Package 'a11yShiny'

Accessible action button

Description

A wrapper for shiny::actionButton() with ARIA attributes according to BITV 2.0, enforced visible label or aria-label, and custom CSS class.

Usage

a11y_actionButton(
  inputId,
  label = NULL,
  icon = NULL,
  aria_label = NULL,
  aria_controls = NULL,
  ...
)

Arguments

inputId	Button ID
label	(optional) Visible label
icon	(optional) Icon, e.g. shiny::icon("check")
aria_label	(optional, but required if label is missing or empty) ARIA label for buttons without text
aria_controls	(optional) ARIA controls attribute
...	Additional arguments for shiny::actionButton()

Value

HTML ⁠<button>⁠ tag with appropriate ARIA attributes

Examples

# Button with a visible label
a11y_actionButton("btn1", label = "Submit")

# Icon-only button (aria_label required)
a11y_actionButton("btn2",
  icon = shiny::icon("search"),
  aria_label = "Search"
)

# Button with aria-controls linking to another element
a11y_actionButton("btn3",
  label = "Toggle",
  aria_controls = "panel1"
)

# Button with visible label, icon, and additional aria-label
a11y_actionButton("refresh",
  label = "Refresh",
  icon = shiny::icon("refresh"),
  aria_label = "Click to refresh data"
)

---

Accessible column

Description

A wrapper for shiny::column() with optional ARIA attributes according to BITV 2.0 and custom CSS class. Ensures responsive layout by validating that columns have appropriate widths.

Usage

a11y_column(width, ..., offset = NULL, id = NULL, aria_label = NULL)

Arguments

width	Column width (as in shiny::column(): 1–12)
...	Content for column
offset	(optional) Column offset (as in shiny::column(), 1–12)
id	(optional) Column ID
aria_label	(optional) aria-label for the column/region

Value

HTML ⁠<div>⁠ tag with classes for grid and a11y

Examples

# Simple column
a11y_column(6, htmltools::p("Half width content"))

# Column with offset and aria-label
a11y_column(4,
  offset = 2,
  aria_label = "Sidebar",
  htmltools::p("Offset column")
)

# Column with a descriptive aria-label for a form section
a11y_column(4,
  aria_label = "Histogram settings",
  htmltools::p("Configuration controls go here")
)

---

Accessible date input

Description

A wrapper for shiny::dateInput() with ARIA attributes according to BITV 2.0, enforced visible label, optional heading annotation, custom CSS class, and sr-only description support.

Usage

a11y_dateInput(
  inputId,
  label,
  value = NULL,
  min = NULL,
  max = NULL,
  format = "yyyy-mm-dd",
  startview = "month",
  weekstart = 1,
  language = "en",
  width = NULL,
  ...,
  describedby = NULL,
  describedby_text = NULL,
  heading_level = NULL,
  aria_controls = NULL
)

Arguments

inputId	Input ID
label	Visible label (required)
value	Initial date value (Date or string, optional)
min	Minimum date (optional)
max	Maximum date (optional)
format	Date format (as in shiny::dateInput(), default: "yyyy-mm-dd")
startview	Initial view ("month", "year", "decade"; default: "month")
weekstart	First day of the week (1 = Monday, default: 1)
language	Language for the datepicker (default: "en")
width	Control width (optional)
...	Additional arguments for shiny::dateInput()
describedby	ID of an element for aria-describedby (optional)
describedby_text	Creates an sr-only ⁠<div>⁠ that serves as a description and is linked via aria-describedby. If describedby is set, its ID is used, otherwise an ID is generated (⁠<inputId>-desc⁠). (optional)
heading_level	1–6, marks the visible ⁠<label>⁠ as a heading via role="heading" and aria-level (optional)
aria_controls	(optional) ARIA controls attribute

Value

HTML tag of the input component (possibly with sr-only description)

Examples

# Basic date input
a11y_dateInput("start", "Start date")

# With German datepicker, custom format and description
a11y_dateInput("birthday", "Date of birth",
  format = "dd.mm.yyyy",
  language = "de",
  describedby_text = "Enter your date of birth"
)

# Date input with heading-level annotation
a11y_dateInput("mydate", "Select date:",
  language = "de",
  heading_level = 2
)

---

Accessible fluid page

Description

A wrapper for shiny::fluidPage() with required title/lang, one main landmark, optional header/nav/aside/footer, skip link, and flexible layout CSS.

Usage

a11y_fluidPage(
  ...,
  title,
  lang = NULL,
  main = NULL,
  main_id = "main-content",
  header = NULL,
  nav = NULL,
  aside = NULL,
  footer = NULL
)

Arguments

...	Content to go inside ⁠<main>⁠ when main is NULL, or extra children to append to main
title	Page title (required)
lang	Language code (required)
main	(optional) ⁠<main>⁠ tag (tags$main(...)); if provided, it is normalized (id/class ensured)
main_id	(optional) ID to assign if the main has no id yet (default "main-content")
header	(optional) Header content or tags$header(...)
nav	(optional) Nav content or tags$nav(...)
aside	(optional) Aside content or tags$aside(...)
footer	(optional) Footer content or tags$footer(...)

Details

• Enforces title and lang

• Ensures exactly one ⁠<main id="main-content">⁠

• Attaches the CSS dependency (use_a11y) for flexible layout (.a11y-flow)

• Allows optional header/nav/aside/footer blocks

Value

A Shiny UI tag (page)

Examples

# Minimal accessible page
a11y_fluidPage(
  title = "My App",
  lang  = "en",
  htmltools::h1("Welcome")
)

# Page with header and footer
a11y_fluidPage(
  title  = "Dashboard",
  lang   = "de",
  header = htmltools::tags$header(htmltools::h1("Dashboard")),
  footer = htmltools::tags$footer("Footer content"),
  htmltools::p("Main content goes here")
)

---

Accessible fluid row

Description

A wrapper for shiny::fluidRow() with optional section landmarks, ARIA attributes according to BITV 2.0, and custom CSS class. Ensures responsive layout by validating that all columns are a11y_columns and their widths sum to 12.

Usage

a11y_fluidRow(..., id = NULL, aria_label = NULL)

Arguments

...	Content to place into the row (columns, tags)
id	(optional) Row ID
aria_label	(optional) aria-label for the row (helpful for sections)

Value

HTML ⁠<section>⁠ tag (row)

Examples

# A row with two columns (widths must sum to 12)
a11y_fluidRow(
  a11y_column(6, htmltools::p("Left")),
  a11y_column(6, htmltools::p("Right"))
)

# Labeled section row
a11y_fluidRow(
  a11y_column(12, htmltools::p("Full width")),
  aria_label = "Results section"
)

---

Accessible bar chart

Description

A minimal wrapper for a simple bar chart with accessibility features using ggplot2::ggplot2. Provides a high-contrast color palette, black bar outlines, and a minimal theme by default.

Usage

a11y_ggplot2_bar(
  data,
  x,
  y,
  accessible_colors = NULL,
  border_color = "#000000",
  bar_width = 0.9,
  legend_title = NULL,
  ...
)

Arguments

data	Data frame
x	Column name for categories (unquoted)
y	Column name for bar heights (unquoted)
accessible_colors	(optional) Character vector of colors for the palette
border_color	(optional) Color for bar outlines (default: "#000000")
bar_width	(optional) Bar width (default: 0.9)
legend_title	(optional) Title for the legend (default: NULL)
...	Additional arguments passed to ggplot2::labs() (e.g. title, axis labels)

Value

A ggplot2::ggplot() object

Examples

df <- data.frame(
  category = c("Alpha", "Beta", "Gamma"),
  count    = c(23, 17, 31)
)
a11y_ggplot2_bar(
  data = df, x = category, y = count,
  title = "Counts by Category"
)

---

Accessible line chart

Description

A minimal wrapper for a multi-line chart with accessibility features using ggplot2::ggplot2. Provides a high-contrast color palette, distinct marker shapes, and a minimal theme by default.

Usage

a11y_ggplot2_line(
  data,
  x,
  y,
  group = NULL,
  accessible_colors = NULL,
  marker_shapes = NULL,
  line_width = 1,
  marker_size = 2,
  legend_title = NULL,
  ...
)

Arguments

data	Data frame
x	Column name for the x-axis (unquoted)
y	Column name for the y-axis (unquoted)
group	(optional) Column name for grouping lines (unquoted)
accessible_colors	(optional) Character vector of colors for the palette
marker_shapes	(optional) Numeric vector of point shapes, e.g. c(16, 17, 15, 3, 7, 4, 10)
line_width	(optional) Line width (default: 1)
marker_size	(optional) Point size (default: 2)
legend_title	(optional) Title for the legend
...	Additional arguments passed to ggplot2::labs()

Value

A ggplot2::ggplot() object

Examples

# Simple line chart (no grouping)
df <- data.frame(year = 2020:2024, value = c(10, 14, 13, 17, 20))
a11y_ggplot2_line(
  data = df, x = year, y = value,
  title = "Trend"
)

# Grouped line chart
df2 <- data.frame(
  year  = rep(2020:2024, 2),
  value = c(10, 14, 13, 17, 20, 8, 9, 11, 12, 15),
  grp   = rep(c("A", "B"), each = 5)
)
a11y_ggplot2_line(
  data = df2, x = year, y = value,
  group = grp, title = "Trend by Group"
)

# With legend title and additional ggplot2 layers
p <- a11y_ggplot2_line(
  data = df2, x = year, y = value, group = grp,
  legend_title = "Group",
  title = "Trend by Group"
)
p + ggplot2::geom_hline(yintercept = 12, linetype = "dashed") +
  ggplot2::labs(
    x = "Year", y = "Value",
    subtitle = "With custom axis labels"
  )

---

Accessible high-contrast toggle button

Description

A toggle button that switches high-contrast mode by adding/removing the CSS class .high-contrast on the ⁠<body>⁠ element, with ARIA attributes according to BITV 2.0.

Usage

a11y_highContrastButton(
  inputId = "toggle_contrast",
  label = "Contrast Mode",
  icon = shiny::icon("adjust"),
  aria_label = "Toggle high-contrast mode on or off",
  ...
)

Arguments

inputId	Button ID (default: "toggle_contrast")
label	Visible label (optional, e.g. "High Contrast")
icon	Optional icon, e.g. shiny::icon("adjust")
aria_label	ARIA label (required if label is missing/empty)
...	Additional arguments for a11y_actionButton()

Details

• Uses a11y_actionButton() internally (visible label or aria-label).

• Sets aria-pressed and toggles this state via JS.

• Adds the class .a11y-high-contrast-toggle to which the JS is attached.

Value

HTML tag of the button component

Examples

# Default high-contrast toggle button
a11y_highContrastButton()

# Custom label in English
a11y_highContrastButton(
  label      = "High Contrast",
  aria_label = "Toggle high-contrast mode"
)

# Icon-only toggle (no visible label)
a11y_highContrastButton(
  label      = NULL,
  icon       = shiny::icon("adjust"),
  aria_label = "Toggle high-contrast mode"
)

---

Accessible numeric input

Description

A wrapper for shiny::numericInput() with ARIA attributes according to BITV 2.0, enforced visible label, optional heading annotation, custom CSS class, and sr-only description support.

Usage

a11y_numericInput(
  inputId,
  label,
  value,
  min = NA,
  max = NA,
  step = NA,
  ...,
  describedby = NULL,
  describedby_text = NULL,
  heading_level = NULL,
  aria_controls = NULL
)

Arguments

inputId	Input ID
label	Visible label (required)
value	Initial numeric value
min	Minimum value (optional; NA for none)
max	Maximum value (optional; NA for none)
step	Step size (optional; NA for none)
...	Additional arguments for shiny::numericInput()
describedby	ID of help text for aria-describedby (optional)
describedby_text	Creates an sr-only ⁠<div>⁠ that serves as a description and is linked via aria-describedby. If describedby is set, its ID is used, otherwise an ID is generated (⁠<inputId>-desc⁠). (optional)
heading_level	1–6, marks the visible ⁠<label>⁠ as a heading via role="heading" and aria-level (optional)
aria_controls	(optional) ARIA controls attribute

Value

HTML tag of the input component

Examples

# Basic numeric input
a11y_numericInput("age", "Age", value = 30, min = 0, max = 120)

# With heading-level annotation and description
a11y_numericInput("score", "Score",
  value = 0,
  min = 0, max = 100,
  heading_level = 3,
  describedby_text = "Enter a value between 0 and 100"
)

# Linking to an existing help-text element by its ID
a11y_numericInput("seed", "Seed",
  value = 123,
  describedby = "seed_help"
)

---

Accessible radio buttons

Description

A wrapper for shiny::radioButtons() with ARIA attributes according to BITV 2.0, enforced visible label, optional heading annotation, custom CSS class, and sr-only description support.

Usage

a11y_radioButtons(
  inputId,
  label,
  choices,
  selected = NULL,
  inline = FALSE,
  ...,
  describedby = NULL,
  describedby_text = NULL,
  heading_level = NULL,
  aria_controls = NULL
)

Arguments

inputId	Input ID
label	Visible label (required)
choices	Choices (as in shiny::radioButtons())
selected	Preselected value (optional)
inline	Display inline (logical, default: FALSE)
...	Additional arguments for shiny::radioButtons()
describedby	ID of an element for aria-describedby (optional)
describedby_text	Creates an sr-only ⁠<div>⁠ that serves as a description and is linked via aria-describedby. If describedby is set, its ID is used, otherwise an ID is generated (⁠<inputId>-desc⁠). (optional)
heading_level	1–6, marks the visible ⁠<label>⁠ as a heading via role="heading" and aria-level (optional)
aria_controls	(optional) ARIA controls attribute

Value

HTML tag of the input component (possibly with sr-only description)

Examples

# Basic radio buttons
a11y_radioButtons("format", "Output format",
  choices = c("CSV", "Excel", "JSON")
)

# Inline layout with heading annotation
a11y_radioButtons("yesno", "Agree?",
  choices = c("Yes", "No"),
  inline = TRUE,
  heading_level = 4
)

# With named choices and a screen-reader description
a11y_radioButtons("radio_choice", "Pick one",
  choices = list(
    "Option 1" = 1,
    "Option 2" = 2,
    "Option 3" = 3
  ),
  selected = 1,
  describedby_text = "Select one of the three options"
)

---

Accessible DataTable renderer

Description

A wrapper for DT::renderDataTable() that enables keyboard navigation (KeyTable extension) by default and provides built-in German/English translations.

Usage

a11y_renderDataTable(expr, lang = NULL, dt_language = NULL, ...)

Arguments

expr	Table expression
lang	Language code ("de" or "en"), or NULL if dt_language is set in expr()
dt_language	(optional) DT language list (see DT docs); required when using a language other than "de"/"en"
...	Other DT::renderDataTable() arguments

Value

A Shiny render function

Examples

# Inside a Shiny server function
if (interactive()) {
  library(shiny)
  server <- function(input, output, session) {
    output$table <- a11y_renderDataTable(
      expr = mtcars[, 1:5],
      lang = "en"
    )
  }
}

# German-language table with Buttons extension and accessible export options
if (interactive()) {
  library(shiny)
  server <- function(input, output, session) {
    output$table_de <- a11y_renderDataTable(
      expr = head(iris[, 1:4], 10),
      lang = "de",
      selection = "none",
      extensions = c("Buttons"),
      options = list(
        pageLength = 5,
        dom = "Bfrtip",
        buttons = c("excel", "csv")
      )
    )
  }
}

---

Accessible select input

Description

A wrapper for shiny::selectInput() with ARIA attributes according to BITV 2.0, enforced visible label, optional heading annotation, custom CSS class, and sr-only description support.

Usage

a11y_selectInput(
  inputId,
  label,
  choices,
  selected = NULL,
  multiple = FALSE,
  ...,
  describedby = NULL,
  describedby_text = NULL,
  heading_level = NULL,
  aria_controls = NULL
)

Arguments

inputId	Input ID
label	Visible label (required)
choices	Choice list (as in shiny::selectInput())
selected	Preselection (optional)
multiple	Multiple selection (default: FALSE)
...	Additional arguments for shiny::selectInput()
describedby	ID of an element for aria-describedby (optional)
describedby_text	Creates an sr-only ⁠<div>⁠ that serves as a description and is linked via aria-describedby. If describedby is set, its ID is used, otherwise an ID is generated (⁠<inputId>-desc⁠). (optional)
heading_level	1–6, marks the visible ⁠<label>⁠ as a heading via role="heading" and aria-level (optional)
aria_controls	(optional) ARIA controls attribute

Value

HTML tag of the input component (possibly with sr-only description)

Examples

# Basic select input
a11y_selectInput("colour", "Colour",
  choices = c("Red", "Green", "Blue")
)

# With a screen-reader-only description
a11y_selectInput("size", "Size",
  choices = c("S", "M", "L"),
  describedby_text = "Choose a t-shirt size"
)

# Label promoted to a heading (useful for sectioned forms)
a11y_selectInput("n_breaks", "Number of bins",
  choices = c(10, 20, 35, 50),
  selected = 20,
  heading_level = 3
)

# Linking to an existing description element via its ID
htmltools::tags$p(id = "n_breaks_help", "Choose how many bins to display")
a11y_selectInput("n_breaks2", "Number of bins",
  choices = c(10, 20, 35, 50),
  describedby = "n_breaks_help"
)

---

Accessible text input with action button

Description

A composite component combining a11y_textInput() and a11y_actionButton() with BITV 2.0-conform ARIA attributes. The text input enforces a visible label; the button enforces either a visible label or an aria-label. By default the button gets aria-controls pointing to the text input.

Usage

a11y_textButtonGroup(
  textId,
  buttonId,
  label,
  value = "",
  placeholder = NULL,
  button_label = NULL,
  button_icon = NULL,
  button_aria_label = NULL,
  controls = NULL,
  layout = c("inline", "stack"),
  text_describedby = NULL,
  text_describedby_text = NULL,
  text_heading_level = NULL
)

Arguments

textId	ID for the inner text input (required)
buttonId	ID for the inner action button (required)
label	Visible label for the text input (required)
value	Initial value for the text input (default: "")
placeholder	Placeholder for the text input (optional)
button_label	Visible label for the button (optional; if omitted/empty, button_aria_label is required)
button_icon	Icon for the button (e.g. shiny::icon("search"), optional)
button_aria_label	ARIA label for the button (required if button_label is missing or empty)
controls	ID referenced by aria-controls on the button. If NULL, defaults to textId.
layout	"inline" (default) or "stack". Inline places text and button in one row; stack places them under each other.
text_describedby	ID for aria-describedby of the text input (optional)
text_describedby_text	Creates an sr-only ⁠<div>⁠ as description for the text input. If text_describedby is set, that ID is used, otherwise ⁠<textId>-desc⁠ (optional)
text_heading_level	1–6, marks the visible ⁠<label>⁠ of the text input as heading via role="heading" and aria-level (optional)

Value

HTML tag containing the labeled text input and button

Examples

# Search box with icon-only button
a11y_textButtonGroup(
    textId = "search_text",
    buttonId = "search_btn",
    label = "Search",
    placeholder = "Enter a keyword",
    button_icon = shiny::icon("search"),
    button_aria_label = "Run search"
)

# Stacked layout with visible button label
a11y_textButtonGroup(
    textId = "comment_text",
    buttonId = "comment_btn",
    label = "Comment",
    button_label = "Send",
    layout = "stack"
)

# With screen-reader description and heading-level on the label
a11y_textButtonGroup(
    textId = "query_text",
    buttonId = "query_btn",
    label = "Search query",
    placeholder = "Enter a keyword",
    button_icon = shiny::icon("search"),
    button_aria_label = "Run search",
    text_describedby_text = "Type a keyword and press the search button",
    text_heading_level = 3
)

---

Accessible text input

Description

A wrapper for shiny::textInput() with ARIA attributes according to BITV 2.0, enforced visible label, optional heading annotation, custom CSS class, and sr-only description support.

Usage

a11y_textInput(
  inputId,
  label,
  value = "",
  width = NULL,
  placeholder = NULL,
  ...,
  describedby = NULL,
  describedby_text = NULL,
  heading_level = NULL,
  aria_controls = NULL
)

Arguments

inputId	Input ID
label	Visible label (required)
value	Initial text value (default: "")
width	Control width (optional)
placeholder	Placeholder text (optional)
...	Additional arguments for shiny::textInput()
describedby	ID of an element for aria-describedby (optional)
describedby_text	Creates an sr-only ⁠<div>⁠ that serves as a description and is linked via aria-describedby. If describedby is set, its ID is used, otherwise an ID is generated (⁠<inputId>-desc⁠). (optional)
heading_level	1–6, marks the visible ⁠<label>⁠ as a heading via role="heading" and aria-level (optional)
aria_controls	(optional) ARIA controls attribute

Value

HTML tag of the input component (possibly with sr-only description)

Examples

# Basic text input
a11y_textInput("name", "Full name")

# With placeholder and screen-reader description
a11y_textInput("email", "E-mail address",
  placeholder = "[email protected]",
  describedby_text = "We will never share your e-mail"
)

# With heading-level annotation (for sectioned forms)
a11y_textInput("company", "Company name",
  heading_level = 3
)

# Linking to an existing description element via its ID
a11y_textInput("query", "Search query",
  describedby = "query_help"
)

---

Accessible group of text inputs

Description

A wrapper for a group of related text input elements inside a ⁠<fieldset>⁠/⁠<legend>⁠ with ARIA attributes according to BITV 2.0. Intended for combined form elements that belong together (e.g. address fields, date parts, etc.).

Usage

a11y_textInputsGroup(
  groupId,
  legend,
  inputs,
  describedby = NULL,
  describedby_text = NULL,
  legend_heading_level = NULL
)

Arguments

groupId	ID for the fieldset/group (used as id of ⁠<fieldset>⁠)
legend	Visible group label (used as ⁠<legend>⁠, required)
inputs	A list of input specifications. Each element must be a list with: inputId ID of the text input (required) label Visible label for this text field (optional) value Initial value (optional, default: "") placeholder Placeholder text (optional) width Width for this field (optional, as in shiny::textInput()) aria_label Accessible name via aria-label (optional – required if no visible label and no title) title Title attribute for additional explanation or as accessible name if no visible label (optional)
describedby	ID of an element used for aria-describedby on the group (optional)
describedby_text	Creates an sr-only ⁠<div>⁠ that serves as a description for the group and is linked via aria-describedby. If describedby is set, its ID is used, otherwise an ID is generated (⁠<groupId>-desc⁠). (optional)
legend_heading_level	1–6, marks the visible ⁠<legend>⁠ as a heading via role="heading" and aria-level (optional)

Details

• The group gets a visible legend (required).

• Each inner text input has its own ID.

• For each inner input you must provide at least one of: a visible label, an aria_label, or a title attribute.

• The fieldset is marked as role="group" and is linked to the legend via aria-labelledby.

Value

HTML tag of the fieldset containing multiple text inputs (possibly with an sr-only group description)

Examples

# Address field group
a11y_textInputsGroup(
    groupId = "address",
    legend = "Address",
    inputs = list(
        list(inputId = "street", label = "Street"),
        list(inputId = "city", label = "City"),
        list(inputId = "zip", label = "ZIP code")
    )
)

# With group description and legend promoted to heading level
a11y_textInputsGroup(
    groupId = "address_full",
    legend = "Postal address",
    inputs = list(
        list(inputId = "street2", label = "Street and number"),
        list(inputId = "zip2", label = "ZIP code", width = "120px"),
        list(inputId = "city2", label = "City"),
        list(inputId = "country2", label = "Country")
    ),
    describedby_text = "Please enter your full postal address.",
    legend_heading_level = 3
)

---