feat: Enable HttpServer on iOS when offline

In iOS, we disabled HttpServer for all cozy-apps as the WebView API may
behave differently

The side effect is that we cannot open those app when offline as we
cannot inject minimal code to make them work without network access

So we want to enable HttpServer on those apps when we detect the app to
be offline

Related PR: #486

src/libs/httpserver/httpServerProvider.tsx

@@ -149,7 +149,7 @@ export const HttpServerProvider = (
       }
 
       await setCookie(cookie, client)
-      const rawHtml = await getIndexForFqdnAndSlug(fqdn, slug)
+      const rawHtml = await getIndexForFqdnAndSlug(fqdn, slug, source)
 
       if (!rawHtml) {
         return {

src/libs/httpserver/indexGenerator.ts

@@ -13,6 +13,7 @@ import {
   prepareAssets
 } from '/libs/httpserver/copyAllFilesFromBundleAssets'
 import { TemplateValues } from '/libs/httpserver/indexDataFetcher'
+import { HtmlSource } from '/libs/httpserver/models'
 import {
   getCurrentAppConfigurationForFqdnAndSlug,
   setCurrentAppVersionForFqdnAndSlug
@@ -87,11 +88,17 @@ const isSlugInBlocklist = (currentSlug: string): boolean =>
 
 export const getIndexForFqdnAndSlug = async (
   fqdn: string,
-  slug: string
+  slug: string,
+  source: HtmlSource
 ): Promise<string | false> => {
   if (shouldDisableGetIndex()) return false // Make cozy-app hosted by webpack-dev-server work with HTTPServer
 
-  if (!isSlugInAllowlist(slug) || isSlugInBlocklist(slug)) return false
+  if (
+    (!isSlugInAllowlist(slug) || isSlugInBlocklist(slug)) &&
+    source !== 'cache'
+  ) {
+    return false
+  }
 
   await initLocalBundleIfNotExist(fqdn, slug)