puts new_value} Subclasses may override
Constants
- Registration
Public Class Methods
Source
# File lib/glimmer/data_binding/observer.rb, line 58 def proc(&observer_block) Proc.new(&observer_block) end
Public Instance Methods
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# File lib/glimmer/data_binding/observer.rb, line 141 def add_dependent(parent_to_dependent_hash) registration = parent_to_dependent_hash.keys.first dependent = parent_to_dependent_hash.values.first dependents_for(registration) << dependent end
add dependent observer to unregister when unregistering observer
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# File lib/glimmer/data_binding/observer.rb, line 155 def call(new_value = nil, *extra_args) raise Error, 'Not implemented!' end
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# File lib/glimmer/data_binding/observer.rb, line 159 def compact_args(args) args = args[0...-1] if args.last == {} args = args[0...-1] if args.last == [] args.compact end
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# File lib/glimmer/data_binding/observer.rb, line 75 def dependents @dependents ||= Concurrent::Hash.new end
mapping of registrations to dependents {[observable, property] => [[dependent, dependent_observable, dependent_property], …]}
Source
# File lib/glimmer/data_binding/observer.rb, line 79 def dependents_for(registration) dependents[registration.object_id] ||= Concurrent::Set.new end
Alias for: unobserve_dependents_with_observable
Source
# File lib/glimmer/data_binding/observer.rb, line 85 def observe(observable, *args) options = args.last.is_a?(Hash) ? args.last : {} return if observable.nil? return if options[:ignore_frozen] && observable.frozen? unless observable.is_a?(Observable) # TODO refactor code to be more smart/polymorphic/automated and honor open/closed principle (e.g. for SomeClass, search if there is ObservableSomeClass) if observable.is_a?(Array) observable.extend(ObservableArray) elsif observable.is_a?(Hash) observable.extend(ObservableHash) else observable.extend(ObservableModel) end end args = compact_args(args) observable.add_observer(self, *args) ensure_registration_for!(observable, *args) end
registers observer in an observable on args usually containing a property and options (optional) observer maintains registration list to unregister later
Also aliased as: register
Source
# File lib/glimmer/data_binding/observer.rb, line 67 def registration_for(observable, *args) args = compact_args(args) registrations[[observable.object_id, args]] ||= Registration.new(observer: self, observable: observable, args: args) end
Also aliased as: ensure_registration_for!
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# File lib/glimmer/data_binding/observer.rb, line 63 def registrations @registrations ||= Concurrent::Hash.new end
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# File lib/glimmer/data_binding/observer.rb, line 147 def remove_dependent(parent_to_dependent_hash) registration = parent_to_dependent_hash.keys.first dependent = parent_to_dependent_hash.values.first dependents_for(registration).delete(dependent).tap do dependents.delete([registration.object_id]) if dependents_for(registration).empty? end end
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# File lib/glimmer/data_binding/observer.rb, line 105 def unobserve(observable, *args) return unless observable.is_a?(Observable) args = compact_args(args) registration = registration_for(observable, *args) registrations.delete([observable.object_id, args]) registration.tap do |registration| dependents_for(registration).each do |dependent| remove_dependent(registration => dependent) dependent.deregister if dependent != registration end observable.remove_observer(self, *args) end end
Also aliased as: unregister, deregister
Source
# File lib/glimmer/data_binding/observer.rb, line 131 def unobserve_all_observables registrations.values.dup.each do |registration| registration.deregister registrations.delete([registration.observable.object_id, registration.args]) end end
cleans up all registrations in observables
Also aliased as: unregister_all_observables, deregister_all_observables
Source
# File lib/glimmer/data_binding/observer.rb, line 121 def unobserve_dependents_with_observable(registration, dependent_observable) thedependents = dependents_for(registration).select do |thedependent| thedependent.observable == dependent_observable end thedependents.each(&:deregister) end
Also aliased as: unregister_dependents_with_observable, deregister_dependents_with_observable