FolkerKinzel.DataUrls

.NET library that supports working with "data" URLs (RFC 2397)

Project Reference

The library contains the static DataUrl class that supports the "data" URL scheme (RFC 2397), which allows to embed data in a URI. The DataUrl class allows

• building "data" URL strings from files, byte arrays or text,
• parsing "data" URL strings as DataUrlInfo structs in order to examine their content without having to allocate a lot of sub-strings, and to enable the comparison of "data" URLs for equality,
• retrieving the embedded data from "data" URL strings,
• retrieving an appropriate file type extension for the embedded data.

The library is designed to support performance and small heap allocation.

Version History

Example:

Creating and parsing a "data" URL:

using FolkerKinzel.DataUrls;
using FolkerKinzel.DataUrls.Extensions;
using System.Diagnostics;

namespace Examples;

public static class DataUrlExample
{
    public static void Example()
    {
        // Creates a temporary JPG file for testing.
        string photoFilePath = CreatePhotoFile();

        // Creates a "data" URL string from the file.
        // The MIME type comes from the file type extension
        // (if not provided as argument):
        string dataUrl = DataUrl.FromFile(photoFilePath);

        // (The photo file is no longer needed.)
        File.Delete(photoFilePath);

        // Uncomment this to show the content of the
        // "data" URL in the Microsoft Edge browser.
        // (Make shure you have this browser installed.):
        // ShowPictureInMicrosoftEdge(dataUrl);

        Console.WriteLine(dataUrl);
        Console.WriteLine();
        Console.WriteLine("Is \"data\" URL:  {0}", dataUrl.IsDataUrl());
        Console.WriteLine();

        // Parse the content of the "data" URL:
        _ = DataUrl.TryParse(dataUrl, out DataUrlInfo info);

        Console.WriteLine("Data Type:      {0}", info.DataType);
        Console.WriteLine("MIME Type:      {0}", info.MimeType);
        Console.WriteLine("File Type Ext.: {0}", info.GetFileTypeExtension());
        Console.WriteLine("Data Encoding:  {0}", info.Encoding);
        Console.WriteLine();

        if (info.TryGetData(out EmbeddedData data))
        {
            // EmbeddedData is a union that contains either a
            // byte array or a string.

            Console.WriteLine(data);
        }
    }

    /// <summary>
    /// Creates a temporary photo file. The data comes from a given "data" URL.
    /// </summary>
    /// <returns>The file path.</returns>
    private static string CreatePhotoFile()
    {
        const string url = "data:image/jpeg;base64,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";
        string path = "";

        // Tries to get the embedded data as Byte array
        // (and an appropriate file type extension too):
        if (DataUrl.TryGetBytes(url,
                                out byte[]? bytes,
                                out string? fileTypeExtension) && bytes.Length > 0)
        {
            path = Path.Combine(
                Directory.GetCurrentDirectory(), $"{Guid.NewGuid()}{fileTypeExtension}");
            File.WriteAllBytes(path, bytes);
        }

        return path;
    }

    /// <summary>
    /// Displays the content of a "data" URL in the Edge browser.
    /// </summary>
    /// <param name="dataUrl">The "data" URL.</param>
    private static void ShowPictureInMicrosoftEdge(string dataUrl)
    {
        var process = new Process();
        process.StartInfo.UseShellExecute = true;
        process.StartInfo.FileName = "msedge";
        process.StartInfo.Arguments = dataUrl;
        _ = process.Start();
    }
}

/*
Console Output:

data:image/jpeg;base64,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

Is "data" URL:  True

Data Type:      Binary
MIME Type:      image/jpeg
File Type Ext.: .jpg
Data Encoding:  Base64

System.Byte[]: 2472 Bytes
 */