chartjs-node-canvas/dist/chartJSNodeCanvasBase.d.ts

A node renderer for Chart.js using canvas.

import { Readable } from 'stream';
import { Chart as ChartJS, ChartComponentLike } from 'chart.js/auto';
import { createCanvas, registerFont, Image } from 'canvas';
export type ChartJSNodeCanvasPlugins = {
    /**
     * Global plugins, see https://www.chartjs.org/docs/latest/developers/plugins.html.
     */
    readonly modern?: ReadonlyArray<string | ChartComponentLike>;
    /**
     * This will work for plugins that `require` ChartJS themselves.
     */
    readonly requireChartJSLegacy?: ReadonlyArray<string>;
    /**
     * This should work for any plugin that expects a global Chart variable.
     */
    readonly globalVariableLegacy?: ReadonlyArray<string>;
    /**
     * This will work with plugins that just return a plugin object and do no specific loading themselves.
     */
    readonly requireLegacy?: ReadonlyArray<string>;
};
export type ChartCallback = (chartJS: typeof ChartJS) => void | Promise<void>;
export type CanvasType = 'pdf' | 'svg';
export type MimeType = 'image/png' | 'image/jpeg';
export type Canvas = HTMLCanvasElement & {
    toBuffer(callback: (err: Error | null, result: Buffer) => void, mimeType?: string, config?: any): void;
    toBuffer(mimeType?: string, config?: any): Buffer;
    createPNGStream(config?: any): Readable;
    createJPEGStream(config?: any): Readable;
    createPDFStream(config?: any): Readable;
};
export interface ChartJSNodeCanvasOptions {
    /**
     * The width of the charts to render, in pixels.
     */
    readonly width: number;
    /**
     * The height of the charts to render, in pixels.
     */
    readonly height: number;
    /**
     * Optional callback which is called once with a new ChartJS global reference as the only parameter.
     */
    readonly chartCallback?: ChartCallback;
    /**
     * Optional canvas type ('PDF' or 'SVG'), see the [canvas pdf doc](https://github.com/Automattic/node-canvas#pdf-output-support).
     */
    readonly type?: CanvasType;
    /**
     * Optional plugins to register.
     */
    readonly plugins?: ChartJSNodeCanvasPlugins;
    /**
     * Optional background color for the chart, otherwise it will be transparent. Note, this will apply to all charts. See the [fillStyle](https://www.w3schools.com/tags/canvas_fillstyle.asp) canvas API used for possible values.
     */
    readonly backgroundColour?: string;
}
export declare abstract class ChartJSNodeCanvasBase {
    protected readonly _width: number;
    protected readonly _height: number;
    protected readonly _chartJs: typeof ChartJS;
    protected readonly _createCanvas: typeof createCanvas;
    protected readonly _registerFont: typeof registerFont;
    protected readonly _image: typeof Image;
    protected readonly _type?: CanvasType;
    /**
     * Create a new instance of CanvasRenderService.
     *
     * @param options Configuration for this instance
     */
    constructor(options: ChartJSNodeCanvasOptions);
    /**
     * Use to register the font with Canvas to use a font file that is not installed as a system font, this must be done before the Canvas is created.
     *
     * @param path The path to the font file.
     * @param options The font options.
     * @example
     * registerFont('comicsans.ttf', { family: 'Comic Sans' });
     */
    registerFont(path: string, options: {
        readonly family: string;
        readonly weight?: string;
        readonly style?: string;
    }): void;
    protected initialize(options: ChartJSNodeCanvasOptions): typeof ChartJS;
}