publish

The publish method publishes a source ticket to a result ticket. This is a low-level method that can be used to publish any server object (not just tables) to a shared ticket.

The source ticket represents a previously fetched server object to be published, and the result ticket (typically a SharedTicket) is the ticket to publish to. Other sessions can then fetched the result ticket to access the object as long as the object is not released.

This method is used together with the fetch method to share server objects between sessions.

Note

For tables specifically, use the higher-level publish_table method instead.

Important

Shared tickets have a life cycle tied to the source. Other Deephaven sessions can only fetch tickets to access the object as long as the object is not released. When the object is released either through an explicit call of the release method, implicitly through garbage collection, or through the closing of the publishing session, the shared ticket is no longer valid.

Syntax

publish(source_ticket: Ticket, result_ticket: Ticket) -> None

Parameters

Parameter	Type	Description
source_ticket	Ticket	The source ticket to publish from.
result_ticket	Ticket	The result ticket to publish to, typically a `SharedTicket`.

Returns

This method returns None.

Examples

Publishing a Figure object

The following example publishes a Figure (plot) object to a shared ticket so other sessions can access it.

from pydeephaven import Session
from pydeephaven.ticket import SharedTicket, ServerObject

# Create a session and generate a plot
session = Session(host="localhost", port=10000)
session.run_script("""
from deephaven.plot.figure import Figure
from deephaven import empty_table

source = empty_table(20).update([
    "X = 0.1 * i",
    "Y = randomDouble(0.0, 5.0)"
])

plot = Figure().plot_xy(
    series_name="Random numbers",
    t=source,
    x="X",
    y="Y"
).show()
""")

# Get the plot object from the session
plot_obj = session.exportable_objects["plot"]

# Create a plugin client to interact with the plot
plugin_client = session.plugin_client(plot_obj)

# Fetch the plugin object to get an export ticket
export_ticket = session.fetch(plugin_client)

# Publish the plot to a shared ticket
shared_ticket = SharedTicket.random_ticket()
session.publish(export_ticket, shared_ticket)

# Another session can now fetch this plot
sub_session = Session(host="localhost", port=10000)
server_obj = ServerObject(type="Figure", ticket=shared_ticket)
sub_plugin_client = sub_session.plugin_client(server_obj)

# The subscriber session can now interact with the plot
payload, refs = next(sub_plugin_client.resp_stream)

sub_plugin_client.close()
sub_session.close()
plugin_client.close()
session.close()

Publishing a table using generic publish

While publish_table is recommended for tables, you can also use the generic publish method:

from pydeephaven import Session
from pydeephaven.ticket import SharedTicket, ScopeTicket

# Create a session and table
session = Session(host="localhost", port=10000)
session.run_script("source = empty_table(20).update('X = i')")

# Fetch the table as an export ticket
export_ticket = session.fetch(ScopeTicket.scope_ticket("source"))

# Publish using the generic publish method
shared_ticket = SharedTicket.random_ticket()
session.publish(export_ticket, shared_ticket)

# Another session can fetch this table
sub_session = Session(host="localhost", port=10000)
table = sub_session.fetch_table(shared_ticket)

sub_session.close()
session.close()