Saving pipelines
A pipeline can be saved with saveRDS() and read back with readRDS()
(or serialized in other ways, e.g. to send it to another R process), with
its steps, parameters, outputs and states. The dependency graph of the
steps is kept outside of R and is not saved, but it is rebuilt from the
steps the first time it is needed. Views that are saved in the same object
as their pipeline, as in saveRDS(list(p, v), file), are read as views of
the read pipeline. A view that is saved on its own is read with its own
copy of the pipeline.
Examples
p <- pip_new("demo") |>
pip_add("numbers", \(n = 5) seq_len(n)) |>
pip_add("squared", \(x = ~numbers) x^2) |>
pip_add("total", \(x = ~squared) sum(x))
p
#> <pipeflow> demo (3 steps)
#> -------------------------
#> step params depends state
#> 1: numbers n new
#> 2: squared x numbers new
#> 3: total x squared new
#> -------------------------
#> <ready> last run: never
str(p)
#> List of 3
#> $ name : chr "demo"
#> $ view : NULL
#> $ pipenv:<environment: 0x556c5ba07988>
p[["name"]] # "demo"
#> [1] "demo"
p[["view"]] # initially NULL
#> NULL
# Inner pipeline environment (for advanced usage)
ls(p[["pipenv"]]) # shows "data"
#> [1] "data"
ls(p[["pipenv"]], all = TRUE) # also shows hidden variables
#> [1] ".dag" ".last_run" ".restart_count" ".restart_force"
#> [5] ".run_state" ".steps_to_nodes" "data"
# Save the pipeline and read it back
file <- tempfile(fileext = ".rds")
saveRDS(p, file)
p2 <- readRDS(file)
pip_run(p2)
#> info [2026-10-15 11:21:05.518 UTC]: Starting run of pipeflow 'demo'
#> info [2026-10-15 11:21:05.518 UTC]: Step 1/3 numbers
#> info [2026-10-15 11:21:05.518 UTC]: Step 2/3 squared
#> info [2026-10-15 11:21:05.520 UTC]: Step 3/3 total
#> info [2026-10-15 11:21:05.520 UTC]: Finished run of pipeflow 'demo'
p2
#> <pipeflow> demo (3 steps)
#> -------------------------
#> step params depends state out
#> 1: numbers n done 1,2,3,4,5
#> 2: squared x numbers done 1, 4, 9,16,25
#> 3: total x squared done 55
#> -------------------------
#> <ready> last run: 2026-10-15 11:21:05
unlink(file)