Best way to insert a custom TOC in officer - officer

Question

I need to insert a custom TOC into an officer document. In this case I need to insert a list of tables that are created using the level 6 headers. The TOC field I need to insert is:
{TOC \o "6-6" \* MERGEFORMAT}
The block_toc function doesn't seem to allow me to do this. So was thinking of doing is using the internal functions within that function (e.g., run_seqfield, to_wml, etc) to accomplish this. I was wondering if anyone had any other ideas that utilized the more standard officer functions.
In the example below I'm trying to create a list of tables using the style option with block_toc. When I run this it gives me "No table of contents entries found."
library(officer)
library(flextable)
library(magrittr)
tab_seq_id = "Table"
# empty report
rpt = read_docx()
bt <- block_toc(style = "Table Caption")
out <- to_wml(bt, add_ns = TRUE)
rpt <- body_add_xml(rpt, str = out, pos = "after")
mytxt = paste(rep("The quick brown fox jumped over the lazy dog.", 30), collapse=" ")
# Making a table
ft = flextable(head(mtcars))
# Creating some sections with text
rpt = body_add_fpar(rpt, fpar("A section"), style="heading 1")
fptxt = fpar(mytxt)
rpt = officer::body_add_fpar(rpt, fptxt)
rpt = body_add_fpar(rpt, fpar("Another section"), style="heading 1")
fptxt = fpar("This is a cross reference to the first table (Table ",
run_reference("my_table"),
") and this is a reference to the second table (Table ",
run_reference("my_second_table"), ")." ,
") and a third table in a new section (Table ",
run_reference("my_third_table"), ")." )
long_cap = "This is my table caption. It can span many lines and take up much space on the page."
#-------------------------------------------------------
# Normal table
run_num = officer::run_autonum(seq_id = tab_seq_id,
pre_label = "Table ",
post_label = ".",
bkm = "my_table")
caption = officer::block_caption(long_cap,
style = "Table Caption",
autonum = run_num )
rpt = officer::body_add_fpar(rpt, fptxt)
rpt = flextable::body_add_flextable(rpt, value=ft)
rpt = officer::body_add_caption(rpt, caption)
#-------------------------------------------------------
# Table with the section number in it
runs = list(
run_word_field("STYLEREF 1 \\s"),
ftext("-"),
officer::run_autonum(pre_label = "", seq_id = tab_seq_id, post_label=""))
rb_res = run_bookmark("my_second_table", runs)
rpt = flextable::body_add_flextable(rpt, value=ft)
rpt = officer::body_add_fpar(rpt, fpar("Table ", rb_res, ". ", long_cap), style = "Table Caption")
# Creating some sections with text
rpt = body_add_fpar(rpt, fpar("A third section"), style="heading 1")
#-------------------------------------------------------
# Table with the section number in it
runs = list(
run_word_field("STYLEREF 1 \\s"),
ftext("-"),
officer::run_autonum(pre_label = "", seq_id = tab_seq_id, start_at = 1, post_label=""))
rb_res = run_bookmark("my_third_table", runs)
rpt = flextable::body_add_flextable(rpt, value=ft)
rpt = officer::body_add_fpar(rpt, fpar("Table ", rb_res, ". ", long_cap), style = "Table Caption")
print(rpt, "fig_sec_num.docx")

Answer 1

This should help (also remember to refresh the TOC from within Word):
library(officer)
library(flextable)
library(magrittr)
mytxt <- paste(rep("The quick brown fox jumped over the lazy dog.", 30), collapse = " ")
long_cap <- "This is my table caption. It can span many lines and take up much space on the page."
tab_seq_id <- "Table"
ft <- flextable(head(mtcars))
get_caption <- function(bookmark){
par <- list(
ftext("Table "),
run_word_field("STYLEREF 1 \\s"),
ftext("-"),
run_word_field("SEQ Table \u005C* Arabic")
)
run_bookmark(bookmark, par)
}
fptxt <- fpar(
"This is a cross reference to the first table (",
run_reference("my_table1"),
") and this is a reference to the second table (",
run_reference("my_table2"), ").",
") and a third table in a new section (",
run_reference("my_table3"), ")."
)
rpt <- read_docx() %>%
body_add_toc(style = "Table Caption") %>%
body_add_par("A section", style = "heading 1") %>%
body_add_par(value = mytxt, style = "Normal") %>%
body_add_par("Another section", style = "heading 1") %>%
body_add_fpar(fptxt) %>%
body_add_flextable(value = ft) %>%
body_add_fpar(value = fpar(get_caption(bookmark = "my_table1"), " ", long_cap), style = "Table Caption") %>%
body_add_flextable(value = ft) %>%
body_add_fpar(value = fpar(get_caption(bookmark = "my_table2"), " ", long_cap), style = "Table Caption") %>%
body_add_par("A third section", style = "heading 1") %>%
body_add_flextable(value = ft) %>%
body_add_fpar(value = fpar(get_caption(bookmark = "my_table3"), " ", long_cap), style = "Table Caption")
print(rpt, "fig_sec_num.docx")

Answer 2

TLDR; I need to add separator="," to body_add_toc() call above
I started looking at the TOC field codes are generated when specifying a Word Style. The example David provided worked on his computer but I couldn't get it to generate a TOC on my end. I started playing with the field codes that were generated to try to get at the problem. The field code that is generated by officer for me in Davids solution is:
{TOC \h \z \t "Table Caption;1"}
That wasn't working for me. Then I found that if I change the field code to one of the following it will generate the TOC correctly:
{TOC \h \z \t "Table Caption"}
{TOC \h \z \t "Table Caption,1"}
In the first example I'm omitting the ";1" completely and in the second example I'm changing ";" to ",". So I started googling and if I'm reading this correctly there is some kind of regional setting that may be causing this:
https://answers.microsoft.com/en-us/msoffice/forum/all/table-of-contents-word-2016-word-2013/842156d0-51dd-4726-9c36-343e57bf9f92
Then I read the documentation for body_add_toc and realized there is an option there for this very problem. I'd seen it before, but I had no idea why it was there, but that fixed everything for me.
Thanks for your patience David.