Dynamic and Streaming Data

Use ChartStreamingDataSource for live or mock dynamic feeds.

Basic setup

@ObservedObject private var stream = ChartStreamingDataSource(
    initialValues: [18, 21, 20, 24, 23, 26],
    windowSize: 6,
    autoScroll: true
)

Bind to a chart

AxisLabels {
    ChartGrid {
        LineChart()
            .chartData(stream)
            .chartYRange(stream.suggestedYRange)
            .chartStyle(
                ChartStyle(
                    backgroundColor: .white,
                    foregroundColor: ColorGradient(.green, .blue)
                )
            )
    }
    .chartGridLines(horizontal: 5, vertical: max(2, stream.values.count))
}
.chartXAxisLabels(stream.xLabels)

Update the stream

stream.append(27)
stream.append(contentsOf: [26, 29, 31])
stream.reset([15, 17, 16], startingIndex: 1)

Source behavior

• windowSize: max visible points (with autoScroll == true)
• autoScroll: trims oldest points after overflow
• xLabels: generated from current visible window indices
• suggestedYRange: dynamic padded range based on current values

Internet-backed flow

Typical pattern:

1. fetch values from API
2. map response to [Double]
3. call stream.append(...) or stream.reset(...)
4. chart updates automatically through ObservableObject