Implement machinery for allowing extensions

This commit (and the PR to which it belongs)
moves auspice from a component of nextstrain
to a stand alone tool which can be extended
(e.g. with aesthetic or functional changes).
The auspice seen on nextstrain.org will
eventually be one such extension.

server.js

@@ -7,6 +7,7 @@ const expressStaticGzip = require("express-static-gzip");
 const charon = require("./src/server/charon");
 const globals = require("./src/server/globals");
 const compression = require('compression');
+const fs = require('fs');
 const argparse = require('argparse');
 const version = require('./src/version').version;
 
@@ -25,6 +26,7 @@ if (!globals.isNpmGlobalInstall()) {
   parser.addArgument('--dev', {action: "storeTrue", help: "Run (client) in development mode (hot reloading etc)"});
 }
 parser.addArgument('--data', {help: "Directory where local datasets are sourced"});
+parser.addArgument('--extend', {help: "tmp / wip"});
 parser.addArgument('--narratives', {help: "Directory where local narratives are sourced"});
 const args = parser.parseArgs();
 
@@ -38,6 +40,9 @@ app.use(compression());
 if (args.dev) {
   /* if we are in dev-mode, we need to import specific libraries & set up hot reloading */
   const webpack = require("webpack"); // eslint-disable-line
+  if (args.extend) {
+    process.env.EXTEND_AUSPICE_JSON = JSON.stringify(JSON.parse(fs.readFileSync(args.extend, {encoding: 'utf8'})));
+  }
   const webpackConfig = require(process.env.WEBPACK_CONFIG ? process.env.WEBPACK_CONFIG : './webpack.config.dev');  // eslint-disable-line
   const compiler = webpack(webpackConfig);
   app.use(require("webpack-dev-middleware")( // eslint-disable-line

src/index.js

@@ -18,6 +18,8 @@ import "./css/boxed.css";
 import "./css/select.css";
 import "./css/narrative.css";
 
+import "./util/extensions"
+
 const store = configureStore();
 
 /* set up non-redux state storage for the animation - use this conservitavely! */

src/util/extensions.js

@@ -0,0 +1,20 @@
+
+
+/* set up time -- only runs once no matter how many components import this */
+
+const registry = (() => {
+  console.log("EXTENSTIONS.jS");
+  if (!process.env.EXTENSION_DATA) {
+    console.log("no EXTENSION_DATA found")
+    return {};
+  }
+  const extensionJson = JSON.parse(process.env.EXTENSION_DATA);
+  console.log("extensionJson", extensionJson);
+  return extensionJson;
+})();
+
+
+export const getExtension = (what) => {
+  console.log("trying to get:", what)
+  return "something";
+}

webpack.config.dev.js

@@ -20,7 +20,8 @@ module.exports = {
     new webpack.HotModuleReplacementPlugin(),
     new webpack.DefinePlugin({
       "process.env": {
-        NODE_ENV: JSON.stringify("dev")
+	NODE_ENV: JSON.stringify("dev"),
+	EXTENSION_DATA: JSON.stringify(process.env.EXTEND_AUSPICE_JSON)
       }
     }),
     new webpack.NoEmitOnErrorsPlugin()