method

add_observer

v1_9_3_125 - Show latest stable - Class: Observable

add_observer(observer, func=:update)

public

Add observer as an observer on this object. so that it will receive notifications.

`observer`	the object that will be notified of changes.
`func`	Symbol naming the method that will be called when this Observable

has changes.

This method must return true for +observer.respond_to?+ and will
receive <tt>*arg</tt> when #notify_observers is called, where
<tt>*arg</tt> is the value passed to #notify_observers by this
Observable

# File lib/observer.rb, line 126
  def add_observer(observer, func=:update)
    @observer_peers = {} unless defined? @observer_peers
    unless observer.respond_to? func
      raise NoMethodError, "observer does not respond to `#{func.to_s}'"
    end
    @observer_peers[observer] = func
  end

add_observer

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