== ontoMDE-core stand-alone usage

basic usage of ontoMDE implies the following steps:
* create or use an existing ontology (a RDF model)
* create methods an ruby classes to do whatever you want (generate Java/C++ code, transform your model, whatever).
* load the ontology model into Ruby
* load an ontology instance (data) into ruby
 

== RDFS class loading 
When invoking loadMetaModelFromFile, ontoMDE does the following things:
* Create a class for every RDFS class prefixed by C 
  (ex: RDFS class with uri uml:DataType produces a ruby class Cuml_DataType)
* Create a module for every RDFS class prefixed by M
  (ex: RDFS class with uri uml:DataType produces a ruby module Muml_DataType)
* Map RDFS generalization into module imports
  (ex: ruby class Cuml_DataType includes module Muml_DataType and Muml_NamedElement because RDFS class with uri uml:DataType inherits from uml:NamedElement)
* Creates Ruby property in module class for every RDF property
  (ex: Muml_NamedElement has a uml_name property)

Note:examples are taken from UML MetaModel included in ontomde-uml library

== Property accessors
ontoMDE offers several accessor methods for accessing a property. Accessors name derive from property name. If a property name is for example, uml_name, accessors will be uml_name, uml_name_one, uml_name_one0, ...  

=== <prop>
 returns a list of elements.
 example: uml_name, uml_ownedElement

=== <prop>_one
 returns  <prop> first element.
 Fails if <prop> list does not contain exactly one element.
 example: uml_name_one

=== <prop>_one0
 returns <prop> first element or nil if <prop> list is empty
 Fails if uml_name list contains more than one element.
 example: uml_name_one0

=== <prop>?
 returns true or false
 Because RDF stores string literal "true" or "false" this method must be used instead of <prop>_one if a boolean value is expected. 
 example: uml_isOrdered? , uml_isAbstract?

=== <prop>_inv
 returns elements 
 important note: <prop>_inv is *not* ordered. 
 example: uml_ownedElement_inv?

=== <prop>_inv_one
 returns first and only element in <prop>_inv.
 Throws an exception if <prop>_inv does not contain exactly one element.
 example:

=== <prop>_inv_one0
 returns first and only element in <prop>_inv, null if empty.
 Throws an exception if <prop>_inv contains more than one element.
 example:


==Code generator facilities

 ontoMDE-core provides facilities for writing into a file without carrying around file descriptors. A write method is defined on every ontoMDE-core model object that can be used anywhere in code, as long as it is called from inside a writeSession.

 mtk_writeSession("yourFileName.java") {
	write("Package\n)
	(...)
 }

 File generated by ontoMDE-core are in fact separated into blocks. Certain blocks can be preserved on subsequent generation. This is usefull if a file is meant to be customized, by for example, providing an implementation for a java method.

 Generated code will be in a protected block if it is inside a mtk_protected clause. 

 mtk_writeSession("yourFileName.java") {
	write("Package\n)
	(...)
	mtk_protected {
		write ("this is inside protected zone")
	}
	write ("this is *not* inside protected zone")
 }





==Context handling facilities