Reducing the output from tar_outdated()

[TylerGrantSmith]

I find myself frequently not caring about all the targets which have become outdated, but only those targets/objects furthest upstream which are outdated. This would be particularly helpful in large pipelines where an early dependencies produces a large number of outdated nodes. Could an option be added to tar_outdated or perhaps a new function with this kind of functionality? Maybe I am the only one that has this concern, which is fine too.

In a similar vein, is it possible to identify or filter by the one-or-more causes of a target being outdated? e.g., did the command change, did the format change, did a dependency get outdated?

[wlandau]

tar_sitrep() does what I think you are describing.

library(targets)
tar_script(list(tar_target(x, 1), tar_target(y, x)))
tar_make()
#> • start target x
#> • built target x
#> • start target y
#> • built target y
#> • end pipeline
tar_script(list(tar_target(x, 2), tar_target(y, x))) # invalidate x

tar_sitrep()
#> # A tibble: 2 × 9
#>   name  record always never command depend format iteration file 
#>   <chr> <lgl>  <lgl>  <lgl> <lgl>   <lgl>  <lgl>  <lgl>     <lgl>
#> 1 x     FALSE  FALSE  FALSE TRUE    FALSE  FALSE  FALSE     FALSE
#> 2 y     FALSE  FALSE  FALSE FALSE   FALSE  FALSE  FALSE     FALSE

^{Created on 2021-11-17 by the reprex package (v2.0.1)}