Modifications to allow running the application from an IIS virtual directory (#59)

Author: dayport

README.md

@@ -263,5 +263,63 @@ This strategy will always try the network first for all resources and then fall
 
 This strategy is completely safe to use and is primarily useful for offline-only scenarios since it isn't giving any performance benefits.
 
+## .Net Core Application hosted as Virtual Directory
+You can now specify a specific BaseURL if you plan to host your application as a Virtual Directory in IIS:
+
+```c#
+private const string _baseURL = "/PWAApp";
+
+public void ConfigureServices(IServiceCollection services)
+{
+    services.AddMvc();
+    services.AddServiceWorker(new PwaOptions
+    {
+        BaseRoute = _baseURL;
+        Strategy = ServiceWorkerStrategy.CacheFirst
+    });
+}
+
+public void Configure(IApplicationBuilder app, IHostingEnvironment env)
+{
+    //...
+    app.UsePathBase(_baseURL);
+    //...
+}
+```
+
+...or in `appsettings.json`:
+
+```json
+{
+  "serviceworker": {
+    "baseRoute": "/PWAApp",
+    "strategy": "cacheFirst"
+  }
+}
+```
+
+Make sure to update your `wwwroot/manifest.json` file:
+
+```json
+{
+  "name": "Awesome Application",
+  "short_name": "Awesome",
+  "description": "The most awesome application in the world",
+  "icons": [
+    {
+      "src": "/PWAApp/img/icon192x192.png",
+      "sizes": "192x192"
+    },
+    {
+      "src": "/PWAApp/img/icon512x512.png",
+      "sizes": "512x512"
+    }
+  ],
+  "display": "standalone",
+  "start_url": "/PWAApp"
+}
+```
+
+
 ## License
 [Apache 2.0](LICENSE)

src/PwaController.cs

@@ -42,7 +42,7 @@ public async Task<IActionResult> ServiceWorkerAsync()
                 string modified = js
                     .Replace("{version}", _options.CacheId + "::" + _options.Strategy)
                     .Replace("{routes}", string.Join(",", _options.RoutesToPreCache.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries).Select(r => "'" + r.Trim() + "'")))
-                    .Replace("{offlineRoute}", _options.OfflineRoute);
+                    .Replace("{offlineRoute}", _options.BaseRoute + _options.OfflineRoute);
 
                 return Content(modified);
             }

src/PwaOptions.cs

@@ -16,6 +16,7 @@ public PwaOptions()
             CacheId = Constants.DefaultCacheId;
             Strategy = ServiceWorkerStrategy.CacheFirstSafe;
             RoutesToPreCache = "";
+            BaseRoute = "";
             OfflineRoute = Constants.Offlineroute;
             RegisterServiceWorker = true;
             RegisterWebmanifest = true;
@@ -29,6 +30,7 @@ internal PwaOptions(IConfiguration config)
         {
             CacheId = config["pwa:cacheId"] ?? CacheId;
             RoutesToPreCache = config["pwa:routesToPreCache"] ?? RoutesToPreCache;
+            BaseRoute = config["pwa:baseRoute"] ?? BaseRoute;
             OfflineRoute = config["pwa:offlineRoute"] ?? OfflineRoute;
 
             if (bool.TryParse(config["pwa:registerServiceWorker"] ?? "true", out bool register))
@@ -78,6 +80,11 @@ internal PwaOptions(IConfiguration config)
         /// </summary>
         public string RoutesToPreCache { get; set; }
 
+        /// <summary>
+        /// The base route to the application.
+        /// </summary>
+        public string BaseRoute { get; set; }
+
         /// <summary>
         /// The route to the page to show when offline.
         /// </summary>

src/ServiceCollectionExtensions.cs

@@ -17,7 +17,6 @@ public static class ServiceCollectionExtensions
         /// </summary>
         public static IServiceCollection AddServiceWorker(this IServiceCollection services)
         {
-
             services.TryAddSingleton<IHttpContextAccessor, HttpContextAccessor>();
             services.AddTransient<ITagHelperComponent, ServiceWorkerTagHelperComponent>();
             services.AddTransient(svc => new PwaOptions(svc.GetRequiredService<IConfiguration>()));
@@ -40,12 +39,13 @@ public static IServiceCollection AddServiceWorker(this IServiceCollection servic
         /// <summary>
         /// Adds ServiceWorker services to the specified <see cref="IServiceCollection"/>.
         /// </summary>
-        public static IServiceCollection AddServiceWorker(this IServiceCollection services, string offlineRoute = Constants.Offlineroute, ServiceWorkerStrategy strategy = ServiceWorkerStrategy.CacheFirstSafe, bool registerServiceWorker = true, bool registerWebManifest = true, string cacheId = Constants.DefaultCacheId, string routesToPreCache = "")
+        public static IServiceCollection AddServiceWorker(this IServiceCollection services, string baseRoute = "", string offlineRoute = Constants.Offlineroute, ServiceWorkerStrategy strategy = ServiceWorkerStrategy.CacheFirstSafe, bool registerServiceWorker = true, bool registerWebManifest = true, string cacheId = Constants.DefaultCacheId, string routesToPreCache = "")
         {
             services.TryAddSingleton<IHttpContextAccessor, HttpContextAccessor>();
             services.AddTransient<ITagHelperComponent, ServiceWorkerTagHelperComponent>();
             services.AddTransient(factory => new PwaOptions
             {
+                BaseRoute = baseRoute,
                 OfflineRoute = offlineRoute,
                 Strategy = strategy,
                 RegisterServiceWorker = registerServiceWorker,

src/ServiceWorker/ServiceWorkerTagHelperComponent.cs

@@ -19,7 +19,7 @@ public ServiceWorkerTagHelperComponent(IHostingEnvironment env, IHttpContextAcce
             _accessor = accessor;
             _options = options;
 
-            _script = "\r\n\t<script" + (_options.EnableCspNonce ? Constants.CspNonce : string.Empty) + ">'serviceWorker'in navigator&&navigator.serviceWorker.register('" + Constants.ServiceworkerRoute + "')</script>";
+            _script = "\r\n\t<script" + (_options.EnableCspNonce ? Constants.CspNonce : string.Empty) + ">'serviceWorker'in navigator&&navigator.serviceWorker.register('" + options.BaseRoute + Constants.ServiceworkerRoute + "')</script>";
         }
 
         /// <inheritdoc />

src/Webmanifest/WebmanifestTagHelperComponent.cs

@@ -5,14 +5,15 @@ namespace WebEssentials.AspNetCore.Pwa
 {
     internal class WebmanifestTagHelperComponent : TagHelperComponent
     {
-        private const string _link = "\t<link rel=\"manifest\" href=\"" + Constants.WebManifestRoute + "\" />\r\n";
+        private string _link;
         private const string _themeFormat = "\t<meta name=\"theme-color\" content=\"{0}\" />\r\n";
         private PwaOptions _options;
         private readonly IServiceProvider _serviceProvider;
 
         public WebmanifestTagHelperComponent(PwaOptions options, IServiceProvider serviceProvider)
         {
             _options = options;
+            _link = "\t<link rel=\"manifest\" href=\"" + options.BaseRoute + Constants.WebManifestRoute + "\" />\r\n";
             _serviceProvider = serviceProvider;
         }