Added csl_fields data prototype

.Rbuildignore

@@ -11,3 +11,4 @@ njtierney
 ^\.httr-oauth$
 ^_pkgdown\.yml$
 ^CRAN-RELEASE$
+^data-raw$

data-raw/csl_fields.R

@@ -0,0 +1,25 @@
+csl_types <- jsonlite::read_json("https://resource.citationstyles.org/schema/latest/input/json/csl-data.json")
+csl_fields <- csl_types$items$properties
+csl_field_type <- function(x) {
+  type <- x[["type"]][[1]]
+  if(is.null(type)) type <- sub("#/definitions/", "", x[["$ref"]], fixed = TRUE)
+  if(type == "array") {
+    x <- csl_field_type(x[["items"]])
+    if(vec_is(x, csl_names())) {
+      return(vctrs::new_list_of(ptype = x, class = "list_of_csl_names"))
+    } else {
+      # Too hard to convert to list_of for all types
+      return(list())
+    }
+  }
+  switch (type,
+          "string" = character(),
+          "number" = numeric(),
+          "name-variable" = csl_names(),
+          "date-variable" = csl_dates(),
+          "object" = list()
+  )
+}
+csl_fields <- tibble::as_tibble(lapply(csl_fields, csl_field_type))
+
+usethis::use_data(csl_fields, overwrite = TRUE, internal = TRUE)