move method for tune_args() from tune to here

DESCRIPTION

@@ -20,7 +20,7 @@ Depends:
 Imports: 
     cli (>= 2.0.0),
     ellipsis (>= 0.2.0),
-    generics (>= 0.1.0),
+    generics (>= 0.1.0.9000),
     glue,
     hardhat (>= 0.1.6),
     lifecycle (>= 1.0.0),

R/generics.R

@@ -27,3 +27,19 @@ required_pkgs.workflow <- function(x, infra = TRUE, ...) {
   out <- unique(out)
   out
 }
+
+# Lazily registered in .onLoad()
+tune_args_workflow <- function(object, ...) {
+  model <- extract_spec_parsnip(object)
+
+  param_data <- generics::tune_args(model)
+
+  if (has_preprocessor_recipe(object)) {
+    recipe <- extract_preprocessor(object)
+    recipe_param_data <- generics::tune_args(recipe)
+    param_data <- vctrs::vec_rbind(param_data, recipe_param_data)
+  }
+
+  param_data
+}
+

R/reexports.R

@@ -21,4 +21,3 @@ hardhat::extract_mold
 #' @importFrom hardhat extract_preprocessor
 #' @export
 hardhat::extract_preprocessor
-#'

R/zzz.R

@@ -8,6 +8,18 @@
   vctrs::s3_register("butcher::axe_fitted", "workflow")
 
   vctrs::s3_register("generics::required_pkgs", "workflow")
+
+  # - If tune isn't installed, register the method (`packageVersion()` will error here)
+  # - If tune >= 0.1.6.9001 is installed, register the method
+  should_register_tune_args_method <- tryCatch(
+    expr = utils::packageVersion("tune") >= "0.1.6.9001",
+    error = function(cnd) TRUE
+  )
+
+  if (should_register_tune_args_method) {
+    # `tune_args.workflow()` moved from tune to workflows
+    vctrs::s3_register("generics::tune_args", "workflow", tune_args_workflow)
+  }
 }
 
 # nocov end