93 lines
2.2 KiB
JavaScript
93 lines
2.2 KiB
JavaScript
const { createCanvas } = require("canvas");
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const Chart = require("chart.js/auto");
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const { backgroundColors, borderColors } = require("./canvas-colors");
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const { isObject, defaultsDeep, isNumber } = require("lodash");
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exports.canvastest = function (req, res) {
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console.log("Incoming test request.", req);
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res.status(200).send("OK");
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};
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exports.canvas = function (req, res) {
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const { w, h, values, keys, override } = req.body;
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console.log("Incoming Canvas Request:", w, h, values, keys, override);
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// Gate required values
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if (!values || !keys) {
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res.status(400).send("Missing required data");
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return;
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}
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// Override must be an object if it exists
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if (override && !isObject(override)) {
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res.status(400).send("Override must be an object");
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return;
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}
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// Set the default Width and Height
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let [width, height] = [500, 275];
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// Allow for custom width and height
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if (isNumber(w)) {
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width = w;
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}
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if (isNumber(h)) {
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height = h;
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}
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const configuration = {
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type: "doughnut",
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data: {
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labels: keys,
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datasets: [
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{
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data: values,
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backgroundColor: backgroundColors,
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borderColor: borderColors,
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borderWidth: 1
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}
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]
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},
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options: {
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devicePixelRatio: 4,
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responsive: false,
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maintainAspectRatio: true,
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circumference: 180,
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rotation: -90,
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plugins: {
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legend: {
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labels: {
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boxWidth: 20,
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font: {
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family: "'Montserrat'",
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size: 10,
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style: "normal",
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weight: "normal"
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}
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},
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position: "left"
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}
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}
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}
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};
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// If we have a valid override object, merge it with the default configuration object.
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// This allows for you to override the default configuration with a custom one.
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const defaults = () => {
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if (!override || !isObject(override)) {
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return configuration;
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}
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return defaultsDeep(override, configuration);
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};
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res.status(200).send(
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(() => {
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const canvas = createCanvas(width, height);
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const ctx = canvas.getContext("2d");
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new Chart(ctx, defaults());
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return canvas.toDataURL();
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})()
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);
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};
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