Introduction
I am working/dealing with Indic scripts for my project and I faced many problems due to partial/no support given by libraries/languages/frameworks. I have been trying to resolve my problems. One of them is generating PDFs dynamically.
iTextSharp is a wonderful library for generating PDf Files dynamically. It supports Unicode but not Indic Scripts. iText/iTextSharp has a ready answer for this problem/bug/non-support, but no solution. I am not criticizing iText/iTextsharp here. Because it's Open Source, we have the option to improve it.
Background and Terms
I assume you have a basic idea of iText/iTextSharp and GIST and the terms ISCII, Unicode, IsFoc.
My Intermediate Solution
Going back to history. I use GIST (developed by CDAC) and ISCII.
- Step 1: First you have to convert the Unicode HTML string to an ISCII
HtmlString. - Step 2: Convert the ISCII string to ISFOC and send this string to the iText
HtmlParser. - Step 2 and step 3 can be merged by directly converting the Unicode string to ISFoc. This method is exposed by GIST. Refer to the GIST documentation.
- Step 3: Publish the generated PDF.
Step 1
public static string UniCode2ISCII(string S)
{
if (S == null) { return null; }
try
{
Encoding encFrom = Encoding.GetEncoding(57002);
Encoding encTo = Encoding.GetEncoding(1252);
string str = S;
Byte[] b = encFrom.GetBytes(str);
return encTo.GetString(b);
}
catch { return null; }
}
Step 2
Public Class ISCII2ISFOC
Declare Function Iscii2Isfoc Lib "ismapi32.dll" (ByVal s1 As String,
ByVal s2 As String, ByVal ilen As Integer, ByVal sc As String) As Integer
Public Function ToIsfoc(ByVal str1 As String,ByVal sc as String ) As String
Dim stext1 As String
Dim ilen As Integer
Dim iret As Integer
stext1 = Space(str1.Length * 2)
ilen = str1.Length
iret = Iscii2Isfoc(str1, stext1, ilen, sc)
ToIsfoc = stext1
End Function
End Class
Note: The above method is written in VB.NET so you have to compile it as a separate library and then consume it. I also tried it with C# ref variables (did not get fruitful results; needs to be written in C#).
Step 3
publc void PublishPdf(string IsFochtmlString){
string htmlString = "<html><body><font face=\"DVBSR0XT.ttf\">" +
IsFochtmlString+ "</font></body></html>";
HttpRequest Request = System.Web.HttpContext.Current.Request;
HttpResponse Response = System.Web.HttpContext.Current.Response;
Response.Clear();
Response.ContentType = "application/pdf";
System.IO.MemoryStream m = new System.IO.MemoryStream();
iTextSharp.text.Document document = new iTextSharp.text.Document();
iTextSharp.text.pdf.PdfWriter writer =
iTextSharp.text.pdf.PdfWriter.GetInstance(document, m);
document.Open();
System.Xml.XmlTextReader _xmlr = new System.Xml.XmlTextReader(
new StringReader(htmlString));
iTextSharp.text.html.HtmlParser.Parse(document, _xmlr);
writer.Flush();
Response.OutputStream.Write(m.GetBuffer(), 0, m.GetBuffer().Length);
Response.OutputStream.Flush();
Response.OutputStream.Close();
Response.End();
}
Advantages
- Compact and tiny compared with Unicode (obviously).
Limitations
- It inherits all the limitations from ISCII .
- It supports bilingual only (i.e., English + an Indic language).
- It's not the recommended way/fails when there are multiple languages (can overcome this by splitting the string but it's difficult at runtime, but still you can try; it's possible) because it can't recognize the difference between the languages (Indic).
History
- Article first version posted on 13 Aug. 2008.
