Merge pull request #1376 from rstudio/use-empty-table

Use empty table as starting point for a gt table

.Rbuildignore

@@ -28,6 +28,7 @@ tests/testthat/test-cols_merge.R
 tests/testthat/test-cols_width_rtf.R
 tests/testthat/test-cols_width.R
 tests/testthat/test-data_color.R
+tests/testthat/test-empty_tbl.R
 tests/testthat/test-escaping.R
 tests/testthat/test-extract_cells.R
 tests/testthat/test-fmt_auto.R

R/build_data.R

@@ -30,6 +30,12 @@ build_data <- function(data, context) {
   # Perform input object validation
   stop_if_not_gt_tbl(data = data)
 
+  # For an empty table, ensure that some basic
+  # messaging is in place
+  if (is_gt_tbl_empty(data = data)) {
+    data <- adjust_gt_tbl_empty(data = data)
+  }
+
   # Create `body` with rendered values; move
   # input data cells to `body` that didn't have
   # any rendering applied during `render_formats()`;

R/dt_data.R

@@ -40,6 +40,11 @@ dt_data_init <- function(
     rownames_to_column = NA
 ) {
 
+  # If the data table has rows but no columns, remove all of the rows
+  if (ncol(data_tbl) == 0 && nrow(data_tbl) > 0) {
+    data_tbl <- data_tbl[0, ]
+  }
+
   if (!is.na(rownames_to_column)) {
 
     data_rownames <- rownames(data_tbl)
@@ -166,8 +171,8 @@ dt_data_add_rows <- function(
     if (is.null(stub_df_add[i, ][["group_label"]][[1]])) {
 
       if (
-        stub_df_add[i, ][["group_id"]] %in%
-        stub_df_group_lookup[["group_id"]]
+        length(stub_df_group_lookup[["group_id"]]) > 0 &&
+        stub_df_add[i, ][["group_id"]] %in% stub_df_group_lookup[["group_id"]]
       ) {
 
         # This case is where a `group_id` in the added rows already exists
@@ -180,9 +185,12 @@ dt_data_add_rows <- function(
 
       } else {
 
-        # Migrate the text from a new group ID to a group label
-        stub_df_add[i, ][["group_label"]] <-
-          as.list(stub_df_add[i, ][["group_id"]])
+        if (!is.na(stub_df_add[i, ][["group_id"]])) {
+
+          # Migrate the text from a new group ID to a group label
+          stub_df_add[i, ][["group_label"]] <-
+            as.list(stub_df_add[i, ][["group_id"]])
+        }
       }
     }
   }

R/dt_stub_df.R

@@ -53,6 +53,13 @@ dt_stub_df_init <- function(
       built_group_label = rep(NA_character_, nrow(data_tbl))
     )
 
+  # Handle case where table has no columns
+  if (ncol(data_tbl) < 1) {
+
+    data <- dt_stub_df_set(data = data, stub_df = stub_df)
+    return(data)
+  }
+
   #
   # Handle column of data specified as the `rowname_col`
   #

R/modify_columns.R

@@ -1793,6 +1793,114 @@ cols_add <- function(
   data_tbl <- dt_data_get(data = .data)
   data_tbl_columns <- colnames(data_tbl)
 
+  #
+  # Special case where data table has no columns (and perhaps no rows); here,
+  # we allow for one or more columns to be added with an arbitrary number of
+  # rows, however, the number of rows should be consistent across the supplied
+  # columns
+  #
+
+  if (nrow(data_tbl) < 1 && ncol(data_tbl) < 1) {
+
+    # Generate boxhead rows that correspond to the new columns
+    updated_boxh_df <-
+      dt_boxhead_get(data = gt(dplyr::as_tibble(as.data.frame(list(...)))))
+
+    # Modify the internal boxhead data frame
+    .data <- dt_boxhead_set(data = .data, boxh = updated_boxh_df)
+
+    # Manually add rows to the empty data table (if there are indeed some rows)
+    if (nrow(dplyr::as_tibble(as.data.frame(list(...)))) > 0) {
+
+      .data <-
+        dt_data_add_rows(
+          data = .data,
+          row_data_list = list(...),
+          before = NULL,
+          after = NULL
+        )
+    }
+
+    # Update the internal data table object
+    .data <-
+      dt_data_set(
+        data = .data,
+        data_tbl = dplyr::as_tibble(as.data.frame(list(...)))
+      )
+
+    return(.data)
+  }
+
+  #
+  # Special case where data table has some columns (but no rows); here, we allow
+  # for one or more columns to be added with an arbitrary number of rows,
+  # however, the number of rows should be consistent across the supplied columns
+  #
+
+  if (nrow(data_tbl) < 1 && ncol(data_tbl) > 0) {
+
+    # Generate boxhead rows that correspond to the new columns
+    updated_boxh_df <-
+      dt_boxhead_get(data = gt(dplyr::as_tibble(as.data.frame(list(...)))))
+
+    updated_boxh_df <-
+      dplyr::bind_rows(
+        dt_boxhead_get(data = .data),
+        updated_boxh_df[
+          !(updated_boxh_df$var %in% dt_boxhead_get(data = .data)[["var"]]),
+        ]
+      )
+
+    # Modify the internal boxhead data frame
+    .data <- dt_boxhead_set(data = .data, boxh = updated_boxh_df)
+
+    # Determine whether the supplied set of values is zero length
+    row_data_list_empty <-
+      all(
+        vapply(
+          seq_along(list(...)),
+          FUN.VALUE = logical(1),
+          USE.NAMES = FALSE,
+          FUN = function(x) {
+            length(list(...)[[x]]) < 1
+          }
+        )
+      )
+
+    if (row_data_list_empty) {
+
+      # Bind the zero-row tables together
+      updated_data_tbl <-
+        dplyr::bind_cols(
+          dt_data_get(data = .data),
+          dplyr::as_tibble(as.data.frame(list(...)))
+        )
+
+      # Update the internal data table object
+      .data <-
+        dt_data_set(
+          data = .data,
+          data_tbl = updated_data_tbl
+        )
+
+      return(.data)
+    }
+
+    # Manually add rows to the empty data table (if there are indeed some rows)
+    if (nrow(dplyr::as_tibble(as.data.frame(list(...)))) > 0) {
+
+      .data <-
+        dt_data_add_rows(
+          data = .data,
+          row_data_list = list(...),
+          before = NULL,
+          after = NULL
+        )
+    }
+
+    return(.data)
+  }
+
   # Mutate the internal data table and get a vector of its column names
   data_tbl_mutated <- dplyr::mutate(data_tbl, ...)
   data_tbl_mutated_columns <- colnames(data_tbl_mutated)
@@ -1813,7 +1921,8 @@ cols_add <- function(
   columns_new <- base::setdiff(data_tbl_mutated_columns, data_tbl_columns)
 
   # Generate a table that has only the new columns
-  data_tbl_new_cols <- dplyr::select(data_tbl_mutated, columns_new)
+  data_tbl_new_cols <-
+    dplyr::select(data_tbl_mutated, dplyr::all_of(columns_new))
 
   # Generate boxhead rows that correspond to the new columns
   boxh_df_new_cols <- dt_boxhead_get(data = gt(data_tbl_new_cols))

R/rows_add.R

@@ -307,8 +307,21 @@ rows_add <- function(
     return(.data)
   }
 
-  # Get the column names from the internal dataset
+  # Get the internal dataset and a vector of its column names
   data_tbl <- dt_data_get(data = .data)
+  data_tbl_columns <- colnames(data_tbl)
+
+  #
+  # Special case where data table has no columns (and no rows); here, we allow
+  # for one or more rows to be added with an arbitrary number of columns
+  #
+
+  if (nrow(data_tbl) < 1 && length(data_tbl_columns) < 1) {
+
+    .data <- cols_add(.data = .data, ...)
+
+    return(.data)
+  }
 
   if (!is.null(.n_empty)) {
 
@@ -453,6 +466,27 @@ rows_add <- function(
     cli::cli_abort("Expressions cannot be given to both `.before` and `.after`.")
   }
 
+  #
+  # Special case where all components of `row_data_list` are empty (have
+  # zero length); in this case we need to return the data unchanged
+  #
+
+  row_data_list_empty <-
+    all(
+      vapply(
+        seq_along(row_data_list),
+        FUN.VALUE = logical(1),
+        USE.NAMES = FALSE,
+        FUN = function(x) {
+          length(row_data_list[[x]]) < 1
+        }
+      )
+    )
+
+  if (row_data_list_empty) {
+    return(.data)
+  }
+
   dt_data_add_rows(
     data = .data,
     row_data_list = row_data_list,

R/utils.R

@@ -47,6 +47,37 @@ is_gt_tbl_or_group <- function(data) {
   inherits(data, "gt_tbl") || inherits(data, "gt_group")
 }
 
+is_gt_tbl_empty <- function(data) {
+  data_tbl <- dt_data_get(data = data)
+  ncol(data_tbl) == 0 && nrow(data_tbl) == 0
+}
+
+is_gt_tbl_empty_w_cols <- function(data) {
+  data_tbl <- dt_data_get(data = data)
+  ncol(data_tbl) > 0 && nrow(data_tbl) == 0
+}
+
+is_gt_tbl_empty_w_rows <- function(data) {
+  data_tbl <- dt_data_get(data = data)
+  ncol(data_tbl) == 0 && nrow(data_tbl) > 0
+}
+
+# Adjustments for a completely empty table (no columns and no rows)
+adjust_gt_tbl_empty <- function(data) {
+
+  # Get the table's locale
+  tbl_locale <- dt_locale_get_value(data = data)
+
+  no_table_data_text <- get_locale_no_table_data_text(locale = tbl_locale)
+
+  data <- cols_add(data, no_data = no_table_data_text)
+  data <- tab_options(data, column_labels.hidden = TRUE)
+  data <- cols_align(data, align = "center", columns = no_data)
+  data <- cols_width(data, no_data ~ px(500))
+
+  data
+}
+
 #' Determines whether a character vector is non-empty
 #'
 #' @param x A character vector.

R/utils_formatters.R

@@ -245,6 +245,23 @@ get_locale_num_spellout <- function(locale = NULL) {
   spelled_num[[locale]]
 }
 
+#' Get the `no_table_data_text` value based on a locale
+#'
+#' @param locale The user-supplied `locale` value, found in several `fmt_*()`
+#'   functions. This is expected as `NULL` if not supplied by the user.
+#' @noRd
+get_locale_no_table_data_text <- function(locale = NULL) {
+
+  # If `locale` is NULL then use the 'en' locale
+  if (is.null(locale)) {
+    locale <- "en"
+  }
+
+  # Get the correct `no_table_data_text` value from the
+  # `gt:::locales` lookup table
+  filter_table_to_value(locales, no_table_data_text, locale == {{ locale }})
+}
+
 get_locale_segments <- function(locale) {
 
   if (!grepl("-", locale)) {

data-raw/X03-locales.R

@@ -255,6 +255,19 @@ for (i in seq_along(regional_currencies)) {
 # Make corrections for specific currencies
 regional_currencies_tbl[regional_currencies_tbl$territory_name == "CU", ][["currency_code"]] <- "CUP"
 
+#
+# Create a table of 'no-table-data' text from all possible languages
+#
+
+no_table_data <-
+  readr::read_csv(
+    "data-raw/no_table_data_text.csv",
+    col_types = cols(
+      lang_name = col_character(),
+      no_table_data_text = col_character()
+    )
+  )
+
 #
 # Join all tables together to generate a comprehensive locale metadata table
 #
@@ -263,7 +276,8 @@ locales <-
   locale_metadata_tbl %>%
   left_join(chr_index_tbl, by = "locale") %>%
   left_join(numbers_metadata_tbl, by = "locale") %>%
-  left_join(regional_currencies_tbl, by = "territory_name")
+  left_join(regional_currencies_tbl, by = "territory_name") %>%
+  left_join(no_table_data, by = "lang_name")
 
 rm(parse_locale)
 rm(i)
@@ -292,3 +306,5 @@ rm(currency_in_use)
 rm(index_chr)
 rm(n_regional_currencies)
 rm(not_tender_j)
+rm(no_table_data)
+