From 323561909e0cbcc241eed992295135bff3f89661 Mon Sep 17 00:00:00 2001
From: "Johnny @PC" <johnny@johnnycrazy.de>
Date: Sat, 7 Nov 2015 20:18:39 +0100
Subject: [PATCH] Added HasNextPage and HasPreviousPage to Paging-Objects.
 Renamed Next and Previous to GetNextPage and GetPreviousPage

---
 SpotifyAPI/Web/Models/Paging.cs | 10 ++++++++++
 SpotifyAPI/Web/SpotifyWebAPI.cs | 24 +++++++++++++++++++++---
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/SpotifyAPI/Web/Models/Paging.cs b/SpotifyAPI/Web/Models/Paging.cs
index d40a426e..6c37b323 100644
--- a/SpotifyAPI/Web/Models/Paging.cs
+++ b/SpotifyAPI/Web/Models/Paging.cs
@@ -26,5 +26,15 @@ namespace SpotifyAPI.Web.Models
 
         [JsonProperty("total")]
         public int Total { get; set; }
+
+        public bool HasNextPage()
+        {
+            return Next != null;
+        }
+
+        public bool HasPreviousPage()
+        {
+            return Next != null;
+        }
     }
 }
\ No newline at end of file
diff --git a/SpotifyAPI/Web/SpotifyWebAPI.cs b/SpotifyAPI/Web/SpotifyWebAPI.cs
index 56dcc025..77dc8fa4 100644
--- a/SpotifyAPI/Web/SpotifyWebAPI.cs
+++ b/SpotifyAPI/Web/SpotifyWebAPI.cs
@@ -40,7 +40,7 @@ namespace SpotifyAPI.Web
         public void Dispose()
         {
             WebClient.Dispose();
-            GC.SuppressFinalize(this); //TODO
+            GC.SuppressFinalize(this);
         }
 
         #region Search
@@ -1450,16 +1450,34 @@ namespace SpotifyAPI.Web
 
         #region Util
 
-        public Paging<T> Next<T>(Paging<T> paging)
+        public Paging<T> GetNextPage<T>(Paging<T> paging)
         {
+            if (!paging.HasNextPage())
+                throw new InvalidOperationException("This Paging-Object has no Next-Page");
             return DownloadData<Paging<T>>(paging.Next);
         }
 
-        public Paging<T> Previous<T>(Paging<T> paging)
+        public async Task<Paging<T>> GetNextPageAsync<T>(Paging<T> paging)
         {
+            if (!paging.HasNextPage())
+                throw new InvalidOperationException("This Paging-Object has no Next-Page");
+            return await DownloadDataAsync<Paging<T>>(paging.Next);
+        }
+
+        public Paging<T> GetPreviousPage<T>(Paging<T> paging)
+        {
+            if (!paging.HasPreviousPage())
+                throw new InvalidOperationException("This Paging-Object has no Previous-Page");
             return DownloadData<Paging<T>>(paging.Previous);
         }
 
+        public async Task<Paging<T>> GetPreviousPageAsync<T>(Paging<T> paging)
+        {
+            if (!paging.HasPreviousPage())
+                throw new InvalidOperationException("This Paging-Object has no Previous-Page");
+            return await DownloadDataAsync<Paging<T>>(paging.Previous);
+        }
+
         public T UploadData<T>(String url, String uploadData, String method = "POST")
         {
             if (!UseAuth)