GroupDocs.Viewer.UI.SelfHost.Api

GroupDocs.Viewer.UI.SelfHost.Api

GroupDocs.Viewer.UI.SelfHost.Api is a self-hosted API implementation for GroupDocs.Viewer.UI that enables document viewing using GroupDocs.Viewer for .NET. It provides a local, self-contained solution for document viewing without requiring cloud services.

This package uses the GroupDocs.Viewer NuGet package. As of 26.8.0 GroupDocs.Viewer ships per-TFM runtime packages that are cross-platform on their own, so this package runs on Windows, Linux, and macOS with no GDI+ or libgdiplus required. The separate GroupDocs.Viewer.UI.SelfHost.Api.CrossPlatform package is deprecated - use this one.

Note: rendering of PSD, PSB, AI, and ONE documents is not available in 26.8.0. Those formats are provided only by the Windows-specific engine build, which this package does not use.

Installation

To use GroupDocs.Viewer.UI.SelfHost.Api in your ASP.NET Core project:

1. Add the required package to your project:

dotnet add package GroupDocs.Viewer.UI.SelfHost.Api

1. Configure the SelfHost API in your Startup class:

using GroupDocs.Viewer.UI.Core;

var builder = WebApplication.CreateBuilder(args);

var viewerType = ViewerType.HtmlWithEmbeddedResources;

builder.Services
    .AddGroupDocsViewerUI();

builder.Services
    .AddControllers()
    .AddGroupDocsViewerSelfHostApi(config =>
    {
        config.SetViewerType(viewerType);
        config.SetLicensePath("GroupDocs.Viewer.lic"); // Path to the license file

        // Configure view options
        config.ConfigureHtmlViewOptions(options => {
            // Configure HTML view options
        });

        config.ConfigurePngViewOptions(options => {
            // Configure PNG view options
        });

        config.ConfigureJpgViewOptions(options => {
            // Configure JPG view options
        });

        config.ConfigurePdfViewOptions(options => {
            // Configure PDF view options
        });

        // Configure internal caching
        config.ConfigureInternalCaching(options => {
            // Configure caching options
        });
    })
    .AddLocalStorage("./Files");

var app = builder.Build();

app
    .UseRouting()
    .UseEndpoints(endpoints =>
    {
        endpoints.MapGroupDocsViewerUI(options =>
        {
            options.UIPath = "/viewer";
            options.ApiEndpoint = "/viewer-api";
        });
        endpoints.MapGroupDocsViewerApi(options =>
        {
            options.ApiPath = "/viewer-api";
        });
    });

await app.RunAsync();

Configuration Options

The SelfHost API implementation provides the following configuration options:

• LicensePath (Optional): Path to your GroupDocs.Viewer license file.
• ViewerType (Optional): The type of viewer to use. Options include:
  • HtmlWithEmbeddedResources (default)
  • HtmlWithExternalResources
  • Png
  • Jpg

View Options Configuration

You can configure specific view options for different output formats:

config.ConfigureHtmlViewOptions(options => {
    // Configure HTML view options
});

config.ConfigurePngViewOptions(options => {
    // Configure PNG view options
});

config.ConfigureJpgViewOptions(options => {
    // Configure JPG view options
});

config.ConfigurePdfViewOptions(options => {
    // Configure PDF view options
});

Internal Caching

The internal caching mechanism stores rendered pages and document information in memory to improve performance:

• Uses memory cache to store rendered pages and document info
• Caches are keyed by document path and rendering parameters
• Default cache duration is 5 minutes (configurable)
• Automatically evicts old entries when memory is constrained
• Significantly improves performance for frequently accessed documents

The cache can be configured via the options shown in the example:

// Configure internal caching
config.ConfigureInternalCaching(options => {
    // Configure caching options
    options.DisableInternalCache(); // Disables internal caching
    options.SetCacheEntryExpirationTimeoutMinutes(60); // Default values is 5 minutes
});

Performance Considerations

When using GroupDocs.Viewer.UI.SelfHost.Api:

1. Processing is done locally on your server
2. Memory usage depends on document size and complexity
3. Internal caching can improve performance for repeated requests
4. Best suited for:
   • Applications requiring local document processing
   • Environments with limited internet connectivity
   • Scenarios where data privacy is important
5. Performance depends on:
   • Server hardware specifications
   • Document size and complexity
   • Chosen viewer type
   • Caching configuration

License

This project is licensed under the MIT License - see the LICENSE.txt file for details.