Add proper JSON-fetching example to StandaloneApp

samples/StandaloneApp/Pages/FetchData.cshtml

@@ -1,15 +1,53 @@
 @using Microsoft.AspNetCore.Blazor.Browser.Services.Temporary
 @inject HttpClient Http
 
-<h1>Fetch data</h1>
+<h1>Weather forecast</h1>
 
-<strong>Response: </strong> @responseText
+<p>This component demonstrates fetching data from the server.</p>
+
+@if (forecasts == null)
+{
+    <p><em>Loading...</em></p>
+}
+else
+{
+    <table class='table'>
+        <thead>
+            <tr>
+                <th>Date</th>
+                <th>Temp. (C)</th>
+                <th>Temp. (F)</th>
+                <th>Summary</th>
+            </tr>
+        </thead>
+        <tbody>
+            @foreach (var forecast in forecasts)
+            {
+                <tr>
+                    <td>@forecast.DateFormatted</td>
+                    <td>@forecast.TemperatureC</td>
+                    <td>@forecast.TemperatureF</td>
+                    <td>@forecast.Summary</td>
+                </tr>
+            }
+        </tbody>
+    </table>
+}
 
 @functions {
-    private string responseText;
+    WeatherForecast[] forecasts;
 
     protected override async Task OnInitAsync()
     {
-        responseText = await Http.GetStringAsync("/");
+        var json = await Http.GetStringAsync("/sample-data/weather.json");
+        forecasts = Microsoft.AspNetCore.Blazor.Json.Deserialize<WeatherForecast[]>(json);
+    }
+
+    class WeatherForecast
+    {
+        public string DateFormatted { get; set; }
+        public int TemperatureC { get; set; }
+        public int TemperatureF { get; set; }
+        public string Summary { get; set; }
     }
 }

samples/StandaloneApp/wwwroot/sample-data/weather.json

@@ -0,0 +1,32 @@
+[
+  {
+    "DateFormatted": "06/05/2018",
+    "TemperatureC": 1,
+    "Summary": "Freezing",
+    "TemperatureF": 33
+  },
+  {
+    "DateFormatted": "07/05/2018",
+    "TemperatureC": 14,
+    "Summary": "Bracing",
+    "TemperatureF": 57
+  },
+  {
+    "DateFormatted": "08/05/2018",
+    "TemperatureC": -13,
+    "Summary": "Freezing",
+    "TemperatureF": 9
+  },
+  {
+    "DateFormatted": "09/05/2018",
+    "TemperatureC": -16,
+    "Summary": "Balmy",
+    "TemperatureF": 4
+  },
+  {
+    "DateFormatted": "10/05/2018",
+    "TemperatureC": -2,
+    "Summary": "Chilly",
+    "TemperatureF": 29
+  }
+]

src/Microsoft.AspNetCore.Blazor.Browser/Services/BrowserServiceProvider.cs

@@ -41,8 +41,9 @@ namespace Microsoft.AspNetCore.Blazor.Browser.Services
 
         private void AddDefaultServices(ServiceCollection serviceCollection)
         {
-            serviceCollection.AddSingleton<IUriHelper>(new BrowserUriHelper());
+            var uriHelper = new BrowserUriHelper();
-            serviceCollection.AddSingleton(new HttpClient());
+            serviceCollection.AddSingleton<IUriHelper>(uriHelper);
+            serviceCollection.AddSingleton(new HttpClient(uriHelper));
         }
     }
 }

src/Microsoft.AspNetCore.Blazor.Browser/Services/Temporary/HttpClient.cs

@@ -2,12 +2,12 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using Microsoft.AspNetCore.Blazor.Browser.Interop;
+using Microsoft.AspNetCore.Blazor.Services;
 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Net;
 using System.Net.Http;
-using System.Net.Http.Headers;
 using System.Threading.Tasks;
 
 namespace Microsoft.AspNetCore.Blazor.Browser.Services.Temporary
@@ -25,6 +25,7 @@ namespace Microsoft.AspNetCore.Blazor.Browser.Services.Temporary
         static int _nextRequestId = 0;
         static IDictionary<int, TaskCompletionSource<HttpResponseMessage>> _pendingRequests
             = new Dictionary<int, TaskCompletionSource<HttpResponseMessage>>();
+        IUriHelper _uriHelper;
 
         // Making the constructor internal to be sure people only get instances from
         // the service provider. It doesn't make any difference right now, but when
@@ -33,8 +34,9 @@ namespace Microsoft.AspNetCore.Blazor.Browser.Services.Temporary
         // has to be configured with a browser-specific HTTP handler. In the long
         // term, it should be possible to use System.Net.Http.HttpClient directly
         // without any browser-specific constructor args.
-        internal HttpClient()
+        internal HttpClient(IUriHelper uriHelper)
         {
+            _uriHelper = uriHelper ?? throw new ArgumentNullException(nameof(uriHelper));
         }
 
         /// <summary>
@@ -61,7 +63,7 @@ namespace Microsoft.AspNetCore.Blazor.Browser.Services.Temporary
         /// <param name="requestUri">The URI the request is sent to.</param>
         /// <returns>A task representing the asynchronous operation.</returns>
         public Task<HttpResponseMessage> GetAsync(string requestUri)
-            => SendAsync(new HttpRequestMessage(HttpMethod.Get, requestUri));
+            => SendAsync(new HttpRequestMessage(HttpMethod.Get, CreateUri(requestUri)));
 
         /// <summary>
         /// Sends a POST request to the specified URI and returns the response as
@@ -72,7 +74,7 @@ namespace Microsoft.AspNetCore.Blazor.Browser.Services.Temporary
         /// <param name="content">The content for the request.</param>
         /// <returns>A task representing the asynchronous operation.</returns>
         public Task<HttpResponseMessage> PostAsync(string requestUri, HttpContent content)
-            => SendAsync(new HttpRequestMessage(HttpMethod.Post, requestUri)
+            => SendAsync(new HttpRequestMessage(HttpMethod.Post, CreateUri(requestUri))
             {
                 Content = content
             });
@@ -98,7 +100,7 @@ namespace Microsoft.AspNetCore.Blazor.Browser.Services.Temporary
                 $"{typeof(HttpClient).FullName}.Send",
                 id,
                 request.Method.Method,
-                request.RequestUri.ToString(),
+                ResolveRequestUri(request.RequestUri),
                 request.Content == null ? null : await GetContentAsString(request.Content),
                 SerializeHeadersAsJson(request));
 
@@ -119,6 +121,9 @@ namespace Microsoft.AspNetCore.Blazor.Browser.Services.Temporary
                     $"only supports contents of type {nameof(StringContent)}, but you supplied " +
                     $"{content.GetType().FullName}.");
 
+        private Uri CreateUri(String uri)
+            => new Uri(uri, UriKind.RelativeOrAbsolute);
+
         private static void ReceiveResponse(
             string id,
             string responseDescriptorJson,
@@ -146,6 +151,9 @@ namespace Microsoft.AspNetCore.Blazor.Browser.Services.Temporary
             }
         }
 
+        private string ResolveRequestUri(Uri requestUri)
+            => _uriHelper.ToAbsoluteUri(requestUri.OriginalString).AbsoluteUri;
+
         // Keep in sync with TypeScript class in Http.ts
         private class ResponseDescriptor
         {