Initial commit

lib/server/readCategories.js

@@ -0,0 +1,105 @@
+/**
+ * Copyright (c) 2017-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+ const CWD = process.cwd();
+
+const Metadata = require('../core/metadata.js');
+const fs = require('fs');
+let languages;
+if (fs.existsSync(CWD + '/languages.js')) {
+  languages = require(CWD + '/languages.js');
+} else {
+  languages = [{
+    enabled: true,
+    name: 'English',
+    tag: 'en',
+  }];
+}
+function readCategories(layout) {
+
+  const enabledLanguages = [];
+  languages.filter(lang => lang.enabled).map(lang => {
+    enabledLanguages.push(lang.tag);
+  });
+
+  const allCategories = {};
+
+  for (let k = 0; k < enabledLanguages.length; ++k) {
+    const language = enabledLanguages[k];
+
+    const metadatas = Metadata.filter(metadata => {
+    return metadata.layout === layout &&
+        metadata.language === language;
+    });
+
+    // Build a hashmap of article_id -> metadata
+    const articles = {};
+    for (let i = 0; i < metadatas.length; ++i) {
+      const metadata = metadatas[i];
+      articles[metadata.id] = metadata;
+    }
+
+    // Build a hashmap of article_id -> previous_id
+    const previous = {};
+    for (let i = 0; i < metadatas.length; ++i) {
+      const metadata = metadatas[i];
+      if (metadata.next) {
+        if (!articles[metadata.next]) {
+          throw new Error(
+            '`next: ' + metadata.next + '` in ' + metadata.id + " doesn't exist"
+          );
+        }
+        previous[articles[metadata.next].id] = metadata.id;
+      }
+    }
+
+    // Find the first element which doesn't have any previous
+    let first = null;
+    for (let i = 0; i < metadatas.length; ++i) {
+      const metadata = metadatas[i];
+      if (!previous[metadata.id]) {
+        first = metadata;
+        break;
+      }
+    }
+
+    const categories = [];
+    let currentCategory = null;
+
+    let metadata = first;
+    let i = 0;
+    while (metadata && i++ < 1000) {
+      if (!currentCategory || metadata.category !== currentCategory.name) {
+        currentCategory && categories.push(currentCategory);
+        currentCategory = {
+          name: metadata.category,
+          links: [],
+        };
+      }
+      currentCategory.links.push(metadata);
+      metadata = articles[metadata.next];
+    }
+    categories.push(currentCategory);
+
+    allCategories[language] = categories;
+  }
+
+  fs.writeFileSync(
+    __dirname + '/../core/' + layout + 'Categories.js',
+    '/**\n' +
+      ' * @generated\n' +
+      ' */\n' +
+      'module.exports = ' +
+      JSON.stringify(allCategories, null, 2) +
+      ';'
+  );
+
+}
+
+module.exports = readCategories;