class Jogger

Allows to formulate traversals by using predefined named traversals. Also allows for method chaining.

All named traversals are defined in {Jogger::NamedTraversals}, so that’s where you should define your own.

Instances have a @current_traversal variable that is updated with each call. Beware: Jogger uses method missing to delegate unknown methods to the current traversal. So after you’re done chaining things, you can do more stuff with it, e.g. call count on it:

t = Jogger.new(some_node)
t.go.some.where.count

Everything except for {Jogger#result} is called on the ‘@current_traversal`, so what you really want to do to get the count of your traversal would be

t = Jogger.new(some_node)
t.go.some.where.result.count

Public Class Methods

new(initial_node = nil) click to toggle source

@param initial_node [Object] A node to start out with. Can also be

the result of a prior traversal you did outside of this class

# File lib/jogger.rb, line 30
def initialize(initial_node = nil)
  @current_traversal = initial_node
end

traverse(traversal_base, named_traversal, opts = nil) click to toggle source

Runs a named traversal on a given traversal. For example, you could give it a start node as traversal base and a traversal named :go_to_all_subscribers to go to all subscribers from that node.

@param traversal_base [Object] The result of a previous traversal

or a pacer node you want to begin your traversal with

@param named_traversal [Symbol] The name of the predefined traversal

you want to run on the traversal_base

@param opts [Object] Whatever you want to pass to the named traverser @return [Object] The result of the traversal.

# File lib/jogger.rb, line 73
def self.traverse(traversal_base, named_traversal, opts = nil)
  raise UnknownTraversalError, "Unknown traversal #{named_traversal}" unless valid_traversal?(named_traversal)
  args = [named_traversal, traversal_base] + [*opts].compact
  Jogger::NamedTraversals.send(*args)
end

Private Class Methods

valid_traversal?(traversal) click to toggle source

# File lib/jogger.rb, line 81
def self.valid_traversal?(traversal)
  Jogger::NamedTraversals.respond_to? traversal
end

Public Instance Methods

method_missing(method, *args, &block) click to toggle source

Runs the traversal with the same name as the called method on the current traversal and replaces the current traversal (== the state) with the results of the named traversal.

If you call a method that is not a named traversal, the method call is delegated to the @current traversal. Still, this will return self. This is useful for more traversals after named routes.

@return [Jogger] Returns itself so you can chain multiple

calls just like you would do with pacer

# File lib/jogger.rb, line 49
def method_missing(method, *args, &block)
  begin
    traversal_args = [method, args].flatten.compact
    @current_traversal = Jogger.traverse(@current_traversal, method, args)
  rescue UnknownTraversalError => a
    begin
      @current_traversal = @current_traversal.send(method, *args, &block)
    rescue NoMethodError => m
      raise "Unknown traversal #{method}. From (#{a}) via (#{m}) (method_missing rocks)"
    end
  end
  self
end

result() click to toggle source

@return [Hash] The current state of the traversal as returned by pacer

# File lib/jogger.rb, line 35
def result
  @current_traversal
end