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 which relies on System.Drawing.Common and is optimized for Windows environments. For Linux deployments, we recommend using GroupDocs.Viewer.UI.SelfHost.Api.CrossPlatform instead, which utilizes GroupDocs.Viewer.CrossPlatform with its cross-platform graphical engine.

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.