Using XPAGES to pass back binary data

So I would like to write a little article about passing custom generated responses using XPAGES and how to use the for binary output.

Main problem in Lotus Domino editions till 8.5 is that we could not pass back binary data directly to WEB browser (using agent print/printing in form and so on). The only ways were, to create document, attach file, redirect attachment link or create file in shared web dir and pass direct link to user.

Now, when XPAGES with JSF technology comes to place it is possible to do so. Let's get it "how?".

At first You need to create and xpage element and set it render property to false - so nothing to be rendered.
Then You should choose xpage event, where to write the right code, which will serve data. So xpage has following events "beforePageLoad","afterPageLoad","beforeRenderResponse","afterRenderResponse","afterRestoreView". Most interesting for our example are "beforeRenderResponse","afterRenderResponse".

Classes to work with:
1. javax.faces.context.ExternalContext - needed to get response object
2. com.ibm.xsp.webapp.XspHttpServletResponse - needed to get outputstream
3. javax.servlet.ServletOutputStream - stream, where we will write data

XPAGE options to be set:
CreateForm = false
rendered = false

//CODE BLOCK START FOR this example it should be put in beforeRenderResponse
//Initialization
var extContext:javax.faces.context.ExternalContext = facesContext.getexgetExternalContext();
var response:com.ibm.xsp.webapp.XspHttpServletResponse = exCon.getResponse();
var writer:javax.servlet.ServletOutputStream = response.getOutputStream();

//setting response headers for browser to recognize data
response.setContentType("image/gif"); // content type of data, for other binary see mime types or put "application/octet-stream"
response.setHeader("Cache-Control", "no-cache");
response.setHeader("Content-Disposition" ,"attachment; filename=image.gif"); //required if You need to pass it back as file

//convert sample hex to character codes.
var decoded=imgHex.split(" ");
var result=new Array();
for (var i=0;i<decoded.length;i++)
{
result[i]=(parseInt(decoded[i],16))
}
// result is an array containing character codes (byte array). How to prepare for other situations an array You should decide at Your own.
writer.write(result); // just write prepared array to output

//when all output is done. just tell that You have completed the response and close stream
facesContext.responseComplete();
writer.close();




//Sample data
//domino image in hex should move to initialization section
imgHex= "47 49 46 38 39 61 15 00 15 00 e6 00 00 00 00 00 ff ff ff ce 64 66 c9 65 67 e2 7b 7c ff 98 99 ce 65 69 a4 9f a3 68 66 69 a0 b5 ca c8 cc cd c9 cb ca 65 65 63 67 67 65 e5 e5 e2 ca ca c8 c7 c7 c5 f0 f0 ef eb eb ea a8 a8 a7 fe f3 8a fe f2 8c ff f2 8c fe f1 8b d6 d4 d0 ec eb e9 ea e9 e7 c8 c7 c5 f3 ac 38 f2 ad 38 f2 ac 3a f2 ac 3d fc be 59 fc be 5b f9 be 5a d0 cd c8 f4 ab 3a fc bc 5b fc bd 5c fb bc 5d e8 e6 e3 de dc d9 d7 d4 d0 d0 cd c9 d1 cd c8 c0 be bc ee ed ec 81 5b 48 84 59 46 82 5b 4a b7 83 6d b6 82 6d 83 59 49 84 5a 4a b8 81 6d 87 59 4a 84 5a 4c b8 7f 6c ba 7f 6d cd 65 64 cd 67 65 ca 66 66 ff 9a 98 ff 9b 99 fc fc fc ca ca ca ad ad ad ac ac ac 88 88 88 67 67 67 66 66 66 ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 21 f9 04 01 00 00 47 00 2c 00 00 00 00 15 00 15 00 00 07 9e 80 47 82 83 84 85 86 87 88 89 8a 8b 8c 06 03 8c 86 3d 3e 3f 3c 86 42 97 98 99 39 45 05 04 3b 0a 85 42 40 a3 a4 a3 36 14 43 46 02 0f 96 40 11 af b0 3a 14 20 24 30 46 0b ad b0 af 32 14 27 1d 31 07 46 41 ad 19 13 44 12 33 17 25 1c 37 13 18 c2 ad 0e 10 1b 3a 16 26 1f 38 13 0b 40 d0 a1 40 2e 13 33 15 22 1c 2f da 29 dc c3 de 1a 2d 08 21 1e 34 13 2a 18 18 e9 c4 28 0d 0c 35 13 09 2c 2b 23 f6 bc 95 1a 38 aa 1b 21 23 08 13 2a 54 a8 ae 50 90 87 10 23 46 84 44 b1 a2 c5 8b 8c 02 01 00 3b"

REFERENCES, where You could check how to output STRING data.
http://www.wissel.net/blog/d6plinks/SHWL-7MGFBN
http://www-10.lotus.com/ldd/nd85forum.nsf/7756aedc25e6d81285256324005ac76c/1e87cc63dfcf9412852575ae0005079f?OpenDocument - getResponseStream problem.