Fmt txt. closes #107 (#607)

* provide fmt_txt() to style character strings

* add more arguments and cleanup

* Update NEWS

NAMESPACE

@@ -23,6 +23,7 @@ export(current_sheet)
 export(dataframe_to_dims)
 export(delete_data)
 export(dims_to_dataframe)
+export(fmt_txt)
 export(get_cell_refs)
 export(get_date_origin)
 export(get_named_regions)

NEWS.md

@@ -10,6 +10,8 @@
 
 * Import `tableStyles` with `wb_load()` and improve `dxf` style creation. [603](https://github.com/JanMarvin/openxlsx2/pull/603)
 
+* Add `fmt_txt()` to style character strings. [607](https://github.com/JanMarvin/openxlsx2/pull/607)
+
 
 ***************************************************************************
 

R/utils.R

@@ -291,3 +291,127 @@ read_xml_files <- function(x) {
          FUN.VALUE = NA_character_,
          USE.NAMES = FALSE)
 }
+
+#' format strings independent of the cell style.
+#' @details
+#' The result is an xml string. It is possible to paste multiple `fmt_txt()`
+#' strings together to create a string with differing styles.
+#' @param x a string or part of a string
+#' @param bold bold
+#' @param italic italic
+#' @param underline underline
+#' @param strike strike
+#' @param size the font size
+#' @param color a wbColor color for the font
+#' @param font the font name
+#' @param charset integer value from the table below
+#' @param outline TRUE or FALSE
+#' @param vertAlign baseline, superscript, or subscript
+#' @details
+#'  |"Value" | "Character Set"      |
+#'  |--------|----------------------|
+#'  |"0"     | "ANSI_CHARSET"       |
+#'  |"1"     | "DEFAULT_CHARSET"    |
+#'  |"2"     | "SYMBOL_CHARSET"     |
+#'  |"77"    | "MAC_CHARSET"        |
+#'  |"128"   | "SHIFTJIS_CHARSET"   |
+#'  |"129"   | "HANGUL_CHARSET"     |
+#'  |"130"   | "JOHAB_CHARSET"      |
+#'  |"134"   | "GB2312_CHARSET"     |
+#'  |"136"   | "CHINESEBIG5_CHARSET"|
+#'  |"161"   | "GREEK_CHARSET"      |
+#'  |"162"   | "TURKISH_CHARSET"    |
+#'  |"163"   | "VIETNAMESE_CHARSET" |
+#'  |"177"   | "HEBREW_CHARSET"     |
+#'  |"178"   | "ARABIC_CHARSET"     |
+#'  |"186"   | "BALTIC_CHARSET"     |
+#'  |"204"   | "RUSSIAN_CHARSET"    |
+#'  |"222"   | "THAI_CHARSET"       |
+#'  |"238"   | "EASTEUROPE_CHARSET" |
+#'  |"255"   | "OEM_CHARSET"        |
+#' @examples
+#' fmt_txt("bar", underline = TRUE)
+#' @export
+fmt_txt <- function(
+    x,
+    bold      = FALSE,
+    italic    = FALSE,
+    underline = FALSE,
+    strike    = FALSE,
+    size      = NULL,
+    color     = NULL,
+    font      = NULL,
+    charset   = NULL,
+    outline   = NULL,
+    vertAlign = NULL
+) {
+
+  xml_b     <- NULL
+  xml_i     <- NULL
+  xml_u     <- NULL
+  xml_strk  <- NULL
+  xml_sz    <- NULL
+  xml_color <- NULL
+  xml_font  <- NULL
+  xml_chrst <- NULL
+  xml_otln  <- NULL
+  xml_vrtln <- NULL
+
+  if (bold) {
+    xml_b <-  xml_node_create("b")
+  }
+  if (italic) {
+    xml_i <-  xml_node_create("i")
+  }
+  if (underline) {
+    xml_u <-  xml_node_create("u")
+  }
+  if (strike) {
+    xml_strk <- xml_node_create("strike")
+  }
+  if (length(size)) {
+    xml_sz <- xml_node_create("sz", xml_attributes = c(val = as_xml_attr(size)))
+  }
+  if (inherits(color, "wbColour")) {
+    xml_color <- xml_node_create("color", xml_attributes = color)
+  }
+  if (length(font)) {
+    xml_font <- xml_node_create("rFont", xml_attributes = c(val = font))
+  }
+  if (length(charset)) {
+    xml_chrst <- xml_node_create("charset", xml_attributes = c("val" = charset))
+  }
+  if (length(outline)) {
+    xml_otln <- xml_node_create("outline", xml_attributes = c("val" = as_xml_attr(outline)))
+  }
+  if (length(vertAlign)) {
+    xml_vrtln <- xml_node_create("vertAlign", xml_attributes = c("val" = as_xml_attr(vertAlign)))
+  }
+
+  xml_t_attr <- if (grepl("(^\\s+)|(\\s+$)", x)) c("xml:space" = "preserve") else NULL
+  xml_t <- xml_node_create("t", xml_children = x, xml_attributes = xml_t_attr)
+
+  xml_rpr <- xml_node_create(
+    "rPr",
+    xml_children = c(
+      xml_b,
+      xml_i,
+      xml_u,
+      xml_strk,
+      xml_sz,
+      xml_color,
+      xml_font,
+      xml_chrst,
+      xml_otln,
+      xml_vrtln
+    )
+  )
+
+  xml_node_create(
+    "r",
+    xml_children = c(
+      xml_rpr,
+      xml_t
+    )
+  )
+}

src/strings_xml.cpp

@@ -112,14 +112,22 @@ std::string txt_to_xml(
 
   pugi::xml_node is_node = doc.append_child(type.c_str());
 
-  // text to export
-  pugi::xml_node t_node = is_node.append_child("t");;
+  pugi::xml_document txt_node;
+  pugi::xml_parse_result result = txt_node.load_string(text.c_str(), pugi::parse_default | pugi::parse_ws_pcdata | pugi::parse_escapes);
 
-  if ((text.size() > 0) && (std::isspace(text.at(0)) || std::isspace(text.at(text.size()-1)))) {
-    t_node.append_attribute("xml:space").set_value("preserve");
-  }
+  if (result) {
+    for (auto is_n : txt_node.children())
+          is_node.append_copy(is_n);
+  } else {
+    // text to export
+    pugi::xml_node t_node = is_node.append_child("t");
 
-  t_node.append_child(pugi::node_pcdata).set_value(text.c_str());
+    if ((text.size() > 0) && (std::isspace(text.at(0)) || std::isspace(text.at(text.size()-1)))) {
+      t_node.append_attribute("xml:space").set_value("preserve");
+    }
+
+    t_node.append_child(pugi::node_pcdata).set_value(text.c_str());
+  }
 
   std::ostringstream oss;
   doc.print(oss, " ", pugi_format_flags);

tests/testthat/test-utils.R

@@ -113,3 +113,25 @@ test_that("as_xml_attr works", {
   expect_equal(exp, mm)
 
 })
+
+test_that("string formating", {
+
+  foo <- fmt_txt("foo: ", bold = TRUE, size = 16, color = wb_color("green"))
+  bar <- fmt_txt("bar", underline = TRUE)
+  txt <- paste0(foo, bar)
+
+  exp <- "<is><r><rPr><b/><sz val=\"16\"/><color rgb=\"FF00FF00\"/></rPr><t xml:space=\"preserve\">foo: </t></r></is>"
+  got <- txt_to_is(foo)
+  expect_equal(exp, got)
+
+  exp <- "<si><r><rPr><b/><sz val=\"16\"/><color rgb=\"FF00FF00\"/></rPr><t xml:space=\"preserve\">foo: </t></r></si>"
+  got <- txt_to_si(foo)
+  expect_equal(exp, got)
+
+  wb <- wb_workbook()$add_worksheet()$add_data(x = data.frame(txt))
+
+  exp <- "foo: bar"
+  got <- wb_to_df(wb)$txt
+  expect_equal(exp, got)
+
+})