Models

Introduction

thunderdome defines two base classes for getting started with your modeling Vertex and Edge. You can use these to define entities, their properties, and the relationships between them.

Working with Vertices and Edges

class Person(thunderdome.Vertex):
    # All gremlin paths are relative to the path of the file where the class
    # is defined.
    gremlin_path = 'enrollments.groovy'

    # vid is added automatically
    name          = thunderdome.Text()
    age           = thunderdome.Integer()
    date_of_birth = thunderdome.DateTime()

    # Gremlin methods
    all_students  = thunderdome.GremlinMethod()


class Class(thunderdome.Vertex):
    name          = thunderdome.Text()
    credits       = thunderdome.Decimal()

# edges
class EnrolledIn(thunderdome.Edge):
    date_enrolled = thunderdome.DateTime()

class Teaches(thunderdome.Edge):
    overall_mood = thunderdome.Text(default='Grumpy')

Creating new Vertices

prof = Person.create(name='Professor Professorson',
                     age=300,
                     date_of_birth=datetime.datetime(1, 1, 1982))
student = Person.create(name='Johnny Boy',
                        age=56,
                        date_of_birth=datetime.datetime(1, 1, 1990))

Examine properties of the Vertex

# Print UUID for object
print prof.vid
# Print Titan-specific id for object
print prof.eid

Let's create a few more Vertices

physics = Class.create(name='Physics 264', credits=6426.3)
beekeeping = Class.create(name='Beekeeping', credits=23.3)

Now we can create Edges between our vertices

# Enroll student in both classes
EnrolledIn.create(student, physics, date_enrolled=datetime.datetime.now())
EnrolledIn.create(student, beekeeping, date_enrolled=datetime.datetime.now())

# Set professor as teacher of both classes
Teaches.create(prof, physics, overall_mood='Pedantic')
Teaches.create(prof, beekeeping, overall_mood='Itchy')

We can perform graph traversals like so:

# Get all teachers of a given class
physics.inV(Teaches)

# Get all students for a given class
physics.inV(EnrolledIn)

# Get all classes for a given student
student.outV(EnrolledIn)

# Get all moods for a list of teachers
class_moods = [x.overall_mood for x in prof.outE(Teaches)]

# Execute Gremlin method
# The eid is passed in automatically by thunderdome
all_students = prof.all_students()
for x in all_students:
    print x.name