7. Events ¶

Table of Contents

7.1. Introduction ¶

DStore makes the use of an Event Manager in the Store and Models themselves.

These events allow you to hook custom code before or after an action takes place.

In fact, this is exactly how DStore-ACL works to provide a security layer to DStore Models.

7.1.1. Listening To Events ¶

Listening to an event is as easy as adding your method to the event in question.

For example, to listen to before_init_app on the store:

from dstore import MemoryStore

def before_init_app( event, store ):
    print( "Before init store %s" % store.name )

def after_init_app( event, store ):
    print( "After init store %s" % store.name )

store = MemoryStore()
store.events.before_init_app += before_init_app
store.events.after_init_app  += after_init_app

store.init_app()

7.2. Store Events ¶

To listen to a store event, you add your method to the store’s event object.

store.events.before_init_app += method_to_call

7.2.1. init_app ¶

This event is fired before and after you execute store.init_app()

before_init_app(event, store)¶

after_init_app(event, store)¶

store¶: The Data Store that init_app is being run on

7.2.2. destroy_app ¶

This event is fired before and after you execute destroy_app on a store

before_destroy_app(event, store)¶

after_destroy_app(event, store)¶

store: The Data Store that destroy_app is being run on

7.2.3. register_models ¶

This event is fired before and after all models have been registered.

This happens automatically when init_app is run on the store

before_register_models(event, store)¶

after_register_models(event, store)¶

store: The Data Store that register_models is being run on

7.2.4. register_model ¶

This event is fired when a single Model is being registered on the store.

before_register_models(event, store, model)

after_register_models(event, store, model)

store: The Data Store that register_models is being run on

model¶: The Model Class that is being registered

7.2.5. create_all ¶

This event is fired before and after you execute create_all on a store

before_create_all(event, store)¶

after_create_all(event, store)¶

store: The Data Store that create_all is being run on

7.2.6. destroy_all ¶

This event is fired before and after you execute destroy_all on a store

before_destroy_all(event, store)¶

after_destroy_all(event, store)¶

store: The Data Store that destroy_all is being run on

7.2.7. empty_all ¶

This event is fired before and after you execute empty_all on a store

before_empty_all(event, store)¶

after_empty_all(event, store)¶

store: The Data Store that empty_all is being run on

7.2.8. connect ¶

This event is fired before and after you execute connect on a store

before_connect(event, store)¶

after_connect(event, store)¶

store: The Data Store that connect is being run on

7.2.9. disconnect ¶

This event is fired before and after you execute disconnect on a store

before_disconnect(event, store)¶

after_disconnect(event, store)¶

store: The Data Store that disconnect is being run on

7.2.10. add_bulk ¶

This event is fired before and after you execute add_bulk on a store

before_add_bulk(event, store, data)¶

after_add_bulk(event, store, data, instances)¶

store: The Data Store that disconnect is being run on

data¶: The dictionary provided that is used to add Model instances to the Store

instances¶: The Model instances that were added to the Store

7.3. Model Events ¶

To listen to a store event, you add your method to the store’s event object.

from dstore import MemoryStore, Model, var, mod

class Car( Model ):
    _namespace = "cars.make"
    _vars = [
        var.RowID,
        var.String( "manufacturer", 32, mods = [ mod.NotNull() ] ),
        var.String( "make", 32, mods = [ mod.NotNull() ] ),
        var.Number( "year", mods = [ mod.NotNull(), mod.Min( 1950 ), mod.Max( 2017 ) ] ),
    ]

def car_before_add( event, model, instance ):
    print( "Attempting to add a new %s instance" % model._namespace )

Car.events.before_add += car_before_add

7.3.1. add ¶

This event is fired before and after you attempt to add a new Model Instance

before_add(event, model, instance)¶

after_add(event, model, instance)¶

model: The Model Class that a new instance is being added to

instance¶: The instance that is attempting to be added to the Model Class storage

7.3.2. delete ¶

This event is fired before and after you attempt to delete an existing Model Instance

before_delete(event, model, instance)¶

after_delete(event, model, instance)¶

model: The Model Class of the instance to be deleted

instance: The instance that is attempting to be deleted from the Model Class storage

7.3.3. update ¶

This event is fired before and after you attempt to update an existing Model Instance

before_update(event, model, instance)¶

after_update(event, model, instance)¶

model: The Model Class of the instance to be updated

instance: The instance that is attempting to be updated

7.3.4. validate ¶

This event is fired before and after you attempt to add or update a Model Instance (i.e. on validation)

before_validate(event, model, instance)¶

after_validate(event, model, instance)¶

model: The Model Class of the instance to be added or updated

instance: The instance that is attempting to be added or updated

7.3.5. all ¶

This event is fired before and after you attempt to get all Model instances

before_all(event, model)¶

model: The Model Class of the instance to be added or updated

after_all(event, model, instances)¶

model: The Model Class of the instance to be added or updated

instances: The list of all instances

7.3.6. get ¶

This event is fired before and after you attempt to get a Model instance

before_get(event, model, row_id)¶

model: The Model Class of the instance to be added or updated

row_id¶: The ID of the instance to retrieve

after_get(event, model, instance)¶

model: The Model Class of the instance to be added or updated

instance: The Model instance retrieved

7.3.7. empty ¶

This event is fired before and after you attempt to delete all Model instances

before_empty(event, model)¶

after_empty(event, model)¶

model: The Model Class that is to be emptied

7.3.8. create ¶

This event is fired before and after you attempt to create the storage for the Model instances

before_create(event, model)¶

after_create(event, model)¶

model: The Model Class that storage is to be created for

7.3.9. destroy ¶

This event is fired before and after you attempt to destroy the storage for the Model instances

before_destroy(event, model)¶

after_destroy(event, model)¶

model: The Model Class that storage is to be destroyed for

7.3.10. filter ¶

This event is fired before and after you attempt to get a filtered list of the Model instances

before_filter(event, model, params)¶

model: The Model Class to filter for instances

params¶: A dictionary of the parameters used to filter the list

after_filter(event, model, instances, params)¶

model: The Model Class to filter for instances

instances: The filtered list of Model instances

params: A dictionary of the parameters used to filter the list