Further refined IPaginator, making it possible to do search pagination!

SpotifyAPI.Web/Clients/Interfaces/IPaginator.cs

@@ -9,5 +9,8 @@ namespace SpotifyAPI.Web
   {
     Task<List<T>> Paginate<T>(Paging<T> firstPage, IAPIConnector connector);
     Task<List<T>> Paginate<T>(Func<Task<Paging<T>>> getFirstPage, IAPIConnector connector);
+
+    Task<List<T>> Paginate<T, TNext>(Paging<T, TNext> firstPage, Func<TNext, Paging<T, TNext>> mapper, IAPIConnector connector);
+    Task<List<T>> Paginate<T, TNext>(Func<Task<Paging<T, TNext>>> getFirstPage, Func<TNext, Paging<T, TNext>> mapper, IAPIConnector connector);
   }
 }

SpotifyAPI.Web/Clients/Interfaces/ISpotifyClient.cs

@@ -23,7 +23,9 @@ namespace SpotifyAPI.Web
     ITracksClient Tracks { get; }
 
     Task<List<T>> Paginate<T>(Paging<T> firstPage);
+    Task<List<T>> Paginate<T, TNext>(Paging<T, TNext> firstPage, Func<TNext, Paging<T, TNext>> mapper);
     Task<List<T>> Paginate<T>(Func<Task<Paging<T>>> getFirstPage);
+    Task<List<T>> Paginate<T, TNext>(Func<Task<Paging<T, TNext>>> getFirstPage, Func<TNext, Paging<T, TNext>> mapper);
     Task<List<T>> Paginate<T>(Paging<T> firstPage, IPaginator paginator);
     Task<List<T>> Paginate<T>(Func<Task<Paging<T>>> getFirstPage, IPaginator paginator);
   }

SpotifyAPI.Web/Clients/SimplePaginator.cs

@@ -7,9 +7,13 @@ namespace SpotifyAPI.Web
 {
   public class SimplePaginator : IPaginator
   {
-    protected virtual bool ShouldContinue<T>(List<T> results, Paging<T> page)
+    protected virtual Task<bool> ShouldContinue<T>(List<T> results, Paging<T> page)
     {
-      return true;
+      return Task.FromResult(true);
+    }
+    protected virtual Task<bool> ShouldContinue<T, TNext>(List<T> results, Paging<T, TNext> page)
+    {
+      return Task.FromResult(true);
     }
 
     public async Task<List<T>> Paginate<T>(Paging<T> firstPage, IAPIConnector connector)
@@ -20,7 +24,7 @@ namespace SpotifyAPI.Web
       var page = firstPage;
       var results = new List<T>();
       results.AddRange(firstPage.Items);
-      while (page.Next != null && ShouldContinue(results, page))
+      while (page.Next != null && await ShouldContinue(results, page).ConfigureAwait(false))
       {
         page = await connector.Get<Paging<T>>(new Uri(page.Next, UriKind.Absolute)).ConfigureAwait(false);
         results.AddRange(page.Items);
@@ -36,5 +40,34 @@ namespace SpotifyAPI.Web
       var firstPage = await getFirstPage().ConfigureAwait(false);
       return await Paginate(firstPage, connector).ConfigureAwait(false);
     }
+
+    public async Task<List<T>> Paginate<T, TNext>(
+      Paging<T, TNext> firstPage, Func<TNext, Paging<T, TNext>> mapper, IAPIConnector connector
+    )
+    {
+      Ensure.ArgumentNotNull(firstPage, nameof(firstPage));
+      Ensure.ArgumentNotNull(mapper, nameof(mapper));
+      Ensure.ArgumentNotNull(connector, nameof(connector));
+
+      var page = firstPage;
+      var results = new List<T>();
+      results.AddRange(firstPage.Items);
+      while (page.Next != null && await ShouldContinue(results, page).ConfigureAwait(false))
+      {
+        var next = await connector.Get<TNext>(new Uri(page.Next, UriKind.Absolute)).ConfigureAwait(false);
+        page = mapper(next);
+        results.AddRange(page.Items);
+      }
+
+      return results;
+    }
+
+    public async Task<List<T>> Paginate<T, TNext>(Func<Task<Paging<T, TNext>>> getFirstPage, Func<TNext, Paging<T, TNext>> mapper, IAPIConnector connector)
+    {
+      Ensure.ArgumentNotNull(getFirstPage, nameof(getFirstPage));
+
+      var firstPage = await getFirstPage().ConfigureAwait(false);
+      return await Paginate(firstPage, mapper, connector).ConfigureAwait(false);
+    }
   }
 }

SpotifyAPI.Web/Clients/SpotifyClient.cs

@@ -49,6 +49,11 @@ namespace SpotifyAPI.Web
       return DefaultPaginator.Paginate(firstPage, _apiConnector);
     }
 
+    public Task<List<T>> Paginate<T, TNext>(Paging<T, TNext> firstPage, Func<TNext, Paging<T, TNext>> mapper)
+    {
+      return DefaultPaginator.Paginate(firstPage, mapper, _apiConnector);
+    }
+
     public Task<List<T>> Paginate<T>(Paging<T> firstPage, IPaginator paginator)
     {
       Ensure.ArgumentNotNull(paginator, nameof(paginator));
@@ -61,6 +66,11 @@ namespace SpotifyAPI.Web
       return DefaultPaginator.Paginate(getFirstPage, _apiConnector);
     }
 
+    public Task<List<T>> Paginate<T, TNext>(Func<Task<Paging<T, TNext>>> getFirstPage, Func<TNext, Paging<T, TNext>> mapper)
+    {
+      return DefaultPaginator.Paginate(getFirstPage, mapper, _apiConnector);
+    }
+
     public Task<List<T>> Paginate<T>(Func<Task<Paging<T>>> getFirstPage, IPaginator paginator)
     {
       Ensure.ArgumentNotNull(paginator, nameof(paginator));

SpotifyAPI.Web/Http/APIConnector.cs

@@ -158,7 +158,7 @@ namespace SpotifyAPI.Web.Http
       Ensure.ArgumentNotNull(uri, nameof(uri));
       Ensure.ArgumentNotNull(method, nameof(method));
 
-      return new Request(parameters)
+      return new Request(new Dictionary<string, string>(), parameters)
       {
         BaseAddress = _baseAddress,
         Endpoint = uri,

SpotifyAPI.Web/Models/Response/Paging.cs

@@ -12,4 +12,15 @@ namespace SpotifyAPI.Web
     public string Previous { get; private set; }
     public int Total { get; private set; }
   }
+
+  public class Paging<T, TNext>
+  {
+    public string Href { get; private set; }
+    public List<T> Items { get; private set; }
+    public int Limit { get; private set; }
+    public string Next { get; private set; }
+    public int Offset { get; private set; }
+    public string Previous { get; private set; }
+    public int Total { get; private set; }
+  }
 }

SpotifyAPI.Web/Models/Response/SearchResponse.cs

@@ -2,10 +2,10 @@ namespace SpotifyAPI.Web
 {
   public class SearchResponse
   {
-    public Paging<FullArtist> Artists { get; private set; }
+    public Paging<FullArtist, SearchResponse> Artists { get; private set; }
-    public Paging<SimpleAlbum> Albums { get; private set; }
+    public Paging<SimpleAlbum, SearchResponse> Albums { get; private set; }
-    public Paging<FullTrack> Tracks { get; private set; }
+    public Paging<FullTrack, SearchResponse> Tracks { get; private set; }
-    public Paging<SimpleShow> Shows { get; private set; }
+    public Paging<SimpleShow, SearchResponse> Shows { get; private set; }
-    public Paging<SimpleEpisode> Episodes { get; private set; }
+    public Paging<SimpleEpisode, SearchResponse> Episodes { get; private set; }
   }
 }