Move WebSearch to Async model

Plugins/Flow.Launcher.Plugin.WebSearch/Main.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
+using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
 using System.Windows.Controls;
@@ -13,14 +14,12 @@ using Flow.Launcher.Plugin.SharedCommands;
 
 namespace Flow.Launcher.Plugin.WebSearch
 {
-    public class Main : IPlugin, ISettingProvider, IPluginI18n, ISavable, IResultUpdated
+    public class Main : IAsyncPlugin, ISettingProvider, IPluginI18n, ISavable, IResultUpdated
     {
         private PluginInitContext _context;
 
         private readonly Settings _settings;
         private readonly SettingsViewModel _viewModel;
-        private CancellationTokenSource _updateSource;
-        private CancellationToken _updateToken;
 
         internal const string Images = "Images";
         internal static string DefaultImagesDirectory;
@@ -33,7 +32,7 @@ namespace Flow.Launcher.Plugin.WebSearch
             _viewModel.Save();
         }
 
-        public List<Result> Query(Query query)
+        public async Task<List<Result>> QueryAsync(Query query, CancellationToken token)
         {
             if (FilesFolders.IsLocationPathString(query.Search))
                 return new List<Result>();
@@ -41,10 +40,6 @@ namespace Flow.Launcher.Plugin.WebSearch
             var searchSourceList = new List<SearchSource>();
             var results = new List<Result>();
 
-            _updateSource?.Cancel();
-            _updateSource = new CancellationTokenSource();
-            _updateToken = _updateSource.Token;
-            
             _settings.SearchSources.Where(o => (o.ActionKeyword == query.ActionKeyword || o.ActionKeyword == SearchSourceGlobalPluginWildCardSign)
                                                && o.Enabled)
                                     .ToList()
@@ -94,49 +89,45 @@ namespace Flow.Launcher.Plugin.WebSearch
                         };
 
                         results.Add(result);
-                        ResultsUpdated?.Invoke(this, new ResultUpdatedEventArgs
-                        {
-                            Results = results,
-                            Query = query
-                        });
-
-                        UpdateResultsFromSuggestion(results, keyword, subtitle, searchSource, query);                        
                     }
+
+                    ResultsUpdated?.Invoke(this, new ResultUpdatedEventArgs
+                    {
+                        Results = results,
+                        Query = query
+                    });
+
+                    await UpdateResultsFromSuggestionAsync(results, keyword, subtitle, searchSource, query, token).ConfigureAwait(false);
                 }
             }
 
             return results;
         }
 
-        private void UpdateResultsFromSuggestion(List<Result> results, string keyword, string subtitle,
+        private async Task UpdateResultsFromSuggestionAsync(List<Result> results, string keyword, string subtitle,
-            SearchSource searchSource, Query query)
+            SearchSource searchSource, Query query, CancellationToken token)
         {
             if (_settings.EnableSuggestion)
             {
-                const int waittime = 300;
+                var suggestions = await SuggestionsAsync(keyword, subtitle, searchSource, token).ConfigureAwait(false);
-                var task = Task.Run(async () =>
+                results.AddRange(suggestions);
-                {
-                    var suggestions = await Suggestions(keyword, subtitle, searchSource);
-                    results.AddRange(suggestions);
-                }, _updateToken);
 
-                if (!task.Wait(waittime))
+                token.ThrowIfCancellationRequested();
+
+                ResultsUpdated?.Invoke(this, new ResultUpdatedEventArgs
                 {
-                    task.ContinueWith(_ => ResultsUpdated?.Invoke(this, new ResultUpdatedEventArgs
+                    Results = results,
-                    {
+                    Query = query
-                        Results = results,
+                });
-                        Query = query
-                    }), _updateToken);
-                }
             }
         }
 
-        private async Task<IEnumerable<Result>> Suggestions(string keyword, string subtitle, SearchSource searchSource)
+        private async Task<IEnumerable<Result>> SuggestionsAsync(string keyword, string subtitle, SearchSource searchSource, CancellationToken token)
         {
             var source = _settings.SelectedSuggestion;
             if (source != null)
             {
-                var suggestions = await source.Suggestions(keyword);
+                var suggestions = await source.Suggestions(keyword, token);
                 var resultsFromSuggestion = suggestions.Select(o => new Result
                 {
                     Title = o,
@@ -169,19 +160,24 @@ namespace Flow.Launcher.Plugin.WebSearch
             _settings = _viewModel.Settings;
         }
 
-        public void Init(PluginInitContext context)
+        public Task InitAsync(PluginInitContext context)
         {
-            _context = context;
+            return Task.Run(Init);
-            var pluginDirectory = _context.CurrentPluginMetadata.PluginDirectory;
-            var bundledImagesDirectory = Path.Combine(pluginDirectory, Images);
 
-            // Default images directory is in the WebSearch's application folder  
+            void Init()
-            DefaultImagesDirectory = Path.Combine(pluginDirectory, Images);
+            {
-            Helper.ValidateDataDirectory(bundledImagesDirectory, DefaultImagesDirectory);
+                _context = context;
+                var pluginDirectory = _context.CurrentPluginMetadata.PluginDirectory;
+                var bundledImagesDirectory = Path.Combine(pluginDirectory, Images);
 
-            // Custom images directory is in the WebSearch's data location folder 
+                // Default images directory is in the WebSearch's application folder  
-            var name = Path.GetFileNameWithoutExtension(_context.CurrentPluginMetadata.ExecuteFileName);
+                DefaultImagesDirectory = Path.Combine(pluginDirectory, Images);
-            CustomImagesDirectory = Path.Combine(DataLocation.PluginSettingsDirectory, name, "CustomIcons");
+                Helper.ValidateDataDirectory(bundledImagesDirectory, DefaultImagesDirectory);
+
+                // Custom images directory is in the WebSearch's data location folder 
+                var name = Path.GetFileNameWithoutExtension(_context.CurrentPluginMetadata.ExecuteFileName);
+                CustomImagesDirectory = Path.Combine(DataLocation.PluginSettingsDirectory, name, "CustomIcons");
+            };
         }
 
         #region ISettingProvider Members

Plugins/Flow.Launcher.Plugin.WebSearch/SuggestionSources/Baidu.cs

@@ -9,6 +9,7 @@ using Newtonsoft.Json.Linq;
 using Flow.Launcher.Infrastructure.Http;
 using Flow.Launcher.Infrastructure.Logger;
 using System.Net.Http;
+using System.Threading;
 
 namespace Flow.Launcher.Plugin.WebSearch.SuggestionSources
 {
@@ -16,14 +17,14 @@ namespace Flow.Launcher.Plugin.WebSearch.SuggestionSources
     {
         private readonly Regex _reg = new Regex("window.baidu.sug\\((.*)\\)");
 
-        public override async Task<List<string>> Suggestions(string query)
+        public override async Task<List<string>> Suggestions(string query, CancellationToken token)
         {
             string result;
 
             try
             {
                 const string api = "http://suggestion.baidu.com/su?json=1&wd=";
-                result = await Http.GetAsync(api + Uri.EscapeUriString(query)).ConfigureAwait(false);
+                result = await Http.GetAsync(api + Uri.EscapeUriString(query), token).ConfigureAwait(false);
             }
             catch (HttpRequestException e)
             {

Plugins/Flow.Launcher.Plugin.WebSearch/SuggestionSources/Bing.cs

@@ -9,19 +9,20 @@ using System.Text.RegularExpressions;
 using System.Threading.Tasks;
 using System.Text.Json;
 using System.Linq;
+using System.Threading;
 
 namespace Flow.Launcher.Plugin.WebSearch.SuggestionSources
 {
     class Bing : SuggestionSource
     {
-        public override async Task<List<string>> Suggestions(string query)
+        public override async Task<List<string>> Suggestions(string query, CancellationToken token)
         {
             Stream resultStream;
 
             try
             {
                 const string api = "https://api.bing.com/qsonhs.aspx?q=";
-                resultStream = await Http.GetStreamAsync(api + Uri.EscapeUriString(query)).ConfigureAwait(false);
+                resultStream = await Http.GetStreamAsync(api + Uri.EscapeUriString(query), token).ConfigureAwait(false);
             }
             catch (HttpRequestException e)
             {
@@ -29,7 +30,7 @@ namespace Flow.Launcher.Plugin.WebSearch.SuggestionSources
                 return new List<string>();
             }
 
-            if (resultStream.Length == 0) return new List<string>();
+            if (resultStream.Length == 0) return new List<string>(); // this handles the cancellation
 
             JsonElement json;
             try

Plugins/Flow.Launcher.Plugin.WebSearch/SuggestionSources/Google.cs

@@ -8,18 +8,19 @@ using Newtonsoft.Json.Linq;
 using Flow.Launcher.Infrastructure.Http;
 using Flow.Launcher.Infrastructure.Logger;
 using System.Net.Http;
+using System.Threading;
 
 namespace Flow.Launcher.Plugin.WebSearch.SuggestionSources
 {
     public class Google : SuggestionSource
     {
-        public override async Task<List<string>> Suggestions(string query)
+        public override async Task<List<string>> Suggestions(string query, CancellationToken token)
         {
             string result;
             try
             {
                 const string api = "https://www.google.com/complete/search?output=chrome&q=";
-                result = await Http.GetAsync(api + Uri.EscapeUriString(query)).ConfigureAwait(false);
+                result = await Http.GetAsync(api + Uri.EscapeUriString(query), token).ConfigureAwait(false);
             }
             catch (HttpRequestException e)
             {

Plugins/Flow.Launcher.Plugin.WebSearch/SuggestionSources/SuggestionSource.cs

@@ -1,10 +1,11 @@
 using System.Collections.Generic;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Flow.Launcher.Plugin.WebSearch.SuggestionSources
 {
     public abstract class SuggestionSource
     {
-        public abstract Task<List<string>> Suggestions(string query);
+        public abstract Task<List<string>> Suggestions(string query, CancellationToken token);
     }
 }