Class: Simple::Service::Context

Inherits:
Object
  • Object
show all
Defined in:
lib/simple/service/context.rb

Overview

A context object

Each service executes with a current context. The system manages a stack of contexts; whenever a service execution is done the current context is reverted to its previous value.

A context object can store a large number of values; the only way to set or access a value is via getters and setters. These are implemented via method_missing(..).

Also, once a value is set in the context it is not possible to change or unset it.

Instance Method Summary collapse

Constructor Details

#initialize(hsh = nil) ⇒ Context

Returns a new instance of Context.



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# File 'lib/simple/service/context.rb', line 35

def initialize(hsh = nil) # @private
  @hsh = hsh || {}
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(sym, *args, &block) ⇒ Object (private)

Raises:



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# File 'lib/simple/service/context.rb', line 59

def method_missing(sym, *args, &block)
  raise ArgumentError, "Block given" if block

  if args.count == 0 && sym =~ IDENTIFIER_REGEXP
    self[sym]
  elsif args.count == 1 && sym =~ ASSIGNMENT_REGEXP
    self[$1.to_sym] = args.first
  else
    super
  end
end

Instance Method Details

#merge(overlay) ⇒ Object

returns a new Context object, which merges the values in the overlay argument (which must be a Hash or nil) with the values in this context.

The overlay is allowed to change values in the current context.

It does not change this context.



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# File 'lib/simple/service/context.rb', line 45

def merge(overlay)
  expect! overlay => [Hash, nil]

  overlay ||= {}
  new_context_hsh = @hsh.merge(overlay)
  ::Simple::Service::Context.new(new_context_hsh)
end