SwiftUICharts Migration Guide

Target release

This guide targets 2.0.0.

2.0.0 is a major breaking release and phases out the old mutable chain API in favor of composable modifier-based configuration.

Version direction

This release moves to a strict SwiftUI-idiomatic modifier API.

Immutable configuration
ViewModifier composition
Environment keys instead of mutable reference state in view structs

Migration checklist

Replace legacy chart types with LineChart, BarChart, PieChart, RingsChart.
Replace old chain methods with chart... modifiers.
Migrate interaction:
- shared value model: chartInteractionValue(_:)
- callback model: chartSelectionHandler(_:)
Validate axis label/range behavior under the unified X-axis alignment model.
Run swift test and build the showcase app to verify rendering parity.

Old -> new mapping

Previous chart data/range chains

Old	New
`.data([Double])`	`.chartData([Double])`
`.data([(Double, Double)])`	`.chartData([(Double, Double)])`
`.rangeX(...)`	`.chartXRange(...)`
`.rangeY(...)`	`.chartYRange(...)`

Grid chains

Old	New
`.setNumberOfHorizontalLines(h)` + `.setNumberOfVerticalLines(v)`	`.chartGridLines(horizontal: h, vertical: v)`
`.setStoreStyle(style)` + `.setColor(color)`	`.chartGridStroke(style: style, color: color)`
`.showBaseLine(show, with: style)`	`.chartGridBaseline(show, style: style)`

Axis chains

Old	New
`.setAxisXLabels([String])`	`.chartXAxisLabels([String])`
`.setAxisXLabels([(Double, String)], range:)`	`.chartXAxisLabels([(Double, String)], range:)`
`.setAxisYLabels([String], position:)`	`.chartYAxisLabels([String], position:)`
`.setAxisYLabels([(Double, String)], range:, position:)`	`.chartYAxisLabels([(Double, String)], range:, position:)`
`.setFont(font)`	`.chartAxisFont(font)`
`.setColor(color)`	`.chartAxisColor(color)`

Line-specific chains

Old	New
`.setLineWidth(width:)`	`.chartLineWidth(...)`
`.setBackground(colorGradient:)`	`.chartLineBackground(...)`
`.showChartMarks(_, with:)`	`.chartLineMarks(_, color:)`
`.setLineStyle(to:)`	`.chartLineStyle(...)`
`.withAnimation(_)`	`.chartLineAnimation(...)`

Interaction wiring

Old	New
`.chartValue(...)` on chart views	`.chartInteractionValue(...)` on any parent container
`@EnvironmentObject ChartValue` requirement	optional environment interaction value
N/A	`.chartSelectionHandler { event in ... }` callback-based selection

Legacy public type replacements

Legacy type	Replacement
`LineChartView`	`LineChart` with modifiers
`BarChartView`	`BarChart` with modifiers
`PieChartView`	`PieChart` with modifiers
`MultiLineChartView`	multiple `LineChart` overlays
`LineView`	`CardView` + `LineChart` + modifiers
`GradientColor`	`ColorGradient`
`GradientColors`	explicit `ColorGradient` values
`Colors`	`ChartColors` + `Color`
`Styles`	explicit `ChartStyle` initialization
`ChartForm`	SwiftUI layout (`frame`, stacks, spacing)
`MultiLineChartData`	multiple `chartData`-configured line layers
`MagnifierRect`	no direct replacement
`TestData`	app/test-local fixtures

Example migration

Before:

swift

AxisLabels {
    ChartGrid {
        LineChart()
            .showChartMarks(true)
            .data([8, 23, 54, 32])
            .rangeY(0...60)
            .chartStyle(ChartStyle(backgroundColor: .white,
                                   foregroundColor: ColorGradient(.orange, .red)))
    }
    .setNumberOfHorizontalLines(5)
    .setNumberOfVerticalLines(4)
}
.setAxisXLabels(["Q1", "Q2", "Q3", "Q4"])

After:

swift

AxisLabels {
    ChartGrid {
        LineChart()
            .chartLineMarks(true)
            .chartData([8, 23, 54, 32])
            .chartYRange(0...60)
            .chartStyle(ChartStyle(backgroundColor: .white,
                                   foregroundColor: ColorGradient(.orange, .red)))
    }
    .chartGridLines(horizontal: 5, vertical: 4)
}
.chartXAxisLabels(["Q1", "Q2", "Q3", "Q4"])

Advanced migration examples

Dynamic streaming data

swift

@ObservedObject private var stream = ChartStreamingDataSource(initialValues: [12, 14, 18, 16],
                                                              windowSize: 8,
                                                              autoScroll: true)

LineChart()
    .chartData(stream)
    .chartYRange(stream.suggestedYRange)

Performance mode for large datasets

swift

LineChart()
    .chartData(largeSeries)
    .chartPerformance(.automatic(threshold: 600, maxPoints: 180, simplifyLineStyle: true))