fmt_flag: Generate flag icons for countries from their country codes

In rstudio/gt: Easily Create Presentation-Ready Display Tables

Generate flag icons for countries from their country codes

Description

While it is fairly straightforward to insert images into body cells (using fmt_image() is one way to it), there is often the need to incorporate specialized types of graphics within a table. One such group of graphics involves iconography representing different countries, and the fmt_flag() function helps with inserting a flag icon (or multiple) in body cells. To make this work seamlessly, the input cells need to contain some reference to a country, and this can be in the form of a 2- or 3-letter ISO 3166-1 country code (e.g., Egypt has the "EG" country code). This function will parse the targeted body cells for those codes (and the countrypops dataset contains all of them) and insert the appropriate flag graphics.

Multiple flags can be included per cell by separating country codes with commas (e.g., "GB,TT"). The sep argument allows for a common separator to be applied between flag icons.

Usage

fmt_flag(
  data,
  columns = everything(),
  rows = everything(),
  height = "1em",
  sep = " ",
  use_title = TRUE,
  locale = NULL
)

Arguments

data	The gt table data object ⁠obj:<gt_tbl>⁠ // required This is the gt table object that is commonly created through use of the gt() function.
columns	Columns to target <column-targeting expression> // default: everything() Can either be a series of column names provided in c(), a vector of column indices, or a select helper function (e.g. starts_with(), ends_with(), contains(), matches(), num_range() and everything()).
rows	Rows to target <row-targeting expression> // default: everything() In conjunction with columns, we can specify which of their rows should undergo formatting. The default everything() results in all rows in columns being formatted. Alternatively, we can supply a vector of row captions within c(), a vector of row indices, or a select helper function (e.g. starts_with(), ends_with(), contains(), matches(), num_range(), and everything()). We can also use expressions to filter down to the rows we need (e.g., ⁠[colname_1] > 100 & [colname_2] < 50⁠).
height	Height of flag ⁠scalar<character>⁠ // default: "1em" The absolute height of the flag icon in the table cell. By default, this is set to "1em".
sep	Separator between flags ⁠scalar<character>⁠ // default: " " In the output of flag icons within a body cell, sep provides the separator between each icon. By default, this is a single space character (" ").
use_title	Display country name on hover ⁠scalar<logical>⁠ // default: TRUE An option to display a tooltip for the country name (in the language according to the locale value, set either here or in gt()) when hovering over the flag icon.
locale	Locale identifier ⁠scalar<character>⁠ // default: NULL (optional) An optional locale identifier that can be used for formatting values according to the locale's rules. Examples include "en" for English (United States) and "fr" for French (France). We can call info_locales() for a useful reference for all of the locales that are supported. A locale ID can be also set in the initial gt() function call (where it would be used automatically by any function with a locale argument) but a locale value provided here will override that global locale.

Value

An object of class gt_tbl.

Compatibility of formatting function with data values

fmt_flag() is compatible with body cells that are of the "character" or "factor" types. Any other types of body cells are ignored during formatting. This is to say that cells of incompatible data types may be targeted, but there will be no attempt to format them.

Compatibility of arguments with the from_column() helper function

from_column() can be used with certain arguments of fmt_flag() to obtain varying parameter values from a specified column within the table. This means that each row could be formatted a little bit differently. These arguments provide support for from_column():

• height

• sep

• use_title

• locale

Please note that for each of the aforementioned arguments, a from_column() call needs to reference a column that has data of the correct type (this is different for each argument). Additional columns for parameter values can be generated with cols_add() (if not already present). Columns that contain parameter data can also be hidden from final display with cols_hide(). Finally, there is no limitation to how many arguments the from_column() helper is applied so long as the arguments belong to this closed set.

Supported regions

The following 242 regions (most of which comprise countries) are supported with names across 574 locales: "AD", "AE", "AF", "AG", "AI", "AL", "AM", "AO", "AR", "AS", "AT", "AU", "AW", "AX", "AZ", "BA", "BB", "BD", "BE", "BF", "BG", "BH", "BI", "BJ", "BL", "BM", "BN", "BO", "BR", "BS", "BT", "BW", "BY", "BZ", "CA", "CC", "CD", "CF", "CG", "CH", "CI", "CK", "CL", "CM", "CN", "CO", "CR", "CU", "CV", "CW", "CY", "CZ", "DE", "DJ", "DK", "DM", "DO", "DZ", "EC", "EE", "EG", "EH", "ER", "ES", "ET", "EU", "FI", "FJ", "FK", "FM", "FO", "FR", "GA", "GB", "GD", "GE", "GF", "GG", "GH", "GI", "GL", "GM", "GN", "GP", "GQ", "GR", "GS", "GT", "GU", "GW", "GY", "HK", "HN", "HR", "HT", "HU", "ID", "IE", "IL", "IM", "IN", "IO", "IQ", "IR", "IS", "IT", "JE", "JM", "JO", "JP", "KE", "KG", "KH", "KI", "KM", "KN", "KP", "KR", "KW", "KY", "KZ", "LA", "LB", "LC", "LI", "LK", "LR", "LS", "LT", "LU", "LV", "LY", "MA", "MC", "MD", "ME", "MF", "MG", "MH", "MK", "ML", "MM", "MN", "MO", "MP", "MQ", "MR", "MS", "MT", "MU", "MV", "MW", "MX", "MY", "MZ", "NA", "NC", "NE", "NF", "NG", "NI", "NL", "NO", "NP", "NR", "NU", "NZ", "OM", "PA", "PE", "PF", "PG", "PH", "PK", "PL", "PM", "PN", "PR", "PS", "PT", "PW", "PY", "QA", "RE", "RO", "RS", "RU", "RW", "SA", "SB", "SC", "SD", "SE", "SG", "SI", "SK", "SL", "SM", "SN", "SO", "SR", "SS", "ST", "SV", "SX", "SY", "SZ", "TC", "TD", "TF", "TG", "TH", "TJ", "TK", "TL", "TM", "TN", "TO", "TR", "TT", "TV", "TW", "TZ", "UA", "UG", "US", "UY", "UZ", "VA", "VC", "VE", "VG", "VI", "VN", "VU", "WF", "WS", "YE", "YT", "ZA", "ZM", and "ZW".

You can view the entire set of supported flag icons as an informative table by calling info_flags().

Examples

Use the countrypops dataset to create a gt table. We will only include a few columns and rows from that table. The country_code_2 column has 2-letter country codes in the format required for fmt_flag() and using that function transforms the codes to circular flag icons.

countrypops |>
  dplyr::filter(year == 2021) |>
  dplyr::filter(grepl("^S", country_name)) |>
  dplyr::arrange(country_name) |>
  dplyr::select(-country_name, -year) |>
  dplyr::slice_head(n = 10) |>
  gt() |>
  fmt_integer() |>
  fmt_flag(columns = country_code_2) |>
  fmt_country(columns = country_code_3) |>
  cols_label(
    country_code_2 = "",
    country_code_3 = "Country",
    population = "Population (2021)"
  )

Using countrypops we can generate a table that provides populations every five years for the Benelux countries ("BE", "NL", and "LU"). This requires some manipulation with dplyr and tidyr before introducing the table to gt. With fmt_flag() we can obtain flag icons in the country_code_2 column. After that, we can merge the flag icons into the stub column, generating row labels that have a combination of icon and text.

countrypops |>
  dplyr::filter(country_code_2 %in% c("BE", "NL", "LU")) |>
  dplyr::filter(year %% 10 == 0) |>
  dplyr::select(country_name, country_code_2, year, population) |>
  tidyr::pivot_wider(names_from = year, values_from = population) |>
  dplyr::slice(1, 3, 2) |>
  gt(rowname_col = "country_name") |>
  tab_header(title = "Populations of the Benelux Countries") |>
  tab_spanner(columns = everything(), label = "Year") |>
  fmt_integer() |>
  fmt_flag(columns = country_code_2) |>
  cols_merge(
    columns = c(country_name, country_code_2),
    pattern = "{2} {1}"
  )

fmt_flag() works well even when there are multiple country codes within the same cell. It can operate on comma-separated codes without issue. When rendered to HTML, hovering over each of the flag icons results in tooltip text showing the name of the country.

countrypops |>
  dplyr::filter(year == 2021, population < 100000) |>
  dplyr::select(country_code_2, population) |>
  dplyr::mutate(population_class = cut(
    population,
    breaks = scales::breaks_pretty(n = 5)(population)
    )
  ) |>
  dplyr::group_by(population_class) |>
  dplyr::summarize(
    countries = paste0(country_code_2, collapse = ",")
  ) |>
  dplyr::arrange(desc(population_class)) |>
  gt() |>
  tab_header(title = "Countries with Small Populations") |>
  fmt_flag(columns = countries) |>
  fmt_bins(
    columns = population_class,
    fmt = ~ fmt_integer(., suffixing = TRUE)
  ) |>
  cols_label(
    population_class = "Population Range",
    countries = "Countries"
  ) |>
  cols_width(population_class ~ px(150))

Function ID

3-24

Function Introduced

v0.9.0 (Mar 31, 2023)

See Also

Other data formatting functions: data_color(), fmt(), fmt_auto(), fmt_bins(), fmt_bytes(), fmt_chem(), fmt_country(), fmt_currency(), fmt_date(), fmt_datetime(), fmt_duration(), fmt_email(), fmt_engineering(), fmt_fraction(), fmt_icon(), fmt_image(), fmt_index(), fmt_integer(), fmt_markdown(), fmt_number(), fmt_partsper(), fmt_passthrough(), fmt_percent(), fmt_roman(), fmt_scientific(), fmt_spelled_num(), fmt_tf(), fmt_time(), fmt_units(), fmt_url(), sub_large_vals(), sub_missing(), sub_small_vals(), sub_values(), sub_zero()

rstudio/gt documentation built on Dec. 2, 2024, 11:05 a.m.