Demo of loading the Geppetto metamodel and models, modication and XMI serialization using PyEcore

geppetto_pyecore_demo.py

# Ecore core and PyEcore runtime core
import pyecore.ecore as Ecore

# global_registry for metamodels registration
from pyecore.resources import global_registry

# Resource for load/save data, URI for file location model/metamodel
# ResourceSet to create a resource container and isolate the loaded metamodel
from pyecore.resources import ResourceSet, Resource, URI

# To fetch URI from an Http address
from pyecore.resources.resource import HttpURI


# Only for display purposes
def tree_display(root, level=''):
    prefix = '+-- ' if root.eContainer() else '/ '
    if hasattr(root, 'name'):
        display = '{0} [{1}]'.format(root.name, root.eClass.name)
    else:
        display = root.eClass.name
    if root.eContainmentFeature():
        display += ' {{{0}}}'.format(root.eURIFragment())
    print(level + prefix + display)
    for eobject in root.eContents:
        tree_display(eobject, level + '  ')


if __name__ == '__main__':
    # Register static Ecore metamodel
    global_registry[Ecore.nsURI] = Ecore

    # Create a new ResourceSet
    rset = ResourceSet()

    # We create the XMLType resource
    # (required regarding the way the metamodel is built)
    int_conversion = lambda x: int(x)

    String = Ecore.EDataType('String', str)

    Double = Ecore.EDataType('Double', int, 0, from_string=int_conversion)

    Int = Ecore.EDataType('Int', int, 0, from_string=int_conversion)

    IntObject = Ecore.EDataType('IntObject', int, None,
                                from_string=int_conversion)

    Boolean = Ecore.EDataType('Boolean', bool, False,
                              from_string=lambda x: x in ['True', 'true'])

    EJavaObject = Ecore.EDataType('EJavaObject', object)

    Long = Ecore.EDataType('Long', int, 0, from_string=int_conversion)

    xmltype = Ecore.EPackage()  # XMLType resource root
    xmltype.eClassifiers.extend([String,
                                 Double,
                                 Int,
                                 EJavaObject,
                                 Long,
                                 Boolean,
                                 IntObject])
    xmltype.nsURI = 'http://www.eclipse.org/emf/2003/XMLType'
    xmltype.nsPrefix = 'xmltype'
    xmltype.name = 'xmltype'

    # We register it in the ResourceSet as a metamodel
    # at the 'http://www.eclipse.org/emf/2003/XMLType' URI
    rset.metamodel_registry[xmltype.nsURI] = xmltype

    # Load the Geppetto metamodel from:
    # https://raw.githubusercontent.com/openworm/org.geppetto.model/development/src/main/resources/geppettoModel.ecore
    metamodel_url = ('https://raw.githubusercontent.com/openworm/'
                     'org.geppetto.model/development/src/main/resources/'
                     'geppettoModel.ecore')
    resource = rset.get_resource(HttpURI(metamodel_url))
    mm_root = resource.contents[0]  # At this point, mm_root is the Geppetto metamodel root

    # Register all the EPackages inside the ResourceSet
    rset.metamodel_registry[mm_root.nsURI] = mm_root
    for subpack in mm_root.eSubpackages:
        rset.metamodel_registry[subpack.nsURI] = subpack

    # Load a Geppetto test model from:
    # https://raw.githubusercontent.com/openworm/org.geppetto.model/development/src/test/resources/GeppettoModelTest.xmi
    model_url = ('https://raw.githubusercontent.com/openworm/'
                 'org.geppetto.model/development/src/test/resources/'
                 'GeppettoModelTest2.xmi')
    resource = rset.get_resource(HttpURI(model_url))
    root = resource.contents[0]

    # We display the model
    tree_display(root)

    # We add a new variable (playing with reflection stuffs)
    var1 = root.variables[0]  # We get the first variable
    Variable = var1.eClass  # We get its metaclasse
    var2 = Variable()  # We create a new instance
    var2.types.append(var1.types[0])
    var2.name = 'myvar'
    var2.id = var2.name + '_id'
    root.variables.append(var2)  # We attach the new instance to the model

    tree_display(root)

    # We save the new instance in a file resource
    resource.save(output=URI('test_demo.xmi'))