Viewer-api customize for stream usage and not storage

[AlperenCinkaya]

Hello, I want to implement groupdocs viewer. I download the sample .Net Core project.
I want to modify this project only I need to view a document when endpoint calls. And show that document only.

• I have file on stream.
• I dont want to download and put it on /storage folder.

In example .Net Core demo project in program.cs file is there a way to only set like comment below
image.png (10.3 KB)

My usage of viewer is like Im going to host this example viewer project standole. And display from <‘iframe’> in my project. So in my project its only open modal and show viewer in iframe and render only one document per time. Then its closing the viewer. I want to use viewer search and other download tools as well. So I dont want only to show document content.
groupdocs2.PNG (8.0 KB)

If I can complete this my company will buy this product for our usage.

[vladimir.litvinchik]

@AlperenCinkaya

You can pass a file ID or path using a query string parameter e.g. ?file=invoice.pdf. You have to implement and register storage and if needed file type resolver

// ConfigureServices
services.AddTransient<IFileStorage, MyFileStorage>();
services.AddTransient<IFileTypeResolver, MyFileTypeResolver>();

// Implementation

 class MyFileStorage : IFileStorage
 {
     public Task<IEnumerable<FileSystemEntry>> ListDirsAndFilesAsync(string dirPath)
     {
         throw new NotImplementedException();   
     } 
     public Task<byte[]> ReadFileAsync(string filePath)
     {
         return File.ReadAllBytesAsync("./Storage/sample.docx");
     } 
     public Task<string> WriteFileAsync(string fileName, byte[] bytes, bool rewrite)
     {
         throw new NotImplementedException();
     }
 } 

 class MyFileTypeResolver : IFileTypeResolver
 {
     public Task<FileType> ResolveFileTypeAsync(string filePath)
     {
         // resolve file type by file path
         return Task.FromResult<FileType>(FileType.DOCX);
     }
 }

See this sample application for more details.

Let us know if you have any questions.

[AlperenCinkaya]

Hello, thank you very much. I modified the project you send me and now its working. I override the ReadFileAsync for downloading file stream from my server and get byte[] to view.

groupDocs5.PNG (57.3 KB)

But I want to keep download button functionality and remove the DisableFileDownload() from config.
But problem is when I click download its getting like from (string filePath) which in my case its encoded Id fields. And not real file name. So I need to dynamically set fileName.
How can I override that in startup?

groupDocs6.PNG (3.6 KB)

[vladimir.litvinchik]

@AlperenCinkaya

I’ve added support for setting the filename when downloading a file. The solution is similar to the one shared above.

 services.AddTransient<IFileNameResolver, MyFileInfoResolver>();

 //...

 class MyFileInfoResolver : IFileNameResolver
 {
     public Task<string> ResolveFileNameAsync(string filePath)
     {
         return Task.FromResult<string>("my-file-name.docx");
     }
 }

You have to use the latest package versions and .NET 6 or above as a target framework as shown in the sample app.

[vladimir.litvinchik]

We have opened the following new ticket(s) in our internal issue tracking system and will deliver their fixes according to the terms mentioned in Free Support Policies.

Issue ID(s): VIEWERNET-4238

You can obtain Paid Support services if you need support on a priority basis, along with the direct access to our Paid Support management team.