Chart

Charming::Components::Chart plots a numeric series into a width × height box of character cells. The default kind: :line draws a connected line on a Charming::UI::BrailleCanvas, which gives you 2×4 subpixels per cell; kind: :bar draws vertical bars from eighth-block glyphs. It is a static renderable — pure text with no keyboard handling — so it works on every terminal and composes with row/column/box like any other view output.

Line (braille)                  Bar (blocks)
⠀⠀⠀⠀⢀⠔⠉⠑⢄⠀⠀⠀⠀⠀⠀⠀           ▂█
⠀⠀⡠⠊⠀⠀⠀⠀⠀⠑⢄⠀⠀⠀⠀⠀          ▅██▃
⡠⠊⠀⠀⠀⠀⠀⠀⠀⠀⠀⠑⢄⡀⠀⠀        ▁█████▆▂

Quick start

class ShowView < Charming::View
  def render
    render_component(Charming::Components::Chart.new(
      series: assigns.fetch(:series),
      width: 32,
      height: 4,
      style: theme.info
    ))
  end
end

Pass kind: :bar for bars:

render_component(Charming::Components::Chart.new(
  series: series, width: 16, height: 4, kind: :bar, style: theme.warn
))

Options

Option	Default	What it does
series:	required	The numeric data to plot.
width:	required	Chart width in character cells.
height:	required	Chart height in character cells.
kind:	:line	:line for a braille-canvas line plot, :bar for eighth-block bars.
style:	nil	A Charming::UI::Style used to paint the whole chart (e.g. theme.info).
theme:	nil	Forwarded to the view layer.

How the two kinds scale

• Line spreads the series across width * 2 × height * 4 braille subpixels, scaled between the series’ min and max, and connects consecutive points with line segments.
• Bar resamples the series to exactly width columns (nearest-neighbour), then scales bars from a baseline of min(0, series minimum) — so an all-positive series grows from zero, and a series with negatives grows from its minimum.

An empty series (or a non-positive box) renders as an empty string.

Tips

• Values normalize to the box: the tallest point always touches the top and the range stretches to fill height. Two charts side by side are not on a shared scale unless you pad their series to the same min/max yourself.
• In bar mode, a series longer than width is resampled down — one column per cell — so fine detail between neighbouring values can disappear. Widen the chart or pre-aggregate if that matters.
• A flat series (all values equal) renders at the baseline rather than mid-box.