Bar graph added.

node_modules/vega-cli/src/render.js

@@ -0,0 +1,64 @@
+const vega = require('vega'),
+      path = require('path'),
+      args = require('./args'),
+      read = require('./read');
+
+function load(file) {
+  return require(path.resolve(file));
+}
+
+const Levels = {
+  error: vega.Error,
+  warn:  vega.Warn,
+  info:  vega.Info,
+  debug: vega.Debug
+};
+
+module.exports = function(type, callback, opt) {
+  // parse command line arguments
+  const arg = args(type);
+
+  // set baseURL, if specified. default to input spec directory
+  const base = arg.base || (arg._[0] ? path.dirname(arg._[0]) : null);
+
+  // set log level, defaults to logging warning messages
+  const loglevel = Levels[String(arg.loglevel).toLowerCase()] || vega.Warn;
+
+  // load config file, if specified
+  const config = arg.config ? load(arg.config) : null;
+
+  // set output image scale factor
+  const scale = arg.scale || undefined;
+
+  // use a seeded random number generator, if specified
+  if (typeof arg.seed !== 'undefined') {
+    if (Number.isNaN(arg.seed)) throw 'Illegal seed value: must be a valid number.';
+    vega.setRandom(vega.randomLCG(arg.seed));
+  }
+
+  // locale options, load custom number/time formats if specified
+  const locale = {
+    number: arg.format ? load(arg.format) : null,
+    time: arg.timeFormat ? load(arg.timeFormat) : null
+  };
+
+  // instantiate view and invoke headless render method
+  function render(spec) {
+    const view = new vega.View(vega.parse(spec, config), {
+        locale: locale,                         // set locale options
+        loader: vega.loader({baseURL: base}),   // load files from base path
+        logger: vega.logger(loglevel, 'error'), // route all logging to stderr
+        renderer: 'none'                        // no primary renderer needed
+      }).finalize();                            // clear any timers, etc
+
+    return (type === 'svg'
+        ? view.toSVG(scale)
+        : view.toCanvas(scale, opt)
+      ).then(_ => callback(_, arg));
+  }
+
+  // read input from file or stdin
+  read(arg._[0] || null)
+    .then(text => render(JSON.parse(text)))
+    .catch(err => console.error(err)); // eslint-disable-line no-console
+};