chartjs-node-canvas/dist/chartJSNodeCanvas.js

A node renderer for Chart.js using canvas.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.ChartJSNodeCanvas = void 0;
const chartJSNodeCanvasBase_1 = require("./chartJSNodeCanvasBase");
class ChartJSNodeCanvas extends chartJSNodeCanvasBase_1.ChartJSNodeCanvasBase {
    /**
     * Render to a data url.
     * @see https://github.com/Automattic/node-canvas#canvastodataurl
     *
     * @param configuration The Chart JS configuration for the chart to render.
     * @param mimeType The image format, `image/png` or `image/jpeg`.
     */
    renderToDataURL(configuration, mimeType = 'image/png') {
        const chart = this.renderChart(configuration);
        return new Promise((resolve, reject) => {
            if (!chart.canvas) {
                return reject(new Error('Canvas is null'));
            }
            const canvas = chart.canvas;
            canvas.toDataURL(mimeType, (error, png) => {
                chart.destroy();
                if (error) {
                    return reject(error);
                }
                return resolve(png);
            });
        });
    }
    /**
     * Render to a data url synchronously.
     * @see https://github.com/Automattic/node-canvas#canvastodataurl
     *
     * @param configuration The Chart JS configuration for the chart to render.
     * @param mimeType The image format, `image/png` or `image/jpeg`.
     */
    renderToDataURLSync(configuration, mimeType = 'image/png') {
        const chart = this.renderChart(configuration);
        if (!chart.canvas) {
            throw new Error('Canvas is null');
        }
        const canvas = chart.canvas;
        const dataUrl = canvas.toDataURL(mimeType);
        // Use this to destroy any chart instances that are created.
        // This will clean up any references stored to the chart object within Chart.js, along with any associated event listeners attached by Chart.js.
        // This must be called before the canvas is reused for a new chart.
        chart.destroy();
        return dataUrl;
    }
    /**
     * Render to a buffer.
     * @see https://github.com/Automattic/node-canvas#canvastobuffer
     *
     * @param configuration The Chart JS configuration for the chart to render.
     * @param mimeType A string indicating the image format. Valid options are `image/png`, `image/jpeg` (if node-canvas was built with JPEG support) or `raw` (unencoded ARGB32 data in native-endian byte order, top-to-bottom). Defaults to `image/png` for image canvases, or the corresponding type for PDF or SVG canvas.
     */
    renderToBuffer(configuration, mimeType = 'image/png') {
        const chart = this.renderChart(configuration);
        return new Promise((resolve, reject) => {
            if (!chart.canvas) {
                throw new Error('Canvas is null');
            }
            const canvas = chart.canvas;
            canvas.toBuffer((error, buffer) => {
                chart.destroy();
                if (error) {
                    return reject(error);
                }
                return resolve(buffer);
            }, mimeType);
        });
    }
    /**
     * Render to a buffer synchronously.
     * @see https://github.com/Automattic/node-canvas#canvastobuffer
     *
     * @param configuration The Chart JS configuration for the chart to render.
     * @param mimeType A string indicating the image format. Valid options are `image/png`, `image/jpeg` (if node-canvas was built with JPEG support), `raw` (unencoded ARGB32 data in native-endian byte order, top-to-bottom), `application/pdf` (for PDF canvases) and image/svg+xml (for SVG canvases). Defaults to `image/png` for image canvases, or the corresponding type for PDF or SVG canvas.
     */
    renderToBufferSync(configuration, mimeType = 'image/png') {
        const chart = this.renderChart(configuration);
        if (!chart.canvas) {
            throw new Error('Canvas is null');
        }
        const canvas = chart.canvas;
        const buffer = canvas.toBuffer(mimeType);
        chart.destroy();
        return buffer;
    }
    /**
     * Render to a stream.
     * @see https://github.com/Automattic/node-canvas#canvascreatepngstream
     *
     * @param configuration The Chart JS configuration for the chart to render.
     * @param mimeType A string indicating the image format. Valid options are `image/png`, `image/jpeg` (if node-canvas was built with JPEG support), `application/pdf` (for PDF canvases) and image/svg+xml (for SVG canvases). Defaults to `image/png` for image canvases, or the corresponding type for PDF or SVG canvas.
     */
    renderToStream(configuration, mimeType = 'image/png') {
        const chart = this.renderChart(configuration);
        if (!chart.canvas) {
            throw new Error('Canvas is null');
        }
        const canvas = chart.canvas;
        setImmediate(() => chart.destroy());
        switch (mimeType) {
            case 'image/png':
                return canvas.createPNGStream();
            case 'image/jpeg':
                return canvas.createJPEGStream();
            case 'application/pdf':
                return canvas.createPDFStream();
            default:
                throw new Error(`Un-handled mimeType: ${mimeType}`);
        }
    }
    renderChart(configuration) {
        const canvas = this._createCanvas(this._width, this._height, this._type);
        canvas.style = canvas.style || {};
        configuration.options = configuration.options || {};
        configuration.options.responsive = false;
        // Disable animation (otherwise charts will throw exceptions)
        configuration.options.animation = false;
        const context = canvas.getContext('2d');
        global.Image = this._image; // Some plugins use this API
        const chart = new this._chartJs(context, configuration);
        delete global.Image;
        return chart;
    }
}
exports.ChartJSNodeCanvas = ChartJSNodeCanvas;
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