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Documentation Index

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flextable provides a set of convenience functions for changing text appearance. Each targets the i rows and j columns you select inside a given part of the table.

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Bold and italic

bold() and italic() each accept a boolean value and the standard selectors: 
library(flextable)

ft <- flextable(head(iris))
ft <- bold(ft, bold = TRUE, part = "header")   # bold every header cell
ft <- italic(ft, italic = TRUE, part = "header") # italic every header cell
ft
Both default to part = "body" and apply to all rows and columns when i and j are NULL.
Pass bold = FALSE or italic = FALSE to remove formatting previously applied to a selection.

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Font color

color() sets the text color. Accepts any R color name or a hex string: 
ft <- flextable(head(mtcars))
ft <- color(ft, color = "orange", part = "header")
ft <- color(ft, color = "red", i = ~ qsec < 18 & vs < 1)
ft

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Using a color function

When color is a function it is called once per source column and must return a character vector of color values the same length as the number of rows: 
if (require("scales")) {
  scale <- scales::col_numeric(domain = c(-1, 1), palette = "RdBu")
  x <- as.data.frame(cor(iris[-5]))
  x <- cbind(
    data.frame(colname = colnames(x), stringsAsFactors = FALSE),
    x
  )
  ft <- flextable(x)
  ft <- color(ft, j = -1, color = scale, source = -1)
  ft
}
When the colored column j is driven by values from a different (possibly hidden) column, pass that column name to source.

​
Font size

fontsize() sets the font size in points: 
ft <- flextable(head(iris))
ft <- fontsize(ft, size = 14, part = "header")
ft <- fontsize(ft, size = 14, j = 2)   # column 2, body rows
ft <- fontsize(ft, size = 7,  j = 3)   # smaller text in column 3
ft

​
Font family

font() changes the typeface. The fontname string must refer to a font that is installed on the system: 
library(gdtools)

fontname <- "Brush Script MT"

if (font_family_exists(fontname)) {
  ft <- flextable(head(iris))
  ft <- font(ft, fontname = fontname, part = "header")
  ft <- font(ft, fontname = fontname, j = 5)
  ft
}
font() also accepts cs.family, eastasia.family, and hansi.family for complex-script, East-Asian, and HAnsi ranges respectively — these only affect Word and PowerPoint output.
Use gdtools::register_gfont() to load Google Fonts. For HTML output the font is injected automatically into the document.

​
Text highlight

highlight() sets the background shading behind the text (distinct from the cell background set by bg()): 
ft <- flextable(head(mtcars, n = 10))
ft <- highlight(ft, j = "disp", i = ~ disp > 200, color = "yellow")
ft

​
Using a highlight function

my_color_fun <- function(x) {
  out <- rep("yellow", length(x))
  out[x < quantile(x, .75)] <- "pink"
  out[x < quantile(x, .50)] <- "wheat"
  out[x < quantile(x, .25)] <- "gray90"
  out
}

ft <- flextable(head(mtcars, n = 10))
ft <- highlight(ft, j = ~ drat + wt + qsec, color = my_color_fun)
ft

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Formula selectors for conditional formatting

All text formatting functions support formula-based row selection. The formula is evaluated against the body dataset: 
ft <- flextable(head(mtcars, 10))

# Bold rows with high horsepower
ft <- bold(ft, i = ~ hp > 110)

# Color cells in the cyl column red where cyl equals 8
ft <- color(ft, i = ~ cyl == 8, j = "cyl", color = "red")

# Larger text for rows satisfying multiple conditions
ft <- fontsize(ft, i = ~ mpg > 20 & wt < 3, size = 13)
ft
Formula selectors (i = ~ condition) only work with part = "body". Header and footer parts store character representations, so numeric conditions cannot be evaluated on them.

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Using fp_text() for full text control

When you need to set multiple text properties in one call, use style() with an officer::fp_text() object: 
library(officer)

# Define a text style
bold_red <- fp_text(bold = TRUE, color = "red", font.size = 12)

ft <- flextable(head(mtcars))
ft <- style(
  ft,
  i = ~ hp > 100,
  j = "hp",
  pr_t = bold_red
)
ft
fp_text() properties:
PropertyTypeDescription
boldlogicalBold weight
italiclogicalItalic style
underlinedlogicalUnderline
colorcharacterHex or R color name
shading.colorcharacterHighlight color
font.sizenumericSize in points
font.familycharacterFont family name

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Underline and strikethrough

fp_text() supports underlined = TRUE and strike = TRUE. These are not available as standalone convenience functions — use style() with an fp_text() object: 
library(officer)

ft <- flextable(head(iris))
ft <- style(
  ft,
  i = 1:2,
  pr_t = fp_text(underlined = TRUE)
)
ft <- style(
  ft,
  i = 3,
  pr_t = fp_text(strike = TRUE)
)
ft

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Quick reference

FunctionKey argumentDefault part
bold(x, i, j, bold, part)bold = TRUE"body"
italic(x, i, j, italic, part)italic = TRUE"body"
color(x, i, j, color, part)color (required)"body"
fontsize(x, i, j, size, part)size = 11"body"
font(x, i, j, fontname, part)fontname (required)"body"
highlight(x, i, j, color, part)color = "yellow""body"

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