Generating pdf from html using Prawn - ruby-on-rails

Question

I want to generate pdf from html. A gem prawn seems to be the most popular one for that. I downloaded the manual for it, but there is no information about how to generate pdf from html.
In particular, I need it to work on Heroku also, but that's the second goal.
So how can I generate pdf from html using Prawn?

Answer 1

Look for Pdfkit, it's second most popular gem RubyToolbox. It generate PDF from HTML using wkhtmltopdf. On RailsCasts is one older tutorial.

Answer 2

This is a sample code to generate pdf from html using prawn
/// <summary>
/// Convert the HTML code from the specified URL to a PDF document
and send the document to the browser
/// </summary>
private void ConvertURLToPDF()
{
string urlToConvert = textBoxWebPageURL.Text.Trim();
// Create the PDF converter. Optionally the HTML viewer width can
be specified as parameter
// The default HTML viewer width is 1024 pixels.
PdfConverter pdfConverter = new PdfConverter();
// set the license key - required
pdfConverter.LicenseKey = "R8nYyNnI2MjRxtjI29nG2drG0dHR0Q==";
// set the converter options - optional
pdfConverter.PdfDocumentOptions.PdfPageSize = PdfPageSize.A4;
pdfConverter.PdfDocumentOptions.PdfCompressionLevel = PdfCompressionLevel.Normal;
pdfConverter.PdfDocumentOptions.PdfPageOrientation = PdfPageOrientation.Portrait;
// set if header and footer are shown in the PDF - optional - default
is false
pdfConverter.PdfDocumentOptions.ShowHeader = cbAddHeader.Checked;
pdfConverter.PdfDocumentOptions.ShowFooter = cbAddFooter.Checked;
// set if the HTML content is resized if necessary to fit the PDF
page width - default is true
pdfConverter.PdfDocumentOptions.FitWidth = cbFitWidth.Checked;
// set the embedded fonts option - optional - default is false
pdfConverter.PdfDocumentOptions.EmbedFonts = cbEmbedFonts.Checked;
// set the live HTTP links option - optional - default is true
pdfConverter.PdfDocumentOptions.LiveUrlsEnabled = cbLiveLinks.Checked;
// set if the JavaScript is enabled during conversion to a PDF - default
is true
pdfConverter.JavaScriptEnabled = cbClientScripts.Checked;
// set if the images in PDF are compressed with JPEG to reduce the
PDF document size - default is true
pdfConverter.PdfDocumentOptions.JpegCompressionEnabled = cbJpegCompression.Checked;
// enable auto-generated bookmarks for a specified list of HTML selectors
(e.g. H1 and H2)
if (cbBookmarks.Checked)
{
pdfConverter.PdfBookmarkOptions.HtmlElementSelectors = new string[] { "H1", "H2" };
}
// add HTML header
if (cbAddHeader.Checked)
AddHeader(pdfConverter);
// add HTML footer
if (cbAddFooter.Checked)
AddFooter(pdfConverter);
// Performs the conversion and get the pdf document bytes that can
// be saved to a file or sent as a browser response
byte[] pdfBytes = pdfConverter.GetPdfBytesFromUrl(urlToConvert);
// send the PDF document as a response to the browser for download
System.Web.HttpResponse response = System.Web.HttpContext.Current.Response;
response.Clear();
response.AddHeader("Content-Type", "application/pdf");
if (radioAttachment.Checked)
response.AddHeader("Content-Disposition",
String.Format("attachment; filename=GettingStarted.pdf; size={0}",
pdfBytes.Length.ToString()));
else
response.AddHeader("Content-Disposition",
String.Format("inline; filename=GettingStarted.pdf; size={0}",
pdfBytes.Length.ToString()));
response.BinaryWrite(pdfBytes);
// Note: it is important to end the response, otherwise the ASP.NET
// web page will render its content to PDF document stream
response.End();
}