Add possibility to interact with metadata

[olivroy]

Fix #744, #745

The implementation is quite basic. There is now potential duplication of code, with wb_add_creators(), wb_workbook(), but it is not too bad. Feel free to tweak the implementation.

This seems to fail without worksheets, but I wouldn't know why you wouldn't want to have a worksheet in a workbook
Lmk what you think.
This now works #741 (comment)

devtools::load_all("~/rrr-forks/openxlsx2")
#> ℹ Loading openxlsx2
wb1 <- wb_workbook(title = "thingy", subject = "A COOL SUBJECT")
wb1$add_worksheet()
wb1$open()
#> Warning in xl_open.default(x$clone()$save(temp_xlsx(macros = has_macros))$path,
#> : will not open file when not interactive
wb1$subject
#> [1] "A COOL SUBJECT"
wb1$set_properties(subject=  "A new subject")
wb1$subject
#> [1] "A new subject"
tmp_file <- temp_xlsx()
wb1$save(tmp_file)
wb2 <- wb_load(tmp_file)
wb2$subject
#> [1] "A new subject"
wb2$title
#> [1] "thingy"

edit: used the logic of wb$add_creator() mainly

[JanMarvin]

Cool! Thanks, even with a wrapper function! I'll have a closer look. Just for reference: I was thinking along the lines of this (this is quite general and should keep everything in wb$core that is not covered by genBaseCore():

library(openxlsx2)
# get some example file
wb <- wb_load(file = system.file("extdata", "openxlsx2_example.xlsx", package = "openxlsx2"))

#  get the core properties
get_core_propteries <- function(wb) {
  nams <- wb$core %>% xml_node_name("cp:coreProperties")
  vapply(nams, function(x)
    xml_value(wb$core, "cp:coreProperties", x), FUN.VALUE = NA_character_)
}

# set the core properties to replace genBaseCore()
set_core_properties <- function(wb, creator = NULL, title = NULL, subject = NULL, category = NULL) {
  
  # get an xml output or create one
  if (!is.null(wb$core)) {
    nams <- wb$core %>% xml_node_name("cp:coreProperties")
    xml_properties <- vapply(nams, function(x) {
      xml_value(wb$core, "cp:coreProperties", x)
    }, FUN.VALUE = NA_character_)
  } else {
    xml_properties <- c(
      "dc:creator" = "", 
      "cp:lastModifiedBy" = "",
      "dcterms:created" = "",
      "dcterms:modified" = "",
      "dc:title" = "",
      "dc:subject" = ""
    )
  }
  
  # update values where needed
  if (!is.null(creator)) {
    xml_properties["dc:creator"] <- as.character(creator)
  }
  if (!is.null(title)) {
    xml_properties["dc:title"] <- as.character(title)
  }
  if (!is.null(subject)) {
    xml_properties["dc:subject"] <- as.character(subject)
  }
  
  # create xml children
  xml_create_value <- mapply(function(x, y) {
    xml_node_create(x, xml_children = y)
  }, names(xml_properties), xml_properties)
  
  # return xml core output  
  xml_node_create(
    "cp:coreProperties",
    xml_attributes = c(
      "xmlns:cp"="http://schemas.openxmlformats.org/package/2006/metadata/core-properties",
      "xmlns:dc"="http://purl.org/dc/elements/1.1/",
      "xmlns:dcterms"="http://purl.org/dc/terms/",
      "xmlns:dcmitype"="http://purl.org/dc/dcmitype/",
      "xmlns:xsi"="http://www.w3.org/2001/XMLSchema-instance"
    ),
    xml_children = paste0(xml_create_value, collapse = "")
  )
  
}

get_core_propteries(wb)
#>             dc:creator      cp:lastModifiedBy        dcterms:created 
#> "Jan Marvin Garbuszus" "Jan Marvin Garbuszus" "2023-05-29T07:43:12Z" 
#>       dcterms:modified 
#> "2023-05-29T10:47:37Z"
set_core_properties(wb, creator = "olivroy") %>% as_xml()
#> <cp:coreProperties xmlns:cp="http://schemas.openxmlformats.org/package/2006/metadata/core-properties" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:dcterms="http://purl.org/dc/terms/" xmlns:dcmitype="http://purl.org/dc/dcmitype/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
#>  <dc:creator>olivroy</dc:creator>
#>  <cp:lastModifiedBy>Jan Marvin Garbuszus</cp:lastModifiedBy>
#>  <dcterms:created>2023-05-29T07:43:12Z</dcterms:created>
#>  <dcterms:modified>2023-05-29T10:47:37Z</dcterms:modified>
#> </cp:coreProperties>

[JanMarvin]

I don't have time to work on this this week ergo it will not make if for 1.0.

[olivroy]

That is fine.. Just wanted to get the ball rolling, but you're the pro with xml !

[JanMarvin]

I close this as superseded by #782 .