simple-chartjs/src/lib/Chart.js

Un module ChartJS simple d'utilisation, rapide et puissant !

const { ChartJSNodeCanvas } = require('chartjs-node-canvas');
const ChartJSDatalabels = require('chartjs-plugin-datalabels')

class Chart {
    /**
     * @typedef {object} ChartConfig
     * 
     * @property {object} identity
     * @property {object} identity.title
     * @property {string} identity.title.text
     * @property {string} identity.title.color
     * @property {object} identity.title.font
     * @property {number} identity.title.font.size
     * @property {string} identity.title.font.family
     * @property {object} identity.subtitle
     * @property {string} identity.subtitle.text
     * @property {string} identity.subtitle.color
     * @property {object} identity.subtitle.font
     * @property {number} identity.subtitle.font.size
     * @property {string} identity.subtitle.font.family
     * @property {'line' | 'bar' | 'radar' | 'doughnut' | 'polarArea' | 'bubble' | 'scatter'} identity.type
     * 
     * @property {object} sizes
     * @property {number} sizes.height
     * @property {number} sizes.width
     * 
     * @property {object} data
     * @property {object} data.font
     * @property {number} data.font.size
     * @property {string} data.font.family
     * @property {any[]} data.labels
     * @property {Graph[]} data.graphs
     * 
     * @property {object} options
     * @property {string} options.backgroundColor
     * @property {string} options.labelsColor
     * @property {boolean} options.displayValues
     */
    /**
     * @param {ChartConfig} config
     */
    constructor(config) {
        this.width = config.sizes.width;
        this.height = config.sizes.height;

        this.title = config.identity?.title;
        this.subtitle = config.identity?.subtitle;
        this.type = config.identity?.type || undefined;

        this.labels = config.data.labels || [];
        this.graphs = config.data.graphs;
        this.labelsFont = config.data.font;

        this.backgroundColour = config.options.backgroundColor;
        this.labelsColor = config.options.labelsColor;
        this.plugins = [];
        if(config.options.displayValues) this.plugins.push(ChartJSDatalabels);
    };

    /* RENDERING */
    /**
     * @returns {Promise<Buffer>}
     */
    async renderToBuffer() {
        return await this.#getCanvas().renderToBuffer(this.#renderToData());
    };

    /* UTIL */
    /**
     * @returns {ChartJSNodeCanvas}
     */
    #getCanvas() {
        return new ChartJSNodeCanvas({
            plugins: this.plugins,
            type: this.type,
            width: this.width,
            height: this.height,
            backgroundColour: this.backgroundColour
        });
    };
    #renderToData() {
        return ({
            plugins: this.plugins,
            type: this.type,
            data: {
                labels: this.labels,
                datasets: this.graphs
            }, options: {
                plugins: {
                    title: {
                        display: this.title?.text ? true : false,
                        text: this.title.text,
                        color: this.title.color,
                        font: {
                            size: this.title.font?.size,
                            family: this.title.font?.family
                        }
                    }, subtitle: {
                        display: this.subtitle?.text ? true : false,
                        text: this.subtitle.text,
                        color: this.subtitle.color,
                        font: {
                            size: this.subtitle.font?.size,
                            family: this.subtitle.font?.family
                        }
                    }, legend: {
                        labels: {
                            color: this.labelsColor,
                            font: this.labelsFont
                        }
                    }
                }
            }
        })
    };
};

module.exports = Chart;