peer saves v1 verbose

models.py

# -*- coding: utf-8 -*-

from django.db import models

class C(models.Model):
    role = models.CharField(max_length=20)
    an_int = models.IntegerField(default=0)
    master = models.ForeignKey('C', null=True, blank=True)

    def __unicode__(self):
        return "<C: pk=%s role=%s an_int=%s>" % (self.pk, self.role, self.an_int)
        
    def save(self, *args, **kwargs):
        # print "C.save: pk=%s role=%s master=%s an_int=%s>" % (self.pk, self.role, self.master, self.an_int)

        # print "  C.save: pk=%s role=%s an_int=%s>: calling super" % (self.pk, self.role, self.an_int)
        super(C, self).save(*args, **kwargs)
        # print "  C.save: pk=%s role=%s an_int=%s>: back from super" % (self.pk, self.role, self.an_int)

        # Find slaves if we're a saved master
        if self.pk and self.master is None:
            # print "we're a master, look for slaves and mod and save them"
            for slave in C.objects.filter(master=self):
                # print "slave=", slave
                # Does the slave differ from us?
                if self.an_int != slave.an_int:
                    slave.an_int = self.an_int
                    slave.save()
                    assert slave.an_int == self.an_int
                # else:
                #     print "slave not set"
            # else:
            #     print "no slaves"
        # else:
        #     print "no slaves"

tests.py

from django.test import TestCase

from .models import C

class C_Test(TestCase): 
    def setUp(self):
        # print "> in setUp"
        sole = C(role="sole", an_int=10)
        sole.save()
        
        master = C(role="master", an_int=11)
        master.save()
        
        slave = C(role="slave", an_int=11)
        slave.master = master
        slave.save()

        # print "> finished setUp"

    """
    def test_set_up_correctly(self):
        self.assertEquals(C.objects.get(role="sole").an_int, 10)
        self.assertEquals(C.objects.get(role="master").an_int, 11)
        self.assertEquals(C.objects.get(role="slave").an_int, 11)
    """

    """
    def test_slave_change_ignores_master(self):
        # Change an_int in the slave.
        # Verify it doesn't change in the master
        
        print "> in test_slave_change_ignores_master"

        master = C.objects.get(role="master")
        slave = C.objects.get(role="slave")
        
        slave.an_int = 12
        slave.save()
        
        self.assertEquals(master.an_int, 11)
        self.assertEquals(slave.an_int, 12)

        # How about if we reload them from the DB?
        master = C.objects.get(role="master")
        slave = C.objects.get(role="slave")
        
        self.assertEquals(master.an_int, 11)
        self.assertEquals(slave.an_int, 12)

        print "> finished test_slave_change_ignores_master"
    """

    def test_master_change_sets_slave(self):
        # Change an_int in the master.
        # Verify it also changes in the slave

        # print "> in test_master_change_sets_slave"

        master = C.objects.get(role="master")
        slave = C.objects.get(role="slave")
        
        master.an_int = 12
        master.save()
        
        self.assertEquals(master.an_int, 12)
        self.assertEquals(slave.an_int, 12)

        # How about if we reload them from the DB?
        master = C.objects.get(role="master")
        slave = C.objects.get(role="slave")
        
        self.assertEquals(master.an_int, 12)
        self.assertEquals(slave.an_int, 12)

        # print "> finished test_master_change_sets_slave"