bikemap/tracking/models.py

from django.contrib.gis.db import models

# Create your models here.
from django.contrib.auth.models import User


class Track(models.Model):
    user = models.ForeignKey(User, blank=False)
    start = models.DateTimeField()
    name = models.CharField(max_length=1024, blank=False)
    description = models.TextField(blank=True)

    @property
    def finish(self):
        return self.segment_set.order_by("-time")[0].finish

    def __str__(self):
        return "[{user}] '{name}' from {start} to {finish}".format(
            user=self.user.username,
            name=self.name,
            start=self.start,
            finish=self.finish)


class Segment(models.Model):
    track = models.ForeignKey(Track)
    time = models.DateTimeField()
    number = models.IntegerField(default=1)

    @property
    def finish(self):
        return self.point_set.order_by("-time")[0].time

    def __str__(self):
        return "'{name}' Segment #{number} at {tme}".format(
            name=self.track.name,
            number=self.number,
            tme=self.time)


class Point(models.Model):
    time = models.DateTimeField()
    elevation = models.DecimalField(max_digits=20, decimal_places=2)
    segment = models.ForeignKey(Segment)

    # GeoDjango-specific: a geometry field (MultiPolygonField), and
    # overriding the default manager with a GeoManager instance.
    point = models.PointField()
    objects = models.GeoManager()

    def __str__(self):
        return "'{name}' ({lat},{lon}) -> {alt} on {time}".format(
            lat=self.point.x,
            lon=self.point.y,
            alt=self.elevation,
            time=self.time,
            name=self.segment.track.name)