Skip to main content

Documentation Index

Fetch the complete documentation index at: https://docs.darvas.app/llms.txt

Use this file to discover all available pages before exploring further.

​
Overview

These four functions complement plot() with static and per-bar visual layers: 
hline(value, opts?)           // static horizontal reference line
fill(plotA, plotB, opts?)     // shade between two plot handles
bgcolor(color, opts?)         // per-bar background (inside onBar)
barcolor(color, opts?)        // per-bar candle override (inside onBar)

​
hline

Draws a static horizontal line across the entire chart at a fixed price/value. Call at the top level. 
hline(70, { color: "#ef4444FF", linewidth: 1, style: "dashed" });
hline(50, { color: "#6b7280FF", linewidth: 1 });
hline(30, { color: "#22c55eFF", linewidth: 1, style: "dashed" });
Options:
OptionTypeDefaultDescription
colorstringchart default#RRGGBBAA hex
linewidthnumber1Pixels
stylestring"solid""solid", "dotted", "dashed"
titlestring-Tooltip label
Budget: maximum 64 hlines per indicator.

​
fill

Shades the area between two plot series. Both plots must be registered before calling fill. Call at the top level. 
const upper = plot("Upper BB", null, { color: "#22c55eFF" });
const lower = plot("Lower BB", null, { color: "#22c55eFF" });
fill(upper, lower, { color: "#22c55e20" });
Options:
OptionTypeDescription
colorstringFill color (use low alpha, e.g. #22c55e20)
titlestringTooltip label
Budget: maximum 64 fills per indicator.

​
bgcolor

Overrides the chart background color for the current bar. Call inside onBar. 
onBar(() => {
  const rsi = ta.rsi(ctx.close, 14);
  if (na(rsi)) return;

  if (rsi > 70) {
    bgcolor("#ef444420"); // faint red for overbought
  } else if (rsi < 30) {
    bgcolor("#22c55e20"); // faint green for oversold
  }
});
Budget: maximum 1000 bgcolor entries (capped to the last 1000 bars with a non-null color). Passing null clears the color for that bar.

​
barcolor

Overrides the candle/bar color on the main price chart for the current bar. Call inside onBar. 
onBar(() => {
  const isEngulf = ctx.close() > ctx.open(1) && ctx.open() < ctx.close(1);
  barcolor(isEngulf ? "#22c55eFF" : null);
});
Budget: maximum 1000 barcolor entries.

​
Per-bar vs static

PrimitiveWhen to callEffect
hlineTop levelOne horizontal line across entire chart
fillTop levelPersistent band between two plot series
bgcolorInside onBarBackground color for each individual bar
barcolorInside onBarCandle color for each individual bar
bgcolor and barcolor only take effect for bars where they are explicitly called. Bars without a call retain the default chart color.

​
Complete RSI indicator example

// overlay = false
const length = input.int("Length", 14);

const rsiPlot = plot("RSI", null, { color: "#a78bfaFF" });

hline(70, { color: "#ef4444FF", style: "dashed" });
hline(50, { color: "#6b728080", style: "dotted" });
hline(30, { color: "#22c55eFF", style: "dashed" });

onBar(() => {
  const rsi = ta.rsi(ctx.close, length);
  plot("RSI", rsi);
  bgcolor(rsi > 70 ? "#ef444415" : rsi < 30 ? "#22c55e15" : null);
});

Plot basics

plot() - the main time-series drawing primitive.

color.*

Color format and named constants.

API limits

Budget numbers for all drawing primitives.