UPGRADING.txt

2 September 2011:

This revision contains a breaking change in the Occurrence and Generator models, to use start + duration, rather than start + end, and to have consistency between their APIs.

The Generator model repeat_until is now a date, rather than a datetime, for simplicity (only one occurrence per day is generated).

To migrate, using South:

1) Create a migration representing your app's current state, if you haven't already.
2) Update event tools to a current version.
3) Create a manual migration which adds the _duration fields to Occurrence and Generator (see sample code)

    def forwards(self, orm):

        # Adding field 'Occurrence.duration'
        db.add_column('events_occurrence', '_duration', self.gf('django.db.models.fields.PositiveIntegerField')(null=True, blank=True), keep_default=False)
        # Copy info over
        for o in orm['events.occurrence'].objects.all():
            if o.end and o.end != o.start:
                td = o.end - o.start
                secs = td.days * 24 * 60 * 60 + td.seconds
                o._duration = secs/60
                o.save()

        # Adding field 'Generator._duration'
        db.add_column('events_generator', '_duration', self.gf('django.db.models.fields.PositiveIntegerField')(null=True, blank=True), keep_default=False)
        # Copy info over
        for g in orm['events.generator'].objects.all():
            if g.event_end and g.event_end != g.event_start:
                td = g.event_end - g.event_start
                secs = td.days * 24 * 60 * 60 + td.seconds
                g._duration = secs/60
                g.save()

    def backwards(self, orm):

        # Deleting field 'Occurrence.duration'
        db.delete_column('events_occurrence', '_duration')

        # Deleting field 'Generator._duration'
        db.delete_column('events_generator', '_duration')


4) Create a manual migration which removes the *end fields

    def forwards(self, orm):

        # Deleting field 'Occurrence.end'
        db.delete_column('events_occurrence', 'end')

        # Deleting field 'Generator.event_end'
        db.delete_column('events_generator', 'event_end')

    def backwards(self, orm):

        # Adding field 'Occurrence.end'
        db.add_column('events_occurrence', 'end', self.gf('django.db.models.fields.DateTimeField')(default='', blank=True, db_index=True), keep_default=False)

        for o in orm['events.occurrence'].objects.all():
            if o._duration:
                o.end = o.start + datetime.timedelta(seconds = o._duration * 60)
            else:
                o.end = o.start
            o.save()

        # Adding field 'Generator.event_end'
        db.add_column('events_generator', 'event_end', self.gf('django.db.models.fields.DateTimeField')(default='', blank=True, db_index=True), keep_default=False)

        for o in orm['events.generator'].objects.all():
            if o._duration:
                o.event_end = o.event_start + datetime.timedelta(seconds = o._duration * 60)
            else:
                o.event_end = o.event_start
            o.save()


5) Create a manual migration which renames event_start to start in Generator

    def forwards(self, orm):

        # Renaming field 'Generator.event_start'
        db.rename_column('events_generator', 'event_start', 'start')

    def backwards(self, orm):

        # Renaming field 'Generator.start'
        db.rename_column('events_generator', 'start', 'event_start')


6) Create a manual migration which adds repeat_until_date to Generator, and populates the values

    def forwards(self, orm):

        # Adding field 'Generator.repeat_until_date'
        db.add_column('events_generator', 'repeat_until_date', self.gf('django.db.models.fields.DateField')(null=True, blank=True), keep_default=False)

        for o in orm['events.generator'].objects.all():
            if o.repeat_until:
                o.repeat_until_date = o.repeat_until.date()
                o.save()

    def backwards(self, orm):

        # Deleting field 'Generator.repeat_until_date'
        db.delete_column('events_generator', 'repeat_until_date')


7) Create a manual migration which removes repeat_until (the datetime), and renames repeat_until_date to repeat_until.

    def forwards(self, orm):

        # Deleting field 'Generator.repeat_until'
        db.delete_column('events_generator', 'repeat_until')
        db.rename_column('events_generator', 'repeat_until_date', 'repeat_until')

    def backwards(self, orm):

        # Adding field 'Generator.repeat_until'
        db.rename_column('events_generator', 'repeat_until', 'repeat_until_date')
        db.add_column('events_generator', 'repeat_until', self.gf('django.db.models.fields.DateTimeField')(null=True, blank=True), keep_default=False)

        for o in orm['events.generator'].objects.all():
            if o.repeat_until_date:
                o.repeat_until = datetime.datetime.combine(o.repeat_until_date, datetime.time.max)
                o.save()


8) ./manage.py schemamigration youreventsapp --auto should pick up any other changes (fields which are now required, etc.). However, the GeneratorModel rule field is now required. In EventTools 1, Generators without a rule were 'one-off' events, which should now be stored as separate Occurrences. (If you do a migration like this, update this document with sample code!)


# === Snippet to migrate exclusions from generators ===
from dateutil import parser

class Migration(SchemaMigration):

    def forwards(self, orm):
        for generator in orm['events.generator'].objects.filter(exceptions__isnull=False):
            for exc in generator.exceptions.keys():
                dt = parser.parse(exc)
                orm['events.exclusion'].objects.create(event=generator.event, start=dt)