Fix #1153

DESCRIPTION

@@ -12,7 +12,7 @@ Description: Pipeline tools coordinate the pieces of computationally
   The methodology in this package
   borrows from GNU 'Make' (2015, ISBN:978-9881443519)
   and 'drake' (2018, <doi:10.21105/joss.00550>).
-Version: 1.3.0.9000
+Version: 1.3.0.9001
 License: MIT + file LICENSE
 URL: https://docs.ropensci.org/targets/, https://github.com/ropensci/targets
 BugReports: https://github.com/ropensci/targets/issues

NAMESPACE

@@ -370,8 +370,10 @@ export(tar_callr_inner_try)
 export(tar_cancel)
 export(tar_canceled)
 export(tar_config_get)
+export(tar_config_projects)
 export(tar_config_set)
 export(tar_config_unset)
+export(tar_config_yaml)
 export(tar_counter)
 export(tar_crew)
 export(tar_cue)

NEWS.md

@@ -1,5 +1,6 @@
-# targets 1.3.0.9000 (development)
+# targets 1.3.0.9001 (development)
 
+* Add `tar_config_projects()` and `tar_config_yaml()` (#1153, @psychelzh).
 
 # targets 1.3.0
 

R/tar_config_get.R

@@ -38,7 +38,7 @@ tar_config_get <- function(
   tar_assert_scalar(project)
   choices <- setdiff(names(formals(tar_config_set)), c("config", "project"))
   tar_assert_flag(name, choices = choices)
-  yaml <- tar_config_read_yaml(config)
+  yaml <- tar_config_yaml(config)
   value <- if_any(
     tar_config_is_multi_project(yaml, config),
     tar_config_get_multi_project(name, yaml, project, memory_init()),

R/tar_config_list.R

@@ -0,0 +1,18 @@
+#' @title List projects.
+#' @export
+#' @family configuration
+#' @description List the names of projects defined in `_targets.yaml`.
+#' @return Character vector of names of projects defined in `_targets.yaml`.
+#' @inheritSection tar_meta Storage access
+#' @inheritSection tar_config_set Configuration
+#' @inheritParams tar_config_set
+#' @examples
+#' yaml <- tempfile()
+#' tar_config_set(store = "my_store_a", config = yaml, project = "project_a")
+#' tar_config_set(store = "my_store_b", config = yaml, project = "project_b")
+#' tar_config_projects(config = yaml)
+tar_config_projects <- function(
+  config = Sys.getenv("TAR_CONFIG", "_targets.yaml")
+) {
+  names(tar_config_yaml(config = config))
+}

R/tar_config_set.R

@@ -200,10 +200,7 @@ tar_config_set <- function(
   tar_config_assert_store(store)
   tar_config_assert_use_crew(use_crew)
   tar_config_assert_workers(workers)
-  yaml <- tar_config_read_yaml(config)
-  if (!tar_config_is_multi_project(yaml, config)) {
-    yaml <- tar_config_convert_multi_project(yaml, config)
-  }
+  yaml <- tar_config_yaml(config = config)
   yaml[[project]]$inherits <- inherits %|||% yaml[[project]]$inherits
   yaml[[project]]$garbage_collection <- garbage_collection %|||%
     yaml[[project]]$garbage_collection

R/tar_config_yaml.R

@@ -0,0 +1,25 @@
+#' @title Read `_targets.yaml`.
+#' @export
+#' @family configuration
+#' @description Read the YAML content of `_targets.yaml`.
+#' @return Nested list of fields defined in `_targets.yaml`.
+#' @inheritSection tar_meta Storage access
+#' @inheritSection tar_config_set Configuration
+#' @inheritParams tar_config_set
+#' @examples
+#' yaml <- tempfile()
+#' tar_config_set(store = "my_store_a", config = yaml, project = "project_a")
+#' tar_config_set(store = "my_store_b", config = yaml, project = "project_b")
+#' str(tar_config_yaml(config = yaml))
+tar_config_yaml <- function(
+  config = Sys.getenv("TAR_CONFIG", "_targets.yaml")
+) {
+  tar_assert_chr(config)
+  tar_assert_scalar(config)
+  yaml <- tar_config_read_yaml(config)
+  if_any(
+    tar_config_is_multi_project(yaml, config),
+    yaml,
+    tar_config_convert_multi_project(yaml, config)
+  )
+}

tests/testthat/test-tar_config_projects.R

@@ -0,0 +1,7 @@
+test_that("tar_config_projects()", {
+  yaml <- tempfile()
+  tar_config_set(store = "my_store_a", config = yaml, project = "project_a")
+  tar_config_set(store = "my_store_b", config = yaml, project = "project_b")
+  out <- tar_config_projects(config = yaml)
+  expect_equal(sort(out), sort(c("project_a", "project_b")))
+})

tests/testthat/test-tar_config_yaml.R

@@ -0,0 +1,11 @@
+test_that("tar_config_projects()", {
+  yaml <- tempfile()
+  tar_config_set(store = "my_store_a", config = yaml, project = "project_a")
+  tar_config_set(store = "my_store_b", config = yaml, project = "project_b")
+  out <- tar_config_yaml(config = yaml)
+  exp <- list(
+    project_a = list(store = "my_store_a"),
+    project_b = list(store = "my_store_b")
+  )
+  expect_equal(out, exp)
+})