I have a complex chart that can render variety of graphs in different styles and am working on abstracting these variants into separate view component, one of such examples is
import SwiftUI
import Charts
struct ExerciseChartPlot: View {
// Public Variables
let isLineChart: Bool
let xLabel: String
let yLabel: String
let calendarUnit: Calendar.Component
let date: Date
let value: Double
// Body
var body: some View {
if isLineChart {
LineMark(x: .value(xLabel, date, unit: calendarUnit), y: .value(yLabel, value))
.foregroundStyle(Color._green)
.symbol(.circle)
AreaMark(x: .value(xLabel, date, unit: calendarUnit), y: .value(yLabel, value))
.foregroundStyle(LinearGradient(colors: [._green.opacity(0.2), .clear], startPoint: .top, endPoint: .bottom))
} else {
BarMark(x: .value(xLabel, date, unit: calendarUnit), y: .value(yLabel, value))
.foregroundStyle(Color._green.gradient)
}
}
}
But it results in error of “Static method ‘buildExpression’ requires that ‘some ChartContent’ conform to ‘View'”
I assume this is due to me returning components without wrapping them in Chart. I’d like to keep Chart component on a “higher level” in ui tree and only have these smaller components return chart elements that need to be rendered within it.
Is it possible to achieve this somehow?
What you are trying to create is not a View, but a ChartContent. Conform your struct to ChartContent instead:
struct ExerciseChartPlot: ChartContent {
// Public Variables
...
// Body
var body: some ChartContent {
...
}
}
You can then use this just like any other ChartContent in Chart { ... }.
struct SomeView: View {
var body: some View {
Chart {
ExerciseChartPlot(...)
}
}
}
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