Accessibility

dashboardr includes built-in accessibility enhancements targeting WCAG 2.1 AA compliance. These features are activated with enable_accessibility().

library(dashboardr)

Enabling Accessibility

Add enable_accessibility() to include the accessibility CSS and JavaScript:

page <- create_page("Analysis") %>%
  add_viz(
    type = "bar",
    x_var = "category",
    title = "Results",
    alt_text = "Bar chart showing category counts"
  )

enable_accessibility() is called automatically during page generation.

Features

A “Skip to main content” link appears at the top of the page when a keyboard user presses Tab. This allows users to bypass navigation and jump directly to the dashboard content.

Focus Indicators

All interactive elements (tabs, inputs, buttons, links) receive visible focus outlines when navigated via keyboard. The default focus style uses a 3px blue outline that meets WCAG contrast requirements.

When a modal dialog is open, Tab and Shift+Tab cycle focus only within the modal’s focusable elements. When the modal closes, focus returns to the element that triggered it.

Dashboard tabs support full keyboard navigation:

Arrow Left/Right: Move between tabs
Home: Jump to the first tab
End: Jump to the last tab
Enter/Space: Activate the focused tab

ARIA Live Region

Filter changes are announced to screen readers via an ARIA live region. When a user changes a filter input, the announcement includes the filter name and selected values.

Reduced Motion

When the user’s operating system has “reduce motion” enabled (prefers-reduced-motion: reduce), all CSS transitions and animations are disabled.

Alt Text for Visualizations

Add descriptive alt text to charts using the alt_text parameter on any add_viz() call:

page <- create_page("Demographics") %>%
  add_viz(
    type = "bar",
    x_var = "age_group",
    title = "Age Distribution",
    alt_text = "Bar chart showing the distribution of respondents across age groups, with 25-34 being the largest group"
  ) %>%
  add_viz(
    type = "stackedbar",
    x_var = "region",
    stack_var = "gender",
    title = "Gender by Region",
    alt_text = "Stacked bar chart comparing gender proportions across four regions"
  )

ARIA Labels on Value Boxes and Metrics

Value boxes and metrics support aria_label for screen reader descriptions:

page <- create_page("Summary") %>%
  add_value_box(
    title = "Total Responses",
    value = "1,234",
    icon = "mdi:account-group",
    aria_label = "Total survey responses: 1,234"
  ) %>%
  add_metric(
    title = "Response Rate",
    value = "78%",
    aria_label = "Survey response rate: 78 percent"
  )

Example Dashboard

data <- data.frame(
  category = rep(c("A", "B", "C", "D"), each = 25),
  region = rep(c("North", "South"), 50),
  value = round(rnorm(100, 50, 10))
)

dashboard <- create_dashboard(
  title = "Accessible Dashboard",
  data = data
) %>%
  add_page(
    create_page("Overview") %>%
      add_value_box(
        title = "Records",
        value = "100",
        aria_label = "Total records: 100"
      ) %>%
      add_viz(
        type = "bar",
        x_var = "category",
        title = "Categories",
        alt_text = "Bar chart showing counts for categories A through D"
      ) %>%
      add_viz(
        type = "stackedbar",
        x_var = "category",
        stack_var = "region",
        title = "By Region",
        alt_text = "Stacked bar chart showing regional breakdown per category"
      )
  )

WCAG 2.1 AA Notes

The accessibility features target WCAG 2.1 Level AA. Key areas covered:

1.3.1 Info and Relationships: ARIA roles and labels on interactive elements
2.1.1 Keyboard: All functionality available via keyboard
2.4.1 Bypass Blocks: Skip-to-content link
2.4.3 Focus Order: Logical tab order with focus trapping in modals
2.4.7 Focus Visible: Visible focus indicators on all interactive elements
2.3.3 Animation from Interactions: Reduced motion support
4.1.3 Status Messages: ARIA live region for filter announcements

Chart accessibility depends on the rendering backend. Highcharts includes built-in screen reader support and keyboard navigation for chart data points.