Removing unneeded props (issue #12).

Moved code into separate modules.

server/page-renderer.js

@@ -0,0 +1,37 @@
+const Bluebird = require('bluebird');
+const FS = Bluebird.promisifyAll(require('fs'));
+const ReactDOMServer = require('react-dom/server');
+const CrossFetch = require('cross-fetch');
+const FrontEnd = require('./client/front-end');
+
+const NGINX_HOST = process.env.NGINX_HOST;
+const CACHE_SIZE = 500;
+const HTML_TEMPLATE = `${__dirname}/client/index.html`;
+
+async function generate(path, target) {
+    // retrieve cached JSON through Nginx
+    let host = `http://${NGINX_HOST}`;
+    // create a fetch() that remembers the URLs used
+    let sourceURLs = [];
+    let fetch = (url, options) => {
+        if (url.startsWith(host)) {
+            sourceURLs.push(url.substr(host.length));
+        }
+        return CrossFetch(url, options);
+    };
+    let options = { host, path, target, fetch };
+    let rootNode = await FrontEnd.render(options);
+    let appHTML = ReactDOMServer.renderToString(rootNode);
+    let htmlTemplate = await FS.readFileAsync(HTML_TEMPLATE, 'utf-8');
+    let html = htmlTemplate.replace(`<!--REACT-->`, appHTML);
+    if (target === 'hydrate') {
+        // add <noscript> tag to redirect to SEO version
+        let meta = `<meta http-equiv=refresh content="0; url=?js=0">`;
+        html += `<noscript>${meta}</noscript>`;
+    }
+    return { path, target, sourceURLs, html };
+}
+
+module.exports = {
+    generate,
+};