| commit | author | age | ||
| b50a19 | 1 | from sqlalchemy import engine_from_config |
| SP | 2 | from sqlalchemy.orm import sessionmaker |
| 3 | from sqlalchemy.orm import configure_mappers | |
| 4 | import zope.sqlalchemy | |
| 5 | ||
| 6 | # import or define all models here to ensure they are attached to the | |
| 7 | # Base.metadata prior to any initialization routines | |
| 293942 | 8 | from .mymodel import MyModel # flake8: noqa |
| b50a19 | 9 | |
| SP | 10 | # run configure_mappers after defining all of the models to ensure |
| 11 | # all relationships can be setup | |
| 12 | configure_mappers() | |
| 13 | ||
| 14 | ||
| 15 | def get_engine(settings, prefix='sqlalchemy.'): | |
| 16 | return engine_from_config(settings, prefix) | |
| 17 | ||
| 18 | ||
| 19 | def get_session_factory(engine): | |
| 20 | factory = sessionmaker() | |
| 21 | factory.configure(bind=engine) | |
| 22 | return factory | |
| 23 | ||
| 24 | ||
| 25 | def get_tm_session(session_factory, transaction_manager): | |
| 26 | """ | |
| 27 | Get a ``sqlalchemy.orm.Session`` instance backed by a transaction. | |
| 28 | ||
| 29 | This function will hook the session to the transaction manager which | |
| 30 | will take care of committing any changes. | |
| 31 | ||
| 32 | - When using pyramid_tm it will automatically be committed or aborted | |
| 33 | depending on whether an exception is raised. | |
| 34 | ||
| 35 | - When using scripts you should wrap the session in a manager yourself. | |
| 36 | For example:: | |
| 37 | ||
| 38 | import transaction | |
| 39 | ||
| 40 | engine = get_engine(settings) | |
| 41 | session_factory = get_session_factory(engine) | |
| 42 | with transaction.manager: | |
| 43 | dbsession = get_tm_session(session_factory, transaction.manager) | |
| 44 | ||
| 45 | """ | |
| 46 | dbsession = session_factory() | |
| 47 | zope.sqlalchemy.register( | |
| 48 | dbsession, transaction_manager=transaction_manager) | |
| 49 | return dbsession | |
| 50 | ||
| 51 | ||
| 52 | def includeme(config): | |
| 53 | """ | |
| 54 | Initialize the model for a Pyramid app. | |
| 55 | ||
| 56 | Activate this setup using ``config.include('tutorial.models')``. | |
| 57 | ||
| 58 | """ | |
| 59 | settings = config.get_settings() | |
| d83888 | 60 | settings['tm.manager_hook'] = 'pyramid_tm.explicit_manager' |
| b50a19 | 61 | |
| SP | 62 | # use pyramid_tm to hook the transaction lifecycle to the request |
| 63 | config.include('pyramid_tm') | |
| 64 | ||
| 2c0e3e | 65 | # use pyramid_retry to retry a request when transient exceptions occur |
| SP | 66 | config.include('pyramid_retry') |
| 67 | ||
| b50a19 | 68 | session_factory = get_session_factory(get_engine(settings)) |
| SP | 69 | config.registry['dbsession_factory'] = session_factory |
| 70 | ||
| 71 | # make request.dbsession available for use in Pyramid | |
| 72 | config.add_request_method( | |
| 73 | # r.tm is the transaction manager used by pyramid_tm | |
| 74 | lambda r: get_tm_session(session_factory, r.tm), | |
| 75 | 'dbsession', | |
| 76 | reify=True | |
| 77 | ) | |
