Topics#

Define API Topics.

class gcloud.pubsub.topic.Batch(topic, client)[source]#

Context manager: collect messages to publish via a single API call.

Helper returned by :meth:Topic.batch

Parameters:	topic (`gcloud.pubsub.topic.Topic`) – the topic being published client (`gcloud.pubsub.client.Client`) – The client to use.

commit(client=None)[source]#

Send saved messages as a single API call.

Parameters:	client (`gcloud.pubsub.client.Client` or `NoneType`) – the client to use. If not passed, falls back to the `client` stored on the current batch.

publish(message, **attrs)[source]#

Emulate publishing a message, but save it.

Parameters:	message (bytes) – the message payload attrs (dict (string -> string)) – key-value pairs to send as message attributes

class gcloud.pubsub.topic.Topic(name, client, timestamp_messages=False)[source]#

Topics are targets to which messages can be published.

Subscribers then receive those messages.

Parameters:	name (string) – the name of the topic client (`gcloud.pubsub.client.Client`) – A client which holds credentials and project configuration for the topic (which requires a project). timestamp_messages (boolean) – If true, the topic will add a `timestamp` key to the attributes of each published message: the value will be an RFC 3339 timestamp.

batch(client=None)[source]#

Return a batch to use as a context manager.

Parameters:	client (`gcloud.pubsub.client.Client` or `NoneType`) – the client to use. If not passed, falls back to the `client` stored on the current topic.
Return type:	`Batch`
Returns:	A batch to use as a context manager.

create(client=None)[source]#

API call: create the topic via a PUT request

Parameters:	client (`gcloud.pubsub.client.Client` or `NoneType`) – the client to use. If not passed, falls back to the `client` stored on the current topic.

delete(client=None)[source]#

API call: delete the topic via a DELETE request

Parameters:	client (`gcloud.pubsub.client.Client` or `NoneType`) – the client to use. If not passed, falls back to the `client` stored on the current topic.

exists(client=None)[source]#

API call: test for the existence of the topic via a GET request

Parameters:	client (`gcloud.pubsub.client.Client` or `NoneType`) – the client to use. If not passed, falls back to the `client` stored on the current topic.

classmethod from_api_repr(resource, client)[source]#

Factory: construct a topic given its API representation

Parameters:	resource (dict) – topic resource representation returned from the API client (`gcloud.pubsub.client.Client`) – Client which holds credentials and project configuration for the topic.
Return type:	`gcloud.pubsub.topic.Topic`
Returns:	Topic parsed from `resource`.
Raises:	`ValueError` if `client` is not `None` and the project from the resource does not agree with the project from the client.

publish(message, client=None, **attrs)[source]#

API call: publish a message to a topic via a POST request

Parameters:	message (bytes) – the message payload client (`gcloud.pubsub.client.Client` or `NoneType`) – the client to use. If not passed, falls back to the `client` stored on the current topic. attrs (dict (string -> string)) – key-value pairs to send as message attributes
Return type:	str
Returns:	message ID assigned by the server to the published message

subscription(name, ack_deadline=None, push_endpoint=None)[source]#

Creates a subscription bound to the current topic.

Parameters:	name (string) – the name of the subscription ack_deadline (int) – the deadline (in seconds) by which messages pulled from the back-end must be acknowledged. push_endpoint (string) – URL to which messages will be pushed by the back-end. If not set, the application must pull messages.