Indentation in the first column of a flextable object

Question

I am building flextable objects to show tables, and sometimes I would like to add one or several indentations in the first column, where I show some rows' names.

Next I share some code to simulate some data and have a reproducible example. The true starting point of my question is ft (Table 1):

library(dplyr)
library(flextable)

# Simulate data
g_A <- expand.grid(x = "A", y = c("A_1", "A_2"), z = c("A_1_a", "A_1_b", "A_2_a", "A_2_b"))
g_B <- expand.grid(x = "B", y = c("B_1", "B_2"), z = c("B_1_a", "B_1_b", "B_2_a", "B_2_b"))
g <- rbind(g_A, g_B)
n <- 123
set.seed(1)
df <- sample_n(g, n, replace = TRUE)

# Build table
tmp <- c(table(df$x)[1],
         table(df$y)[1],
         table(df$z)[1:2],
         table(df$y)[2],
         table(df$z)[3:4],
         table(df$x)[2],
         table(df$y)[3],
         table(df$z)[5:6],
         table(df$y)[4],
         table(df$z)[7:8])
my_tab <- data.frame("tmp" = names(tmp), "counts" = tmp, "percentages" = round(tmp/n*100, 2))

# flextable operations
ft <- flextable(my_tab)
ft <- set_header_labels(ft, tmp = "")
ft <- align(ft, align = "center")
ft <- align(ft, j = 1, align = "left")
# ft

Now, I would like to indent some names in the first column. For example, to indent A_1 I have tried the following strategies:

compose(ft, i = 2, j = 1, as_paragraph(" A_1"))
compose(ft, i = 2, j = 1, as_paragraph("\t A_1"))
# Or
# colformat_char(ft, i = 2, j = 1, prefix = " ")
# colformat_char(ft, i = 2, j = 1, prefix = "\t")

But they don't work (the result is the same as in Table 1). A "second best" strategy could be the following one (Table 2):

compose(ft, i = 2, j = 1, as_paragraph("- A_1"))
# Or
# colformat_char(ft, i = 2, j = 1, prefix = "- ")

However, I would like a proper indentation.

Finally, I share Table 3, my expected final result, with an indentation in place of each "-".

Waiting for your insights!

Ciao

Answer 1

To indent cells in a flextable you can use padding function:

ft <- padding(ft, i=2, j=1, padding.left=20)