wkhtmltopdf outputstream & download - diaglog

Question

is it possible to get a pdf stream created by wkhtmltopdf from any html file and popup a download dialog in IE/Firefox/Chrome etc.?

At the moment I get my outputstre

Answer 1

My take on this based on @Nenotlep answer. This is only the pdf generation part.

I am using async. I created a new StreamWriter because wkhtmltopdf is expecting utf-8 by default but it is set to something else when the process starts.

I removed p.WaitForExit(...) since I wasn't handling if it fails and it would hang anyway on await tStandardOutput. If timeout is needed, then you would have to call Wait on the different tasks with a cancellationtoken or timeout and handle accordingly.

public static async Task GeneratePdf(string html, Size pageSize)
{
    ProcessStartInfo psi = new ProcessStartInfo
    {
        FileName = @"C:\PROGRA~1\WKHTML~1\wkhtmltopdf.exe",
        UseShellExecute = false,
        CreateNoWindow = true,
        RedirectStandardInput = true,
        RedirectStandardOutput = true,
        RedirectStandardError = true,
        Arguments = "-q -n --disable-smart-shrinking " 
            + (pageSize.IsEmpty ? "" : "--page-width " + pageSize.Width 
            + "mm --page-height " + pageSize.Height + "mm") + " - -";
    };

    using (var p = Process.Start(psi))
    using (var pdfSream = new MemoryStream())
    using (var utf8Writer = new StreamWriter(p.StandardInput.BaseStream, 
                            Encoding.UTF8))
    {
        await utf8Writer.WriteAsync(html);
        utf8Writer.Close();
        var tStdOut = p.StandardOutput.BaseStream.CopyToAsync(pdfSream);
        var tStdError = p.StandardError.ReadToEndAsync();

        await tStandardOutput;
        string errors = await tStandardError;

        if (!string.IsNullOrEmpty(errors))
        {
            //deal with errors
        }

        return pdfSream.ToArray();
    }
}

Things I haven't included in there but could be useful as a reference:

• you can pass the authentication cookie if needed using --cookie
• you can set the base tag with href pointing to the server of your html page for additional requests (css, image, etc) in your html page