Blueprint.save is very hard to find / needs doc

[teh-cmc]

I want to save a blueprint to a file for later use (e.g. from another language).

Saving the blueprint from the viewer (Menu > Save blueprint) works fine, but doing it from code leads to issues:

import sys

import rerun as rr
import rerun.blueprint as rrb

path_to_rbl = sys.argv[1]

rr.init("rerun_example_dataframe")
rr.save(path_to_rbl)

blueprint = rrb.Blueprint(
    rrb.DataframeView(
        origin="/",
        query=rrb.archetypes.DataframeQuery(
            timeline="log_time",
            apply_latest_at=True,
        ),
    ),
)

rr.send_blueprint(blueprint)

# The output .rbl file now contains an empty data recording too :(

The problem is that this also initializes an empty data recording (i.e. SetStoreInfo is fired), and therefore loading that blueprint later one will create an empty recording in the viewer, switch focus to it, etc. Makes the whole workflow unusable in practice.

How can we only save the blueprint using the API?

[teh-cmc]

@jleibs tells me there is: https://ref.rerun.io/docs/python/0.19.0/common/blueprint_apis/#rerun.blueprint.Blueprint.save

It's just hard to find right now.

I'll slip a word regarding this in my upcoming "re-use blueprints across languages" thingy.