From aa4600b5884aee06a70660f34a7e20a4d296a2af Mon Sep 17 00:00:00 2001
From: Lucien Cartier-Tilet <lucien@phundrak.com>
Date: Sun, 10 May 2020 12:00:47 +0200
Subject: [PATCH] Sitemap query now fully asynchronous

Sitemap generation is now independent from the navbar generation, and
it will be added to the navbar only once the navbar has been created.

Also, better style for code.
---
 web/dart/main.dart          |  6 +++---
 web/dart/navbar.dart        | 12 ------------
 web/dart/parse_sitemap.dart | 37 ++++++++++++++++++++++++++++++-------
 3 files changed, 33 insertions(+), 22 deletions(-)

diff --git a/web/dart/main.dart b/web/dart/main.dart
index 5b17663..ca703c1 100644
--- a/web/dart/main.dart
+++ b/web/dart/main.dart
@@ -1,9 +1,9 @@
 import './reorganize_html.dart' show reorganizeHtml;
 import './theme.dart' show enableThemeChanger, setTheme;
+import './parse_sitemap.dart' show getSitemap;
 
 Future<void> main() async {
   await setTheme();
-  await reorganizeHtml().then((_) {
-    enableThemeChanger();
-  });
+  await reorganizeHtml().then((_) => enableThemeChanger());
+  await getSitemap();
 }
diff --git a/web/dart/navbar.dart b/web/dart/navbar.dart
index 2ea1ec9..8eae5e9 100644
--- a/web/dart/navbar.dart
+++ b/web/dart/navbar.dart
@@ -28,18 +28,6 @@ Future<Element> makePages() async {
   var pages = Element.ul()
     ..attributes['id'] = 'drop-page'
     ..classes.add('dropdown');
-  await parseSitemap().then((final sitemap) => {
-        sitemap.forEach((url, name) {
-          final link = Element.li()
-            ..classes.add('dropdown-item')
-            ..insertAdjacentElement(
-                'afterBegin',
-                Element.a()
-                  ..attributes['href'] = url
-                  ..innerText = name);
-          pages.insertAdjacentElement('beforeEnd', link);
-        })
-      });
   return Element.li()
     ..append(Element.a()
       ..attributes['href'] = 'javascript:void(0)'
diff --git a/web/dart/parse_sitemap.dart b/web/dart/parse_sitemap.dart
index c0ca0d7..67dc69c 100644
--- a/web/dart/parse_sitemap.dart
+++ b/web/dart/parse_sitemap.dart
@@ -1,15 +1,15 @@
-import 'dart:html' show HttpRequest;
+import 'dart:html' as html show HttpRequest, Element, querySelector;
 
 import 'package:html/parser.dart' show parse;
-import 'package:html/dom.dart' show Element;
+import 'package:html/dom.dart' as dom show Element;
 
 final excluded_keywords = ['index', 'CONTRIBUTING', 'LICENSE', 'README'];
 
 // Get the sitemap content
-Future<String> getSitemap() async {
+Future<String> fetchRemoteSitemap() async {
   const path = 'sitemap.html';
   try {
-    return await HttpRequest.getString(path);
+    return await html.HttpRequest.getString(path);
   } catch (e) {
     print('Couldn’t open $path');
   }
@@ -17,10 +17,10 @@ Future<String> getSitemap() async {
 }
 
 // Parse the list of elements and detect pages from this list
-Map<String, String> detectPages(List<Element> sitemap, [String prefix]) {
+Map<String, String> detectPages(List<dom.Element> sitemap, [String prefix]) {
   final links = <String, String>{};
   for (var elem in sitemap) {
-    for(var kw in excluded_keywords) {
+    for (var kw in excluded_keywords) {
       if (elem.outerHtml.contains(kw)) {
         continue;
       }
@@ -42,7 +42,30 @@ Map<String, String> detectPages(List<Element> sitemap, [String prefix]) {
 // This function returns a Map which contains all links to languages detected
 // from the sitemap.
 Future<Map<String, String>> parseSitemap() async {
-  final content = await getSitemap();
+  final content = await fetchRemoteSitemap();
   final sitemap = parse(content).getElementsByClassName('org-ul')[0].children;
   return detectPages(sitemap);
 }
+
+Future sleep(Duration time) async {
+  return Future.delayed(time);
+}
+
+Future<html.Element> getSitemap() async {
+  final sitemap = await parseSitemap();
+  final pages = <html.Element>[];
+  sitemap.forEach((url, name) {
+    final link = html.Element.li()
+      ..classes.add('dropdown-item')
+      ..append(html.Element.a()
+        ..attributes['href'] = url
+        ..innerText = name);
+    pages.add(link);
+  });
+  var drop_container;
+  do {
+    await sleep(Duration(seconds: 1));
+    drop_container = html.querySelector('#drop-page');
+  } while (drop_container != null);
+  pages.forEach((link) => drop_container.append(link));
+}