GTFS Django Models¶

The GTFS Schedule models for Django are based on the official reference of files and fields inside a feed. In gtfs-django they are provided as abstract models that must be instantiated in your Django project to be used. This design allows for flexibility and customization while adhering to the GTFS specifications.

Models are defined, for example, as:

from django.db import models


class BaseAgency(models.Model):
    """Transit agencies with service represented in this dataset."""

    agency_id = models.CharField(max_length=255, blank=True)
    agency_name = models.CharField(max_length=255)
    agency_url = models.URLField()
    agency_timezone = models.CharField(max_length=255)
    agency_lang = models.CharField(max_length=2, blank=True)
    agency_phone = models.CharField(max_length=127, blank=True, null=True)
    agency_fare_url = models.URLField(blank=True, null=True)
    agency_email = models.EmailField(max_length=254, blank=True, null=True)

    class Meta:
        abstract = True

Then, in a different Django app, you can create a concrete model that inherits from BaseAgency:

from django.db import models
from gtfs_django.models import BaseAgency

class Agency(BaseAgency):
    pass

This provides flexibility for creating auxiliary tables, adding custom fields, or overriding methods without modifying the original GTFS models. For example, to link each agency to a specific GTFS feed, you could add a foreign key to a Feed model in your concrete Agency model:

from django.db import models
from gtfs_django.models import BaseAgency


class Feed(models.Model):
    name = models.CharField(max_length=255)
    # Other fields related to the feed


class Agency(BaseAgency):
    feed = models.ForeignKey(Feed, on_delete=models.CASCADE)

This is important when different versions of GTFS feeds for the same transit system are being stored, because otherwise the unique IDs of the GTFS entities (like agency_id, route_id, etc.) could conflict across feeds.

Even more, the foreign key from one model to another should be added as well. For example, for Route:

class Route(BaseRoute):
    feed = models.ForeignKey(Feed, on_delete=models.CASCADE)
    linked_agency = models.ForeignKey(Agency, on_delete=models.CASCADE)

The suggestion of using linked_agency is made to avoid clashing in the database with agency_id.