Custom Types with Builder API

Demonstrates how to use the Builder Api with Custom Types using SciChart.js, High Performance JavaScript Charts

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drawExample.ts

index.html

vanilla.ts

theme.ts

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1import {
2    SciChartSurface,
3    build2DChart,
4    buildSeries,
5    registerType,
6    registerAllTypes,
7    ESeriesType,
8    EAxisType,
9    ELineDrawMode,
10    XyDataSeries,
11    EAnimationType,
12    EAxisAlignment,
13    EPaletteProviderType,
14    EFillPaletteMode,
15    EStrokePaletteMode,
16    IFillPaletteProvider,
17    IStrokePaletteProvider,
18    IRenderableSeries,
19    EBaseType,
20    parseColorToUIntArgb,
21    NumberRange,
22    EAnnotationType,
23    ECoordinateMode,
24    EHorizontalAnchorPoint,
25    EVerticalAnchorPoint,
26} from "scichart";
27import { appTheme } from "../../theme";
28
29// The Builder API is lean by default in v6. This chart is defined with type-strings only,
30// so register the built-in types before building it
31registerAllTypes();
32
33// Define a custom PaletteProvider
34export class ExampleMountainPaletteProvider implements IStrokePaletteProvider, IFillPaletteProvider {
35    public static Name = "ExampleMountain";
36    public readonly strokePaletteMode = EStrokePaletteMode.SOLID;
37    public readonly fillPaletteMode = EFillPaletteMode.SOLID;
38    private readonly palettedStroke: number;
39    private readonly palettedFill: number;
40    private readonly options: { stroke: string; fill: string };
41
42    constructor(options: { stroke: string; fill: string }) {
43        this.options = options;
44        this.palettedStroke = parseColorToUIntArgb(options.stroke);
45        this.palettedFill = parseColorToUIntArgb(options.fill);
46    }
47
48    // tslint:disable-next-line:no-empty
49    public onAttached(parentSeries: IRenderableSeries): void {}
50
51    // tslint:disable-next-line:no-empty
52    public onDetached(): void {}
53
54    public overrideFillArgb(xValue: number, yValue: number, index: number): number {
55        if (yValue > 0.5 && yValue < 0.75) {
56            return this.palettedFill;
57        } else {
58            return undefined;
59        }
60    }
61
62    public overrideStrokeArgb(xValue: number, yValue: number, index: number): number {
63        if (yValue > 0.5 && yValue < 0.75) {
64            return this.palettedStroke;
65        } else {
66            return undefined;
67        }
68    }
69
70    // Add a toJSON method so this can be serialized.
71    // @ts-ignore
72    public toJSON() {
73        return {
74            type: EPaletteProviderType.Custom,
75            customType: ExampleMountainPaletteProvider.Name,
76            options: this.options,
77        };
78    }
79}
80
81// Register it for use by the builder api
82registerType(
83    EBaseType.PaletteProvider,
84    ExampleMountainPaletteProvider.Name,
85    (options: { stroke: string; fill: string }) => new ExampleMountainPaletteProvider(options)
86);
87
88export const drawExample = async (rootElement: string | HTMLDivElement) => {
89    // Build the surface
90    const { sciChartSurface, wasmContext } = await build2DChart(rootElement, {
91        surface: { theme: appTheme.SciChartJsTheme },
92        yAxes: {
93            type: EAxisType.NumericAxis,
94            options: { axisAlignment: EAxisAlignment.Left, visibleRange: new NumberRange(0, 1) },
95        },
96        // Add annotations
97        annotations: [
98            {
99                type: EAnnotationType.SVGTextAnnotation,
100                options: {
101                    text: "Builder API Demo",
102                    x1: 0.5,
103                    y1: 0.5,
104                    opacity: 0.33,
105                    yCoordShift: -26,
106                    xCoordinateMode: ECoordinateMode.Relative,
107                    yCoordinateMode: ECoordinateMode.Relative,
108                    horizontalAnchorPoint: EHorizontalAnchorPoint.Center,
109                    verticalAnchorPoint: EVerticalAnchorPoint.Center,
110                    fontSize: 36,
111                    fontWeight: "Bold",
112                },
113            },
114            {
115                type: EAnnotationType.SVGTextAnnotation,
116                options: {
117                    text: "Create SciChart charts with JSON Objects",
118                    x1: 0.5,
119                    y1: 0.5,
120                    yCoordShift: 26,
121                    opacity: 0.33,
122                    xCoordinateMode: ECoordinateMode.Relative,
123                    yCoordinateMode: ECoordinateMode.Relative,
124                    horizontalAnchorPoint: EHorizontalAnchorPoint.Center,
125                    verticalAnchorPoint: EVerticalAnchorPoint.Center,
126                    fontSize: 24,
127                    fontWeight: "Bold",
128                },
129            },
130        ],
131    });
132    // Build the series.
133    // By doing this separately we can easily get the reference to the series so we can add generated data to it
134    const [mountainSeries] = buildSeries(wasmContext, {
135        type: ESeriesType.MountainSeries,
136        options: {
137            paletteProvider: {
138                type: EPaletteProviderType.Custom,
139                customType: ExampleMountainPaletteProvider.Name,
140                options: { stroke: appTheme.MutedRed, fill: appTheme.VividOrange },
141            },
142            fillLinearGradient: {
143                startPoint: { x: 0, y: 0 },
144                endPoint: { x: 0, y: 1 },
145                gradientStops: [
146                    { color: appTheme.VividBlue, offset: 0 },
147                    { color: "Transparent", offset: 1 },
148                ],
149            },
150            stroke: appTheme.PaleSkyBlue,
151            strokeThickness: 3,
152            drawNaNAs: ELineDrawMode.PolyLine,
153            animation: { type: EAnimationType.Scale, options: { ease: "cubic" } },
154        },
155    });
156
157    // Create a dataSeries the normal way
158    const dataSeries = new XyDataSeries(wasmContext);
159    // Generate data
160    const POINTS = 1000;
161    const STEP = (3 * Math.PI) / POINTS;
162    for (let i = 0; i <= 1000; i++) {
163        let y = Math.abs(Math.sin(i * STEP));
164        if (y < 0.2) {
165            y = NaN;
166        }
167        dataSeries.append(i, y);
168    }
169    mountainSeries.dataSeries = dataSeries;
170    // Since we built the series separately, we have to manually add it to the surface
171    sciChartSurface.renderableSeries.add(mountainSeries);
172
173    return { sciChartSurface, wasmContext };
174};
175

Custom Types with Builder API - JavaScript

Overview

This example demonstrates how to extend the default functionalities of SciChart.js using JavaScript. It shows how to create a custom palette provider that dynamically overrides the fill and stroke of a Mountain Series chart based on specific data thresholds, while leveraging JSON configuration for flexible chart construction with the Builder API.

Technical Implementation

The implementation uses the SciChart.js Builder API to build a 2D chart using a JSON configuration. In the file drawExample.ts, the chart is configured with a numeric Y-Axis, custom annotations, and a Mountain Series whose look is dynamically altered by the custom palette provider (ExampleMountainPaletteProvider). This provider overrides the default rendering behavior for data points by checking if the Y value falls within a set range before applying custom colors. For a deeper dive into this approach, check out the Custom Types with Builder API - JavaScript Chart - SciChart documentation. Additionally, the use of JSON in defining chart properties is detailed in the Serialization and Deserialization of Charts - SciChart guide.

Features and Capabilities

The example incorporates several advanced features, including real-time data updates, dynamic handling of NaN values, and gradient fill techniques. It leverages WebGL rendering for high-performance updates and demonstrates advanced customization by overriding fill and stroke colors via a custom palette provider. These optimizations align with best practices discussed in the Performance Tips & Tricks | JavaScript Chart Documentation.

Integration and Best Practices

For developers working purely in JavaScript, this example provides a clear blueprint for integrating SciChart.js into any web project without relying on frameworks like React or Angular. The approach emphasizes the use of the Builder API for streamlined chart creation and customization, as outlined in the JavaScript Builder API Documentation. By using JSON configuration and custom types, the example encourages modularity and adherence to performance optimizations, making it easy to manage dynamic data and real-time updates. This serves as a solid foundation for building high-performance charts with customized visual behavior.

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