Removes a pipeline step by its name. If other steps depend on it,
an error is given and the removal of the step is blocked, unless
force was set to TRUE, which will remove the selected step
together with all its downstream dependent steps.
Note
If called on a view, the step to be removed must be part of the view,
since removing steps drops rows from the pipeline, the row positions
of the view will be shifted after the removal operation.
For views, you therefore need to assign the result back to the view:
v <- pip_remove(v, ...).
Views that are not reassigned (or other views on the same pipeline),
keep their old row positions and therefore can become invalid after a
step removal.
Examples
p <- pip_new() |>
pip_add("load", \(x = 1) x) |>
pip_add("transform", \(x = ~load) x * 2) |>
pip_add("model", \(x = ~transform) x + 10)
# Removing a leaf step (nothing depends on it) works directly
pip_remove(p, "model")
p # "load", "transform"
#> <pipeflow> pipe (2 steps)
#> -------------------------
#> step params depends state
#> 1: load x new
#> 2: transform x load new
#> -------------------------
#> <ready> last run: never
# Trying to remove a step that others depend on raises an error:
# pip_remove(p, "load") # Error!
# If a view is passed, the step must be part of the view.
v <- pip_view(p, step = "transform")
try(pip_remove(v, "load")) # Error: "load" is not part of the view
#> Error in pip_remove(v, "load") : step 'load' is not part of the view
v <- pip_remove(v, "transform")
v[["step"]] # view is remapped and stays valid
#> named character(0)
p # "load"
#> <pipeflow> pipe (1 step)
#> ------------------------
#> step params depends state
#> 1: load x new
#> ------------------------
#> <ready> last run: never
# force = TRUE removes the step and all its downstream dependents
pip_remove(p, "load", force = TRUE)
p # pipeline is now empty
#> <pipeflow> pipe (0 steps)
#> -------------------------
#> Empty pipeline
#> -------------------------
#> <ready> last run: never