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

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

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

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

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

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

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

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

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

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

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

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

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

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

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 = "user@example.com",
  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

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
)