Custom Types with Builder API

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

Fullscreen

Edit

 Edit

Docs

drawExample.ts

index.html

vanilla.ts

theme.ts

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

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.

SciChart Ltd, 16 Beaufort Court, Admirals Way, Docklands, London, E14 9XL.