Models

Models for the dasf-broker-django app.

Models:

`BrokerMessage`(args, *kwargs)	A message sent to the broker.
`BrokerTopic`(args, *kwargs)	A topic for producing and consuming requests via websocket
`ResponseTopic`(args, *kwargs)	A topic that accepts responses for messages.

Classes:

`BrokerTopicManager`(args, *kwargs)	A manager for broker topics.
`BrokerTopicQuerySet`([model, query, using, hints])	A queryset for broker topics.

class dasf_broker.models.BrokerMessage(*args, **kwargs)

Bases: Model

A message sent to the broker.

Parameters:

id (BigAutoField) – Primary key: ID
message_id (UUIDField) – Message id. Message ID
context (IntegerField) – Context. Message context for messages from a producer.
content (JSONField) – Content. The content of the message.
date_created (DateTimeField) – Date created. The date and time when the message has been created

Relationship fields:

Parameters:

topic (ForeignKey to BrokerTopic) – Topic. The topic the message was published for. (related name: brokermessage)
user (ForeignKey to User) – User. The user who produced the message. (related name: brokermessage)
delivered_to (ManyToManyField to User) – Delivered to. To whom has this message been delivered already? (related name: brokermessage_set_delivered)

Reverse relationships:

Parameters:: responsetopic (Reverse ManyToManyField from ResponseTopic) – All response topics of this broker message (related name of source_messages)

Miscellaneous:

`DoesNotExist`
`MultipleObjectsReturned`

Model Fields:

`content`	Type: `JSONField`
`context`	Type: `IntegerField`
`date_created`	Type: `DateTimeField`
`id`	Type: `BigAutoField`
`message_id`	Type: `UUIDField`
`topic`	Type: `ForeignKey` to `BrokerTopic`
`user`	Type: `ForeignKey` to `User`

Attributes:

`delivered_to`	Type: `ManyToManyField` to `User`
`delivered_to_all`	Test if the message has been delivered to all consumers.
`is_response`	Is this message a response to a DASF request?
`objects`
`responsetopic_set`	Type: Reverse `ManyToManyField` from `ResponseTopic`
`topic_id`	Internal field, use `topic` instead.
`user_id`	Internal field, use `user` instead.

Methods:

`get_next_by_date_created`(*[, field, is_next])	Finds next instance based on `date_created`.
`get_previous_by_date_created`(*[, field, is_next])	Finds previous instance based on `date_created`.
`send`()	Send the message via the websocket.

exception DoesNotExist: Bases: ObjectDoesNotExist

exception MultipleObjectsReturned: Bases: MultipleObjectsReturned

content

Type: JSONField

Content. The content of the message.

A wrapper for a deferred-loading field. When the value is read from this

context

Type: IntegerField

Context. Message context for messages from a producer.

A wrapper for a deferred-loading field. When the value is read from this

date_created

Type: DateTimeField

Date created. The date and time when the message has been created

A wrapper for a deferred-loading field. When the value is read from this

delivered_to

Type: ManyToManyField to User

Delivered to. To whom has this message been delivered already? (related name: brokermessage_set_delivered)

Accessor to the related objects manager on the forward and reverse sides of a many-to-many relation.

In the example:

class Pizza(Model):
    toppings = ManyToManyField(Topping, related_name='pizzas')

Pizza.toppings and Topping.pizzas are ManyToManyDescriptor instances.

Most of the implementation is delegated to a dynamically defined manager

property delivered_to_all: bool: Test if the message has been delivered to all consumers.

get_next_by_date_created(*, field=<django.db.models.DateTimeField: date_created>, is_next=True, **kwargs): Finds next instance based on date_created. See get_next_by_FOO() for more information.

get_previous_by_date_created(*, field=<django.db.models.DateTimeField: date_created>, is_next=False, **kwargs): Finds previous instance based on date_created. See get_previous_by_FOO() for more information.

id

Type: BigAutoField

Primary key: ID

A wrapper for a deferred-loading field. When the value is read from this

property is_response: bool: Is this message a response to a DASF request?

message_id

Type: UUIDField

Message id. Message ID

A wrapper for a deferred-loading field. When the value is read from this

objects = <django.db.models.Manager object>

responsetopic_set

Type: Reverse ManyToManyField from ResponseTopic

All response topics of this broker message (related name of source_messages)

Accessor to the related objects manager on the forward and reverse sides of a many-to-many relation.

In the example:

class Pizza(Model):
    toppings = ManyToManyField(Topping, related_name='pizzas')

Pizza.toppings and Topping.pizzas are ManyToManyDescriptor instances.

Most of the implementation is delegated to a dynamically defined manager

send(): Send the message via the websocket.

topic

Type: ForeignKey to BrokerTopic

Topic. The topic the message was published for. (related name: brokermessage)

Accessor to the related object on the forward side of a many-to-one or one-to-one (via ForwardOneToOneDescriptor subclass) relation.

In the example:

class Child(Model):
    parent = ForeignKey(Parent, related_name='children')

topic_id: Internal field, use topic instead.

user

Type: ForeignKey to User

User. The user who produced the message. (related name: brokermessage)

Accessor to the related object on the forward side of a many-to-one or one-to-one (via ForwardOneToOneDescriptor subclass) relation.

In the example:

class Child(Model):
    parent = ForeignKey(Parent, related_name='children')

user_id: Internal field, use user instead.

class dasf_broker.models.BrokerTopic(*args, **kwargs)

Bases: Model

A topic for producing and consuming requests via websocket

Parameters:

id (BigAutoField) – Primary key: ID
slug (SlugField) – Slug. Unique identifier for the topic.
is_public (BooleanField) – Is public. Can everyone publish data to this topic?
date_created (DateTimeField) – Date created. The date and time when the message has been created
last_ping (DateTimeField) – Last ping. When has the topic last been pinged?
last_pong (DateTimeField) – Last pong. When has the topic last replyed on a ping?
supports_dasf (BooleanField) – Supports dasf. Does this topic support the DASF messaging protocoll?
store_messages (CharField) – Store messages. Should messages be stored?
garbage_collect_on (DateTimeField) – Garbage collect on. Specify a time when this topic should be removed from the database.
api_info (JSONField) –
Api info

metadata field to allow additional attributes for topics.

Reverse relationships:

Parameters:

brokermessage (Reverse ForeignKey from BrokerMessage) – All broker messages of this broker topic (related name of topic)
responsetopic (Reverse OneToOneField from ResponseTopic) – The response topic of this broker topic (related name of brokertopic_ptr)
responsetopics (Reverse ForeignKey from ResponseTopic) – All responsetopics of this broker topic (related name of is_response_for)

Miscellaneous:

`DoesNotExist`
`MultipleObjectsReturned`

Classes:

StoreMessageChoices(value)

Choices for storing messages.

Model Fields:

`api_info`	Type: `JSONField`
`date_created`	Type: `DateTimeField`
`garbage_collect_on`	Type: `DateTimeField`
`id`	Type: `BigAutoField`
`is_public`	Type: `BooleanField`
`last_ping`	Type: `DateTimeField`
`last_pong`	Type: `DateTimeField`
`slug`	Type: `SlugField`
`store_messages`	Type: `CharField`
`supports_dasf`	Type: `BooleanField`

Attributes:

`availability`	Get the online/offline status for the topic.
`brokermessage_set`	Type: Reverse `ForeignKey` from `BrokerMessage`
`consumers`
`effective_store_messages`	Get the store message rule for this topic.
`is_response_topic`	Is this topic a responsetopic?
`objects`
`producers`
`responsetopic`	Type: Reverse `OneToOneField` from `ResponseTopic`
`responsetopics`	Type: Reverse `ForeignKey` from `ResponseTopic`
`status_viewers`

Methods:

`build_websocket_url`(request[, route])
`create_and_send_message`(user, content)	Create and send a message for the user
`get_next_by_date_created`(*[, field, is_next])	Finds next instance based on `date_created`.
`get_outstanding_messages`([user])	Get the messages that still need to be send.
`get_previous_by_date_created`(*[, field, is_next])	Finds previous instance based on `date_created`.
`get_store_messages_display`(*[, field])	Shows the label of the `store_messages`.
`get_websocket_url`(request)	Get the websocket url for this topic.
`ping`()	Create a ping message and send it to the consumer.

exception DoesNotExist: Bases: ObjectDoesNotExist

exception MultipleObjectsReturned: Bases: MultipleObjectsReturned

class StoreMessageChoices(value)

Bases: TextChoices

Choices for storing messages.

Attributes:

`CACHE`
`CACHEALL`
`DISABLED`
`STORE`

CACHE = 'cache'

CACHEALL = 'cacheall'

DISABLED = 'disabled'

STORE = 'store'

api_info

Type: JSONField

Api info

availability

Get the online/offline status for the topic.

This value can be True, False or None:

None: The status is unknown. This occurs when the last ping was more than two minutes ago or the topic has never, been pinged.
False: The was no pong yet or the last pong was before the last ping and the last ping was less than two minutes ago.
True: The topic is online, i.e. we received a pong after the last ping

brokermessage_set

Type: Reverse ForeignKey from BrokerMessage

All broker messages of this broker topic (related name of topic)

Accessor to the related objects manager on the reverse side of a many-to-one relation.

In the example:

class Child(Model):
    parent = ForeignKey(Parent, related_name='children')

Parent.children is a ReverseManyToOneDescriptor instance.

Most of the implementation is delegated to a dynamically defined manager

classmethod build_websocket_url(request, route: str | None = None) → str

property consumers: models.QuerySet[User]

create_and_send_message(user: User, content: Dict): Create and send a message for the user

date_created

Type: DateTimeField

Date created. The date and time when the message has been created

A wrapper for a deferred-loading field. When the value is read from this

property effective_store_messages: StoreMessageChoices: Get the store message rule for this topic.

garbage_collect_on

Type: DateTimeField

Garbage collect on. Specify a time when this topic should be removed from the database.

A wrapper for a deferred-loading field. When the value is read from this

get_next_by_date_created(*, field=<django.db.models.DateTimeField: date_created>, is_next=True, **kwargs): Finds next instance based on date_created. See get_next_by_FOO() for more information.

get_outstanding_messages(user: User | None = None) → models.QuerySet[BrokerMessage]

Get the messages that still need to be send.

Parameters:: user (Optional[User]) – The user for whom to send the messages. If None, the messages will be returned that have not yet been acknowledged at all.
Returns:: A QuerySet of messages
Return type:: models.QuerySet[BrokerMessage]

get_previous_by_date_created(*, field=<django.db.models.DateTimeField: date_created>, is_next=False, **kwargs): Finds previous instance based on date_created. See get_previous_by_FOO() for more information.

get_store_messages_display(*, field=<django.db.models.CharField: store_messages>): Shows the label of the store_messages. See get_FOO_display() for more information.

get_websocket_url(request) → str: Get the websocket url for this topic.

id

Type: BigAutoField

Primary key: ID

A wrapper for a deferred-loading field. When the value is read from this

is_public

Type: BooleanField

Is public. Can everyone publish data to this topic?

A wrapper for a deferred-loading field. When the value is read from this

property is_response_topic: bool: Is this topic a responsetopic?

last_ping

Type: DateTimeField

Last ping. When has the topic last been pinged?

A wrapper for a deferred-loading field. When the value is read from this

last_pong

Type: DateTimeField

Last pong. When has the topic last replyed on a ping?

A wrapper for a deferred-loading field. When the value is read from this

objects = <dasf_broker.models.BrokerTopicManager object>

ping(): Create a ping message and send it to the consumer.

property producers: models.QuerySet[User]

responsetopic

Type: Reverse OneToOneField from ResponseTopic

The response topic of this broker topic (related name of brokertopic_ptr)

Accessor to the related object on the reverse side of a one-to-one relation.

In the example:

class Restaurant(Model):
    place = OneToOneField(Place, related_name='restaurant')

responsetopics

Type: Reverse ForeignKey from ResponseTopic

All responsetopics of this broker topic (related name of is_response_for)

Accessor to the related objects manager on the reverse side of a many-to-one relation.

In the example:

class Child(Model):
    parent = ForeignKey(Parent, related_name='children')

Parent.children is a ReverseManyToOneDescriptor instance.

Most of the implementation is delegated to a dynamically defined manager

slug

Type: SlugField

Slug. Unique identifier for the topic.

A wrapper for a deferred-loading field. When the value is read from this

property status_viewers: models.QuerySet[User]

store_messages

Type: CharField

Store messages. Should messages be stored?

Choices:

None
disabled
cache
cacheall
store

A wrapper for a deferred-loading field. When the value is read from this

supports_dasf

Type: BooleanField

Supports dasf. Does this topic support the DASF messaging protocoll?

A wrapper for a deferred-loading field. When the value is read from this

class dasf_broker.models.BrokerTopicManager(*args, **kwargs)

Bases: ManagerFromBrokerTopicQuerySet

A manager for broker topics.

class dasf_broker.models.BrokerTopicQuerySet(model=None, query=None, using=None, hints=None)

Bases: QuerySet

A queryset for broker topics.

Methods:

`filter_offline`(*args)	Query all online broker topics.
`filter_online`(args, *kwargs)	Query all online broker topics.
`filter_unknown_availability`(*args)	Query all topics where the availability is unknown.

filter_offline(*args): Query all online broker topics.

filter_online(*args, **kwargs): Query all online broker topics.

filter_unknown_availability(*args): Query all topics where the availability is unknown.

class dasf_broker.models.ResponseTopic(*args, **kwargs)

Bases: BrokerTopic

A topic that accepts responses for messages.

Parameters:

id (BigAutoField) – Primary key: ID
slug (SlugField) – Slug. Unique identifier for the topic.
is_public (BooleanField) – Is public. Can everyone publish data to this topic?
date_created (DateTimeField) – Date created. The date and time when the message has been created
last_ping (DateTimeField) – Last ping. When has the topic last been pinged?
last_pong (DateTimeField) – Last pong. When has the topic last replyed on a ping?
supports_dasf (BooleanField) – Supports dasf. Does this topic support the DASF messaging protocoll?
store_messages (CharField) – Store messages. Should messages be stored?
garbage_collect_on (DateTimeField) – Garbage collect on. Specify a time when this topic should be removed from the database.
api_info (JSONField) –
Api info

metadata field to allow additional attributes for topics.

Relationship fields:

Parameters:

brokertopic_ptr (OneToOneField to BrokerTopic) – Primary key: Brokertopic ptr (related name: responsetopic)
is_response_for (ForeignKey to BrokerTopic) – Is response for. Is this topic used only once for a single response? (related name: responsetopics)
source_messages (ManyToManyField to BrokerMessage) – Source messages. Messages from the producer to the reference topic. (related name: responsetopic)

Reverse relationships:

Parameters:

brokermessage (Reverse ForeignKey from BrokerMessage) – All broker messages of this broker topic (related name of topic)
responsetopics (Reverse ForeignKey from ResponseTopic) – All responsetopics of this broker topic (related name of is_response_for)

Miscellaneous:

`DoesNotExist`
`MultipleObjectsReturned`

Model Fields:

`brokertopic_ptr`	Type: `OneToOneField` to `BrokerTopic`
`is_response_for`	Type: `ForeignKey` to `BrokerTopic`

Attributes:

`brokertopic_ptr_id`	Internal field, use `brokertopic_ptr` instead.
`is_response_for_id`	Internal field, use `is_response_for` instead.
`is_response_topic`	Is this topic a responsetopic?
`source_messages`	Type: `ManyToManyField` to `BrokerMessage`

exception DoesNotExist: Bases: DoesNotExist

exception MultipleObjectsReturned: Bases: MultipleObjectsReturned

brokertopic_ptr: BrokerTopic

Type: OneToOneField to BrokerTopic

Primary key: Brokertopic ptr (related name: responsetopic)

Accessor to the related object on the forward side of a one-to-one relation.

In the example:

class Restaurant(Model):
    place = OneToOneField(Place, related_name='restaurant')

brokertopic_ptr_id: Internal field, use brokertopic_ptr instead.

is_response_for

Type: ForeignKey to BrokerTopic

Is response for. Is this topic used only once for a single response? (related name: responsetopics)

Accessor to the related object on the forward side of a many-to-one or one-to-one (via ForwardOneToOneDescriptor subclass) relation.

In the example:

class Child(Model):
    parent = ForeignKey(Parent, related_name='children')

is_response_for_id: Internal field, use is_response_for instead.

property is_response_topic: bool: Is this topic a responsetopic?

source_messages

Type: ManyToManyField to BrokerMessage

Source messages. Messages from the producer to the reference topic. (related name: responsetopic)

Accessor to the related objects manager on the forward and reverse sides of a many-to-many relation.

In the example:

class Pizza(Model):
    toppings = ManyToManyField(Topping, related_name='pizzas')

Pizza.toppings and Topping.pizzas are ManyToManyDescriptor instances.

Most of the implementation is delegated to a dynamically defined manager