closes #456.

modules/docs/src/Volo.Docs.Application.Contracts/Volo/Docs/Documents/ContentWithDetailsDto.cs

@@ -27,6 +27,8 @@ namespace Volo.Docs.Documents
         public string FileName { get; set; }
 
         public ProjectDto Project { get; set; }
+
+        public bool SuccessfullyRetrieved { get; set; }
     }
 
     public class NavigationNode

modules/docs/src/Volo.Docs.Application/Volo/Docs/Documents/Document.cs

@@ -19,5 +19,7 @@ namespace Volo.Docs.Documents
         public string LocalDirectory { get; set; }
 
         public string FileName { get; set; }
+
+        public bool SuccessfullyRetrieved { get; set; }
     }
 }

modules/docs/src/Volo.Docs.Application/Volo/Docs/Documents/GithubDocumentStore.cs

@@ -8,6 +8,7 @@ using System.Net.Sockets;
 using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
 using Octokit;
+using Volo.Abp;
 using Volo.Abp.Domain.Services;
 using ProductHeaderValue = Octokit.ProductHeaderValue;
 
@@ -17,7 +18,7 @@ namespace Volo.Docs.Documents
     {
         public const string Type = "Github"; //TODO: Convert to "github"
 
-        private const bool IsOffline = true; //use it when you don't want to get from GitHub (eg: I have no internet)
+        public const int DocumentNotFoundExceptionCode = 20181001;
 
         public async Task<Document> FindDocumentByNameAsync(Dictionary<string, object> projectExtraProperties, string projectFormat, string documentName, string version)
         {
@@ -38,62 +39,37 @@ namespace Volo.Docs.Documents
                     documentName.Length - documentName.LastIndexOf('/') - 1);
             }
 
-            var content = DownloadWebContent(documentName, rawUrl);
-
-            return await Task.FromResult(new Document
+            var document = new Document
             {
                 Title = documentName,
-                Content = content,
                 EditLink = editLink,
                 RootUrl = rootUrl,
                 RawRootUrl = rawRootUrl,
                 Format = projectFormat,
                 LocalDirectory = localDirectory,
                 FileName = fileName,
-                Version = version
-            });
+                Version = version,
+                SuccessfullyRetrieved = TryDownloadWebContent(rawUrl, out var content),
+                Content = content
+            };
+
+            return await Task.FromResult(document);
         }
 
-        private string DownloadWebContent(string documentName, string rawUrl)
+        private bool TryDownloadWebContent(string rawUrl, out string content)
         {
             using (var webClient = new WebClient())
             {
                 try
                 {
-                    return webClient.DownloadString(rawUrl);
-                }
-                catch (WebException ex)
-                {
-                    Logger.LogError(ex, ex.Message);
-
-                    if (ex.Status == WebExceptionStatus.ProtocolError)
-                    {
-                        if (ex.Response != null && ex.Response is HttpWebResponse response)
-                        {
-                            if (response.StatusCode == HttpStatusCode.NotFound)
-                            {
-                                return $"The document {documentName} not found in this version!";
-                            }
-                        }
-                    }
-                    //todo: remove it when filedocumentstore is implemented
-                    else if (ex.InnerException is HttpRequestException &&
-                             ex.InnerException.InnerException != null &&
-                             ex.InnerException.InnerException is SocketException exception &&
-                             exception.SocketErrorCode == SocketError.HostNotFound)
-                    {
-                        if (IsOffline)
-                        {
-                            return File.ReadAllText(Path.Combine(@"D:\Github\abp\docs\", documentName));
-                        }
-                    }
-
-                    return "An error occured while getting the document " + documentName;
+                    content = webClient.DownloadString(rawUrl);
+                    return true;
                 }
                 catch (Exception ex)
                 {
+                    content = null;
                     Logger.LogError(ex, ex.Message);
-                    return "An error occured while getting the document " + documentName;
+                    return false;
                 }
             }
         }

modules/docs/src/Volo.Docs.Domain/Volo/Docs/Localization/Domain/en.json

@@ -8,6 +8,7 @@
     "InThisDocument": "In this document",
     "GoToTop": "Go to top",
     "Projects": "Project(s)",
-    "NoProjectWarning": "There are no projects yet!"
+    "NoProjectWarning": "There are no projects yet!",
+    "DocumentNotFound": "Oops, the requested document was not found!"
   }
 }

modules/docs/src/Volo.Docs.Domain/Volo/Docs/Localization/Domain/tr.json

@@ -8,6 +8,7 @@
     "InThisDocument": "Bu dökümanda",
     "GoToTop": "En üste çık",
     "Projects": "Proje(ler)",
-    "NoProjectWarning": "Hiç proje yok!"
+    "NoProjectWarning": "Hiç proje yok!",
+    "DocumentNotFound": "Aradığınız döküman bulunamadı!"
   }
 }

modules/docs/src/Volo.Docs.Web/Formatting/MarkdownDocumentConverter.cs

@@ -16,12 +16,17 @@ namespace Volo.Docs.Formatting
 
         public string Convert(string content)
         {
-            return CommonMarkConverter.Convert(Encoding.UTF8.GetString(Encoding.Default.GetBytes(content)));
+            return content == null ? null : CommonMarkConverter.Convert(Encoding.UTF8.GetString(Encoding.Default.GetBytes(content)));
         }
 
         public string NormalizeLinks(string content, string projectShortName, string version,
             string documentLocalDirectory)
         {
+            if (content == null)
+            {
+                return null;
+            }
+
             return Regex.Replace(content, MarkdownLinkRegExp, delegate (Match match)
                 {
                     var displayText = match.Groups[1].Value;
@@ -33,6 +38,11 @@ namespace Volo.Docs.Formatting
 
         private static string RemoveFileExtensionIfLocalUrl(string documentName)
         {
+            if (documentName == null)
+            {
+                return null;
+            }
+
             if (string.IsNullOrWhiteSpace(documentName))
             {
                 return documentName;
@@ -53,6 +63,11 @@ namespace Volo.Docs.Formatting
 
         private static bool IsRemoteUrl(string url)
         {
+            if (url == null)
+            {
+                return true;
+            }
+
             try
             {
                 return Regex.IsMatch(url, @"\A(https?|ftp)://(-\.)?([^\s/?\.#-]+\.?)+(/[^\s]*)?\z");

modules/docs/src/Volo.Docs.Web/Pages/Documents/Project/HtmlNormalizer.cs

@@ -7,6 +7,11 @@ namespace Volo.Docs.Pages.Documents.Project
     {
         public static string ReplaceImageSources(string content, string documentRawRootUrl, string localDirectory)
         {
+            if (content == null)
+            {
+                return null;
+            }
+
             content = Regex.Replace(content, @"(<img\s+[^>]*)src=""([^""]*)""([^>]*>)", delegate (Match match)
                 {
                     var newImageSource = documentRawRootUrl.EnsureEndsWith('/') +
@@ -22,7 +27,7 @@ namespace Volo.Docs.Pages.Documents.Project
 
         public static string ReplaceCodeBlocksLanguage(string content, string currentLanguage, string newLanguage)
         {
-            return content.Replace("<code class=\"" + currentLanguage + "\">", "<code class=\"" + newLanguage + "\">");
+            return content?.Replace("<code class=\"" + currentLanguage + "\">", "<code class=\"" + newLanguage + "\">");
         }
 
     }

modules/docs/src/Volo.Docs.Web/Pages/Documents/Project/Index.cshtml

@@ -109,41 +109,54 @@
             </div>
         </div>
 
-        <div class="col-md-7 docs-content bg-white">
+        @if (Model.Document.SuccessfullyRetrieved)
+        {
 
-            <div class="docs-link-btns">
-                @if (!string.IsNullOrEmpty(Model.Document.EditLink))
-                {
-                    <a href="@Model.Document.EditLink" target="_blank"> <i class="fa fa-edit"></i> @L["Edit"]</a>
-                }
-            </div>
+            <div class="col-md-7 docs-content bg-white">
+
+                <div class="docs-link-btns">
+                    @if (!string.IsNullOrEmpty(Model.Document.EditLink))
+                    {
+                        <a href="@Model.Document.EditLink" target="_blank"> <i class="fa fa-edit"></i> @L["Edit"]</a>
+                    }
+                </div>
 
-            <div class="docs-content-field">
-                <div class="docs-text-field">
-                    <div data-spy="scroll" data-target="#docs-sticky-index" data-offset="0">
-                        <article class="docs-body">
-                            @Html.Raw(Model.Document.Content)
-                        </article>
+                <div class="docs-content-field">
+                    <div class="docs-text-field">
+                        <div data-spy="scroll" data-target="#docs-sticky-index" data-offset="0">
+                            <article class="docs-body">
+                                @Html.Raw(Model.Document.Content)
+                            </article>
+                        </div>
                     </div>
                 </div>
-            </div>
 
-        </div>
+            </div>
 
-        <div class="col-md-2 docs-page-index position-relative bg-light">
+            <div class="col-md-2 docs-page-index position-relative bg-light">
 
-            <div class="docs-inner-anchors mt-2">
-                <nav class="navbar p-0 pt-2" data-toggle="toc">
-                    <h5>@L["InThisDocument"]</h5>
-                </nav>
+                <div class="docs-inner-anchors mt-2">
+                    <nav class="navbar p-0 pt-2" data-toggle="toc">
+                        <h5>@L["InThisDocument"]</h5>
+                    </nav>
 
-                <div class="row">
-                    <div class="col mt-4 p-0">
-                        <a href="javascript:;" class="scroll-top-btn"><i class="fa fa-chevron-up"></i> @L["GoToTop"]</a>
+                    <div class="row">
+                        <div class="col mt-4 p-0">
+                            <a href="javascript:;" class="scroll-top-btn"><i class="fa fa-chevron-up"></i> @L["GoToTop"]</a>
+                        </div>
                     </div>
                 </div>
+
             </div>
 
-        </div>
+        }
+        else
+        {
+            <div class="col-md-9 p-5 bg-white">
+                <p>@L["DocumentNotFound"]</p>
+                <a href="#">Go to home</a>
+            </div>
+        }
+
     </div>
 </div>