#218 - Refactor query string parsing into a service class.

maraf · Mar 7, 2019 · d384a02 · d384a02
1 parent b399d7a
commit d384a02
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Showing 5 changed files with 104 additions and 26 deletions.
diff --git a/src/Money.UI.Blazor/Pages/Account/Login.cshtml.cs b/src/Money.UI.Blazor/Pages/Account/Login.cshtml.cs
@@ -1,6 +1,7 @@
 using Microsoft.AspNetCore.Blazor.Components;
 using Microsoft.AspNetCore.Blazor.Services;
 using Money.Services;
+using Neptuo.Collections.Specialized;
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -18,7 +19,7 @@ public class LoginBase : BlazorComponent
         internal ApiClient ApiClient { get; set; }
 
         [Inject]
-        internal IUriHelper Uri { get; set; }
+        internal QueryString QueryString { get; set; }
 
         [Parameter]
         protected string ReturnUrl { get; set; }
@@ -32,29 +33,7 @@ public class LoginBase : BlazorComponent
         protected override void OnParametersSet()
         {
             base.OnParametersSet();
-            SetReturnUrl();
-        }
-
-        private void SetReturnUrl()
-        {
-            string url = Uri.GetAbsoluteUri();
-            int indexOfQuery = url.IndexOf('?');
-            if (indexOfQuery >= 0)
-            {
-                string query = url.Substring(indexOfQuery + 1).ToLowerInvariant();
-                string[] parameters = query.Split('&');
-                foreach (string parameter in parameters)
-                {
-                    string[] keyValue = parameter.Split('=');
-                    if (keyValue[0] == "returnurl")
-                    {
-                        if (keyValue.Length == 2)
-                            ReturnUrl = keyValue[1];
-
-                        break;
-                    }
-                }
-            }
+            ReturnUrl = QueryString.Find<string>("returnUrl");
         }
 
         protected Task OnSubmitAsync()
@@ -71,8 +50,8 @@ private async Task LoginAsync(string userName, string password, bool isPermanent
             {
                 if (!await ApiClient.LoginAsync(userName, password, isPermanent))
                     ErrorMessages.Add("User name and password don't match.");
-                else if (ReturnUrl != null)
-                    Uri.NavigateTo(ReturnUrl);
+                else if (!String.IsNullOrEmpty(ReturnUrl))
+                    Navigator.Open(ReturnUrl);
                 else
                     Navigator.OpenSummary();
             }

diff --git a/src/Money.UI.Blazor/Services/Navigator.cs b/src/Money.UI.Blazor/Services/Navigator.cs
@@ -36,6 +36,9 @@ private void OnLocationChanged(object sender, string e)
         private void OpenExternal(string url)
             => Interop.NavigateTo(url);
 
+        public void Open(string url)
+            => uri.NavigateTo(url);
+
         public void OpenSummary()
             => uri.NavigateTo(UrlSummary());
 

diff --git a/src/Money.UI.Blazor/Services/QueryString.cs b/src/Money.UI.Blazor/Services/QueryString.cs
@@ -0,0 +1,76 @@
+using Microsoft.AspNetCore.Blazor.Services;
+using Neptuo;
+using Neptuo.Collections.Specialized;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Money.Services
+{
+    /// <summary>
+    /// A current parsed query string provider.
+    /// </summary>
+    public class QueryString : DisposableBase, IReadOnlyKeyValueCollection
+    {
+        private readonly IUriHelper uri;
+        private KeyValueCollection parameters;
+
+        public QueryString(IUriHelper uri)
+        {
+            Ensure.NotNull(uri, "uri");
+            this.uri = uri;
+
+            uri.OnLocationChanged += OnLocationChanged;
+        }
+
+        private void OnLocationChanged(object sender, string e)
+            => parameters = null;
+
+        private void EnsureParameters()
+        {
+            if (parameters == null)
+            {
+                parameters = new KeyValueCollection();
+
+                string url = uri.GetAbsoluteUri();
+                int indexOfQuery = url.IndexOf('?');
+                if (indexOfQuery >= 0)
+                {
+                    string query = url.Substring(indexOfQuery + 1).ToLowerInvariant();
+                    string[] items = query.Split('&');
+                    foreach (string parameter in items)
+                    {
+                        string[] keyValue = parameter.Split('=');
+                        if (keyValue.Length == 2)
+                            parameters.Add(keyValue[0], keyValue[1]);
+                        else
+                            parameters.Add(keyValue[0], null);
+                    }
+                }
+            }
+        }
+
+        public IEnumerable<string> Keys
+        {
+            get
+            {
+                EnsureParameters();
+                return parameters.Keys;
+            }
+        }
+
+        public bool TryGet<T>(string key, out T value)
+        {
+            EnsureParameters();
+            return parameters.TryGet(key?.ToLowerInvariant(), out value);
+        }
+
+        protected override void DisposeManagedResources()
+        {
+            base.DisposeManagedResources();
+            uri.OnLocationChanged -= OnLocationChanged;
+        }
+    }
+}
diff --git a/src/Money.UI.Blazor/Startup.cs b/src/Money.UI.Blazor/Startup.cs
@@ -20,6 +20,7 @@ public void ConfigureServices(IServiceCollection services)
             services
                 .AddTransient<Navigator>()
                 .AddTransient<ApiClient>()
+                .AddSingleton<QueryString>()
                 .AddSingleton<CommandMapper>()
                 .AddSingleton<QueryMapper>()
                 .AddSingleton<ColorCollection>()

diff --git a/src/Neptuo/Collections/Specialized/_ReadOnlyKeyValueCollectionExtensions.cs b/src/Neptuo/Collections/Specialized/_ReadOnlyKeyValueCollectionExtensions.cs
@@ -51,6 +51,25 @@ public static T Get<T>(this IReadOnlyKeyValueCollection collection, string key,
             return defaultValue;
         }
 
+        /// <summary>
+        /// Reads the value of <paramref name="key"/> in <paramref name="collection"/>.
+        /// If value is found and can be converted to <typeparamref name="T"/>, returns it.
+        /// Otherwise the default value of <typeparamref name="T"/> is returned.
+        /// </summary>
+        /// <param name="collection">Collection of key-value pairs.</param>
+        /// <param name="key">Requested key.</param>
+        /// <returns>Value of <paramref name="key"/> in <paramref name="collection"/>.</returns>
+        public static T Find<T>(this IReadOnlyKeyValueCollection collection, string key)
+        {
+            Ensure.NotNull(collection, "collection");
+
+            T value;
+            if (collection.TryGet(key, out value))
+                return value;
+
+            return default(T);
+        }
+
         /// <summary>
         /// Returns <c>true</c> if <paramref name="collection"/> contains <paramref name="key"/>.
         /// </summary>