Changes in version 1.2.0 (2026-06-11)                  

LLM tool-calling schema

  - New machine-readable chart specification schema
    (inst/myio-schema.json) describing all chart types, required
    mappings, valid transforms, and function signatures, generated from
    the package's own contracts.
  - Six exported R tools let large language model agents author and
    verify charts against that schema: myio_list_chart_types(),
    myio_chart_schema(), myio_validate_spec(), myio_list_functions(),
    myio_function_signature(), and myio_validate_call(). A Model Context
    Protocol server in the package's source repository exposes the same
    six tools to MCP-compatible clients.
  - New vignette llm-tool-calling demonstrates a
    generate-validate-repair loop.

Uncertainty visualizations

  - New quantile_dots chart type and quantile_dots transform render a
    Wilkinson dot plot of predictive quantiles for communicating
    uncertainty.
  - New fan composite renders a fan chart of nested prediction intervals
    around a central estimate.

Gallery and chart context

  - myIO(title = ...) and setTitle() add a backward-compatible chart
    title surface rendered inside the SVG. Existing charts that omit a
    title are unchanged.
  - Axis titles from setAxisFormat(xLabel = ..., yLabel = ...) now
    render in the chart SVG, and multi-series charts get a compact
    visible legend while preserving the existing action-sheet legend.
  - The gallery now carries chart titles across examples, repairs
    horizontal bars, mean-CI, heatmap margins, gauge thresholds, treemap
    labels, date-based finance examples, and shows themes across a small
    grid of representative charts.

Crosstalk: expanded chart-type coverage

  - setLinked() now links waffle, beeswarm, lollipop, and dumbbell
    layers in addition to the previously supported point, bar,
    groupedBar, histogram, and hexbin. Selection dims non-matching
    elements; filter hides them. Aggregate chart types (boxplot, violin,
    qq, regression, density, ridgeline, survfit, comparison) remain
    outside crosstalk in v1.2.
  - New vignette crosstalk-linking demonstrates linking myIO with
    DT::datatable() and reactable::reactable(), with code listings for
    plotly and leaflet.

bslib and Quarto Dashboards integration

  - myIO() widgets now declare a sizing policy with browser.fill = TRUE
    and are tagged as html-fill-item via htmltools::bindFillRole(), so
    they fill container height inside bslib::card(), Quarto Dashboard
    {.fill} cards, and flexdashboard layouts. Rendering in plain
    RMarkdown and Shiny at the default 400px height is unchanged.
  - Widget resize is now guarded against zero-dimension containers that
    can appear briefly during fill-layout transitions.

Calendar heatmap

  - New calendarHeatmap chart type — GitHub-contributions-style grid of
    daily cells over a single calendar year. Usage: addIoLayer(type =
    "calendarHeatmap", data, mapping = list(date = "day", value = "x")).
    Supports Sunday or Monday week starts via options$weekStart,
    continuous color legend, and linked-cursor sync across two linked
    calendars. Multi-year data is rejected in v1.2; multi-year layouts
    are planned for v1.3. New CSS variables: --chart-calendar-cell-gap,
    --chart-calendar-cell-stroke, --chart-calendar-empty-fill.

Theme gallery

  - 12 named theme presets: setTheme(preset = "midnight"). Available
    presets: midnight, ocean, forest, sunset, monochrome, neon,
    corporate, academic, nature, minimal, retro, warm. Plus light/dark
    via mode parameter.

Linked brushing

  - linkCharts(chart1, chart2, on = "column") enables cross-chart
    selection. Brush in one chart highlights matching rows in linked
    charts. Works in Shiny and static HTML. Aggregation-to-source-row
    key resolution for summary views.

Linked cursor

  - linkCharts() and setLinked() gain a cursor = TRUE argument that
    draws a synchronized vertical crosshair on every linked chart when
    the user hovers any chart in the group. Supports point, bar, line,
    area, groupedBar, hexbin, and histogram layers (donut and treemap
    are excluded — no x-axis to sync on). Off by default; enable
    per-link or retrofit with setLinkedCursor() on a pre-linked widget.
    New --chart-cursor-rule-color/-width/-dasharray CSS variables theme
    the crosshair.

Group-by auto-series

  - Pass a dplyr::group_by() tibble to addIoLayer() and it auto-creates
    one layer per group with colors from the Okabe-Ito palette. Soft
    dplyr dependency.

Survival curves (Kaplan-Meier)

  - addIoLayer(type = "survfit", mapping = list(time = "time", status =
    "status")) computes Kaplan-Meier estimator with Greenwood CI using
    base R only (no survival package dependency). Composite expands to
    step-curve line, CI band, and censored-observation markers. Group
    stratification supported.

Distribution fitting overlay

  - addIoLayer(type = "histogram_fit", mapping = list(value = "x"),
    options = list(family = "normal")) fits normal, lognormal, or
    exponential distributions via MLE. Composite renders histogram +
    fitted density curve + optional parameter annotation.

Layer opacity control

  - setLayerOpacity(label, opacity) sets per-layer opacity (0-1).
    Critical for CI bands overlaying scatter data.

SVG accessibility

  - ARIA roles (graphics-document, graphics-object, graphics-symbol)
    applied to SVG chart structure for screen reader navigation.
  - Keyboard navigation: arrow keys traverse layers and data points,
    with live region announcements (150ms debounce).
  - Hidden data table fallback for screen reader access to raw data
    (capped at 500 rows).
  - Focus ring styling and screen-reader-only utility class.

New chart types

  - lollipop — vertical stem with circle head, supports mean and summary
    transforms. Compatible with categorical x-axis charts.
  - dumbbell — connected dots showing a range between low_y and high_y.
  - waffle — 10x10 grid of colored squares representing proportions.
    Standalone.
  - beeswarm — dodge-positioned points to avoid overlap. Inline dodge
    algorithm.
  - bump — smooth S-curves showing rank/value changes over time with
    grouped lines.
  - radar — spider/radar chart with radial axes and polygon data fill.
  - funnel — narrowing horizontal bars for conversion pipeline data.
  - parallel — parallel coordinates for multivariate exploration. All
    new types support themed colors and standard tooltip formatting.

Small multiples / faceting

  - setFacet(var, ncol, scales) splits charts into a CSS grid of panels,
    one per unique value of the faceting variable. Supports fixed and
    free scale modes, auto-layout with configurable minimum panel width,
    and responsive breakpoints.

Export enhancements

  - setExportOptions() controls which export buttons appear in the
    toolbar (PNG, SVG, clipboard, CSV). New SVG download button and
    clipboard copy (SVG + PNG) via the Clipboard API.
  - CSS custom properties resolved in exported SVGs for correct
    dark-mode colors.

Dark mode / theme system

  - setTheme(mode = "dark") applies a WCAG AA-verified dark palette
    across all chart elements. Also supports "light" and "auto" (detects
    OS preference and Quarto/Bootstrap data-bs-theme).
  - Backward compatible: existing setTheme(bg = "#fff") calls still
    work.
  - New overrides parameter for fine-grained CSS custom property
    control.
  - High-contrast and reduced-motion CSS media query support.

Sparkline mode

  - myIO(sparkline = TRUE) renders a compact, axes-free chart suitable
    for embedding in table cells (reactable, DT, gt). Strips legend,
    axes, reference lines, and all interactions. Default height 20px.
    Supports line, bar, and area layer types.

Bug fixes

  - myio_validate_spec() and the chart specification schema no longer
    reject valid specs for chart types with a single required mapping
    (for example histogram, gauge, and qq). The schema now always
    represents list-typed fields as arrays.

                        Changes in version 1.1.0                        

I/O interaction system

myIO now supports bidirectional data flow — user interactions return
structured data, not just visual feedback.

  - setBrush(): rectangle brush selection on point, bar, histogram,
    hexbin, and grouped bar charts. Selected points available as Shiny
    reactive input or scoped CSV export in static HTML.
  - setAnnotation(): click any data point to attach a label. Annotations
    stored as structured data (source key, coordinates, label, category
    color, timestamp) and exportable as CSV. Supports preset label
    dropdowns and color category pickers.
  - setLinked(): Crosstalk SharedData integration for cross-widget
    linked brushing. Selection dims non-matching points; optional filter
    mode hides them. Supports source, target, or bidirectional modes.
  - setSlider(): parameter sliders below the chart that trigger Shiny
    re-rendering with configurable debounce. Renders disabled with
    tooltip in static HTML.

Bug fixes

  - dragPoints() now correctly emits the dragEnd event to Shiny
    (input$myIO-{id}-dragEnd), which was previously registered but never
    fired.

                        Changes in version 1.0.0                        

Statistical transforms

  - New composable transform pipeline: type + transform = layer.
    Transforms compute statistics in R; renderers display them in D3.js.
  - Transforms: lm, loess, polynomial, ci, smooth, mean, mean_ci,
    residuals, summary, pairwise_test, qq.
  - Composite chart expansion: complex charts decompose into primitive
    layers.

Chart types (20)

  - Basic: line, point, bar, area, groupedBar.
  - Statistical: histogram, hexbin, regression, qq.
  - Distribution: boxplot, violin, ridgeline, comparison.
  - Financial: candlestick, waterfall, heatmap.
  - Standalone: donut, gauge, treemap, sankey.

Composites

  - boxplot: expands into IQR box + whisker caps + median + outliers.
  - violin: expands into density area + IQR box + median point.
  - ridgeline: density curves stacked vertically by group.
  - regression: scatter + trend line + CI band + R-squared annotation.
  - qq: Q-Q scatter + reference line + confidence envelope.
  - comparison: boxplots + pairwise significance brackets.

Interactions

  - Tooltips with automatic formatting via setToolTipOptions().
  - Drag interaction via dragPoints().
  - CSV, SVG, and PNG export buttons.
  - Reference lines via setReferenceLines().
  - Y-variable toggle via setToggle().

Infrastructure

  - Responsive sizing that adapts to container dimensions.
  - Shiny integration with myIOOutput() and renderMyIO().
  - Pipe-friendly API using native |>.
  - Theming via CSS custom properties with setTheme().
  - Okabe-Ito colorblind-safe default palette.