Class: Gloo::Objs::Alias

Inherits:
Core::Obj show all
Defined in:
lib/gloo/objs/basic/alias.rb

Constant Summary collapse

KEYWORD = 
'alias'.freeze
KEYWORD_SHORT = 
'ln'.freeze
ALIAS_REFERENCE = 
'*'.freeze

Constants inherited from Core::Baseo

Core::Baseo::NOT_IMPLEMENTED_ERR

Instance Attribute Summary

Attributes inherited from Core::Obj

#children, #parent, #value

Attributes inherited from Core::Baseo

#name

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Core::Obj

#add_child, #add_children_on_create?, #add_default_children, can_create?, #can_receive_message?, #child_count, #child_index, #contains_child?, #delete_children, #dispatch, #display_value, #find_add_child, #find_child, #find_child_resolve_alias, #find_child_value, help, inherited, #initialize, #is_alias?, #is_container?, #is_function?, #msg_blank?, #msg_contains?, #msg_reload, #msg_responds_to?, #msg_unload, #multiline_value?, #pn, #remove_child, #render, #root?, #send_message, #set_parent, #sql_value, #type_display, #value_display, #value_is_array?, #value_is_blank?, #value_string?

Methods inherited from Core::Baseo

#initialize, #type_display

Constructor Details

This class inherits a constructor from Gloo::Core::Obj

Class Method Details

.doc_data ⇒ Object

Get the object's documentation data.



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# File 'lib/gloo/objs/basic/alias.rb', line 83

def self.doc_data
  {
    :name => KEYWORD,
    :shortcut => KEYWORD_SHORT,
    :description => 'A pointer to another object. Normal ' \
      'path-name references will refer to the aliased object. To ' \
      'refer to the alias itself, add an * at the end of the ' \
      'path-name — needed, for example, to set the value of the ' \
      'alias. The value of the alias is merely the path-name of ' \
      'the referenced object. Well constructed aliases will ' \
      'redirect to the referenced object through any number of ' \
      'steps, and relative references will also work in an alias.',
    :messages => [
      'resolve — Check to see if the object referenced exists. Sets it to true or false.'
    ],
    :notes => 'The alias also reflects (forwards) the messages of the object it points to.',
    :examples => <<~EXAMPLES.strip
      #
      # Alias object.
      #

      a [can] :
        s [string] : a string
        i [integer] : 13
        ln [alias] : a.s

        on_load [script] :
          show a.ln
          show a.ln*
          put 'a.i' into a.ln*
          put 7 into a.ln
          show a.ln
          run a.add

        #
        # Example of creating an object using an alias.
        #
        add [script] :
          put 'x' into a.ln*
          create a.ln* as string
          put 'test' into x
          show a.ln
    EXAMPLES
  }
end

.messages ⇒ Object

Get a list of message names that this object receives.



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# File 'lib/gloo/objs/basic/alias.rb', line 43

def self.messages
  return super + %w[resolve]
end

.resolve_alias(engine, obj, ref_name = nil) ⇒ Object

Is the object an alias If so, then resolve it. The ref_name is the name used to refer to the object. If it ends with the * then we won't resolve the alias since we are trying to refer to the alias itself.



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# File 'lib/gloo/objs/basic/alias.rb', line 67

def self.resolve_alias( engine, obj, ref_name = nil )
  return nil unless obj
  return obj unless obj.type_display == Gloo::Objs::Alias.typename
  return obj if ref_name&.end_with?( ALIAS_REFERENCE )

  ln = Gloo::Core::Pn.new( engine, obj.value )
  return ln.resolve
end

.short_typename ⇒ Object

The short name of the object type.



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# File 'lib/gloo/objs/basic/alias.rb', line 25

def self.short_typename
  return KEYWORD_SHORT
end

.typename ⇒ Object

The name of the object type.



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# File 'lib/gloo/objs/basic/alias.rb', line 18

def self.typename
  return KEYWORD
end

Instance Method Details

#msg_resolve ⇒ Object

Check to see if the referenced object exists.



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# File 'lib/gloo/objs/basic/alias.rb', line 50

def msg_resolve
  pn = Gloo::Core::Pn.new( @engine, self.value )
  s = pn.exists?
  @engine.heap.it.set_to s
  return s
end

#set_value(new_value) ⇒ Object

Set the value with any necessary type conversions.



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# File 'lib/gloo/objs/basic/alias.rb', line 32

def set_value( new_value )
  self.value = new_value.to_s
end