Django 1.7 And You

A talk I gave at the San Francisco Django Meetup group

Transcript

1. 1.7
   Andrew Godwin
   @andrewgodwin
   & you
   

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2. Andrew Godwin
   Author of South migrations library
   Hi, I'm
   Author of 1.7 Django migrations
   Generally far too involved in Django
   

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3. Django 1.7
   Migrations
   Scheduled release: May 15th
   (we'll probably miss it)
   App loading refactor
   Checks framework
   select_related filters
   Custom lookups
   

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4. Migrations
   They're pretty good.
   

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5. The (second) Plan
   Django
   Schema backend
   ORM Hooks
   South 2
   Migration handling
   User interface
   Backport for 1.4 - 1.6
   

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6. Logically Separate
   Schema backend
   ORM Hooks
   Migration handling
   User interface
   SchemaEditor Migrations
   

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7. A New Format
   More concise
   Declarative
   Introspectable
   

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8. Migration actions
   Frozen ORM
   

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10. In-memory running
    Creates models from migration sets
    Autodetector diffs created from on-disk
    Used to feed SchemaEditor / ORM
    

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11. Backwards Compatability
    Auto-applies first migration if tables exist
    Ignores South-style migrations
    South will start looking for south_migrations
    

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12. App Loading
    Mostly internal change
    App objects per-app
    Start of long path away from settings
    

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13. Checks Framework
    Proper support for project-level validation
    Old validation moved in
    Upgrade warnings now possible
    

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14. from django.core.checks import register
    @register()
    def example_check(app_configs, **kwargs):
    errors = []
    # ... your check logic here
    return errors
    

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15. prefetch_related control
    Now accepts a Prefetch object
    Can customise order, select_related, or filter
    

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16. Pizza.objects.prefetch_related(
    Prefetch(
    'restaurants',
    queryset=Restaurant.objects.select_related('best_pizza'),
    )
    )
    

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17. Custom Lookups
    Allows for more powerful Field subclasses
    You can stop using .extra() and .raw() as much
    

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18. from django.db.models import Lookup
    class NotEqual(Lookup):
    lookup_name = 'ne'
    def as_sql(self, qn, connection):
    lhs, lhs_params = self.process_lhs(qn, connection)
    rhs, rhs_params = self.process_rhs(qn, connection)
    params = lhs_params + rhs_params
    return '%s <> %s' % (lhs, rhs), params
    

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19. Important Upgrade Notes
    

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20. Fields need deconstruct()
    It's a required new method for all fields.
    

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21. syncdb is deprecated
    Use migrate (old apps will still work)
    

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22. initial_data is dead
    Use data migrations and the ORM instead
    

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23. Django 1.8?
    LTS
    Migrations for contrib apps
    PostgreSQL improvements?
    

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24. Thanks.
    @andrewgodwin
    aeracode.org
    

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