"""
megrok.traject usage exaple.

A non-Grok model can be traversed
using megrok.traject

Dramatis personae:

- the traject root: TrajectCave
- the foreign data model: SomeForeignModel
- the Traject: TrajectForSomeForeignModel

Please see tests in app.txt.
"""

import grok
from megrok import traject


class TrajectCave(grok.Application, grok.Container):
    """
    A root application.

    Foreign models can be traversed using 
    instances of this class as a starting point.
    """

class Index(grok.View):
    """
    The default view for TrajectCave.
    """
    grok.context(TrajectCave)
    grok.name('index')
    grok.template('index')


class SomeForeignModel(object):
    """
    Some model, possibly imported.

    This class is implemented in this module
    for simplicity, but it could be any
    class imported from some non-Grok
    package.
    """

    def __init__(self,
                 name = 'noname',
                 ):
        """
        Initialises the nameof an instance.
        """
        self.size = size


class TrajectForSomeForeignModel(traject.Traject):
     """
     A traject for SomeForeignModel.
     """
     grok.context(TrajectCave)

     pattern = 'foreigners/:name'
     model = SomeForeignModel

     def factory(name='somename'):
         """
         The factory is the just the class constructor.
         """
         return SomeForeignModel(name=name)

     def arguments(some_foreign_model):
         """
         Defines only 'name' as an argument.
         """
         return dict(name=some_foreign_model.name)