Initial commit

.gitignore

@@ -0,0 +1,130 @@
+venv
+
+### Vim ###
+[._]*.s[a-w][a-z]
+[._]s[a-w][a-z]
+*.un~
+Session.vim
+.netrwhist
+*~
+
+
+### OSX ###
+.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must end with two \r
+Icon
+
+
+# Thumbnails
+._*
+
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+
+
+### Python ###
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+env/
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*,cover
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/
+
+
+### Node ###
+# Logs
+logs
+*.log
+npm-debug.log*
+
+# Runtime data
+pids
+*.pid
+*.seed
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+
+# Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (http://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directory
+# https://docs.npmjs.com/misc/faq#should-i-check-my-node-modules-folder-into-git
+node_modules
+

charts.js

@@ -0,0 +1,35 @@
+const DEFAULT_COLORS = {
+  blue: 'rgba(54, 162, 235, 0.5)',
+  orange: 'rgba(255, 159, 64, 0.5)',
+  purple: 'rgba(153, 102, 255, 0.5)',
+  red: 'rgba(255, 99, 132, 0.5)',
+  yellow: 'rgba(255, 205, 86, 0.5)',
+  green: 'rgba(75, 192, 192, 0.5)',
+  grey: 'rgba(201, 203, 207, 0.5)',
+};
+
+const DEFAULT_COLOR_WHEEL = Object.values(DEFAULT_COLORS);
+
+function addBackgroundColors(chart) {
+  if (chart.data && chart.data.datasets && Array.isArray(chart.data.datasets)) {
+    chart.data.datasets.forEach((dataset, idx) => {
+      if (!dataset.backgroundColor) {
+        if (chart.type === 'pie' || chart.type === 'doughnut') {
+          dataset.backgroundColor = dataset.data.map((_, idx) => {
+            // Return a color for each value.
+            return DEFAULT_COLOR_WHEEL[idx % DEFAULT_COLOR_WHEEL.length];
+          });
+        } else {
+          // Return a color for each dataset.
+          dataset.backgroundColor = DEFAULT_COLOR_WHEEL[idx % DEFAULT_COLOR_WHEEL.length];
+        }
+      }
+    });
+  }
+}
+
+module.exports = {
+  DEFAULT_COLORS,
+  DEFAULT_COLOR_WHEEL,
+  addBackgroundColors,
+};

index.js

@@ -0,0 +1,128 @@
+const path = require('path');
+
+const ChartjsNode = require('chartjs-node');
+const express = require('express');
+const expressNunjucks = require('express-nunjucks');
+const winston = require('winston');
+const { toJson } = require('really-relaxed-json');
+
+const { addBackgroundColors, DEFAULT_COLOR_WHEEL } = require('./charts');
+
+const logger = new (winston.Logger)({
+  transports: [
+    new (winston.transports.Console)({ timestamp: true, colorize: true }),
+  ],
+});
+
+const app = express();
+
+const isDev = app.get('env') === 'development';
+
+app.set('views', `${__dirname}/templates`);
+app.use(express.static('public'));
+
+expressNunjucks(app, {
+  watch: isDev,
+  noCache: isDev,
+});
+
+app.get('/', (req, res) => {
+  res.render('index');
+});
+
+app.get('/robots.txt', (req, res) => {
+  res.sendFile(path.join(__dirname, './templates/robots.txt'));
+});
+
+app.get('/chart', (req, res) => {
+  if (!req.query.c) {
+    res.send('You are missing variable `c`');
+    return;
+  }
+
+  let height = 300;
+  let width = 500;
+  if (req.h || req.height) {
+    const heightNum = parseInt(req.h || req.height, 10);
+    if (!isNaN(heightNum)) {
+      height = heightNum;
+    }
+  }
+  if (req.w || req.width) {
+    const heightNum = parseInt(req.w || req.width, 10);
+    if (!isNaN(widthNum)) {
+      width = widthNum;
+    }
+  }
+
+  const chart = JSON.parse(toJson(req.query.c));
+
+  if (chart.type === 'donut') {
+    // Fix spelling...
+    chart.type === 'doughnut';
+  }
+
+  if (typeof chart.options === 'undefined') {
+    // Implement default options
+    chart.options = {};
+    if (chart.type === 'bar' || chart.type === 'line') {
+      chart.options = {
+        scales: {
+          yAxes: [{
+            ticks: {
+              beginAtZero: true,
+            },
+          }],
+        },
+      };
+      addBackgroundColors(chart);
+    } else if (chart.type === 'radar') {
+      addBackgroundColors(chart);
+    } else if (chart.type === 'pie' || chart.type === 'doughnut') {
+      addBackgroundColors(chart);
+    }
+  }
+
+  console.log(JSON.stringify(chart))
+
+  const chartNode = new ChartjsNode(width, height);
+  chartNode.drawChart(chart).then(() => {
+    return chartNode.getImageBuffer('image/png');
+  }).then(buf => {
+    res.writeHead(200, {
+      'Content-Type': 'image/png',
+      'Content-Length': buf.length,
+    });
+    res.end(buf);
+    chartNode.destroy();
+  });
+});
+
+if (!isDev) {
+  function gracefulShutdown() {
+    logger.info('Received kill signal, shutting down gracefully.');
+    server.close(() => {
+      logger.info('Closed out remaining connections.');
+      process.exit();
+    });
+
+    // if after
+    setTimeout(() => {
+      logger.error('Could not close connections in time, forcefully shutting down');
+      process.exit();
+    }, 10 * 1000);
+  }
+
+  // listen for TERM signal .e.g. kill
+  process.on('SIGTERM', gracefulShutdown);
+
+  // listen for INT signal e.g. Ctrl-C
+  process.on('SIGINT', gracefulShutdown);
+}
+
+const port = process.env.PORT || 3400;
+const server = app.listen(port);
+logger.info('NODE_ENV:', process.env.NODE_ENV);
+logger.info('Running on port', port);
+
+module.exports = app;

package.json

@@ -0,0 +1,15 @@
+{
+  "name": "staticchart",
+  "version": "1.0.0",
+  "main": "index.js",
+  "license": "None",
+  "dependencies": {
+    "chart.js": "^2.7.3",
+    "chartjs-node": "^1.7.1",
+    "express": "^4.16.4",
+    "express-nunjucks": "^2.2.3",
+    "nunjucks": "^3.1.7",
+    "really-relaxed-json": "^0.2.24",
+    "winston": "^2.3.1"
+  }
+}